28 files changed, 2583 insertions, 1124 deletions

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs b/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
index 4c195e1..57c5898 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
@@ -69,6 +69,8 @@ public sealed class BSCharacter : BSPhysObject
     private OMV.Vector3 _appliedVelocity;   // the last velocity applied to the avatar
     private float _currentFriction;         // the friction currently being used (changed by setVelocity).
 
+    private BSVMotor _velocityMotor;
+
     private OMV.Vector3 _PIDTarget;
     private bool _usePID;
     private float _PIDTau;
@@ -89,6 +91,18 @@ public sealed class BSCharacter : BSPhysObject
         if (_size.X == 0f) _size.X = PhysicsScene.Params.avatarCapsuleDepth;
         if (_size.Y == 0f) _size.Y = PhysicsScene.Params.avatarCapsuleWidth;
 
+        // A motor to control the acceleration and deceleration of the avatar movement.
+        // _velocityMotor = new BSVMotor("BSCharacter.Velocity", 3f, 5f, BSMotor.InfiniteVector, 1f);
+        // _velocityMotor = new BSPIDVMotor("BSCharacter.Velocity", 3f, 5f, BSMotor.InfiniteVector, 1f);
+        // Infinite decay and timescale values so motor only changes current to target values.
+        _velocityMotor = new BSVMotor("BSCharacter.Velocity", 
+                                            0.2f,                       // time scale
+                                            BSMotor.Infinite,           // decay time scale
+                                            BSMotor.InfiniteVector,     // friction timescale
+                                            1f                          // efficiency
+        );
+        _velocityMotor.PhysicsScene = PhysicsScene; // DEBUG DEBUG so motor will output detail log messages.
+
         _flying = isFlying;
         _orientation = OMV.Quaternion.Identity;
         _velocity = OMV.Vector3.Zero;
@@ -105,12 +119,12 @@ public sealed class BSCharacter : BSPhysObject
         DetailLog("{0},BSCharacter.create,call,size={1},scale={2},density={3},volume={4},mass={5}",
                             LocalID, _size, Scale, _avatarDensity, _avatarVolume, RawMass);
 
-        // do actual create at taint time
+        // do actual creation in taint time
         PhysicsScene.TaintedObject("BSCharacter.create", delegate()
         {
             DetailLog("{0},BSCharacter.create,taint", LocalID);
             // New body and shape into PhysBody and PhysShape
-            PhysicsScene.Shapes.GetBodyAndShape(true, PhysicsScene.World, this, null, null);
+            PhysicsScene.Shapes.GetBodyAndShape(true, PhysicsScene.World, this);
 
             SetPhysicalProperties();
         });
@@ -124,7 +138,9 @@ public sealed class BSCharacter : BSPhysObject
         PhysicsScene.TaintedObject("BSCharacter.destroy", delegate()
         {
             PhysicsScene.Shapes.DereferenceBody(PhysBody, true, null);
+            PhysBody.Clear();
             PhysicsScene.Shapes.DereferenceShape(PhysShape, true, null);
+            PhysShape.Clear();
         });
     }
 
@@ -136,6 +152,10 @@ public sealed class BSCharacter : BSPhysObject
         ForcePosition = _position;
         // Set the velocity and compute the proper friction
         ForceVelocity = _velocity;
+        // Setting the current and target in the motor will cause it to start computing any deceleration.
+        _velocityMotor.Reset();
+        _velocityMotor.SetCurrent(_velocity);
+        _velocityMotor.SetTarget(_velocity);
 
         // This will enable or disable the flying buoyancy of the avatar.
         // Needs to be reset especially when an avatar is recreated after crossing a region boundry.
@@ -165,9 +185,8 @@ public sealed class BSCharacter : BSPhysObject
         BulletSimAPI.UpdateSingleAabb2(PhysicsScene.World.ptr, PhysBody.ptr);
 
         // Do this after the object has been added to the world
-        BulletSimAPI.SetCollisionFilterMask2(PhysBody.ptr,
-                        (uint)CollisionFilterGroups.AvatarFilter,
-                        (uint)CollisionFilterGroups.AvatarMask);
+        PhysBody.collisionType = CollisionType.Avatar;
+        PhysBody.ApplyCollisionMask();
     }
 
     public override void RequestPhysicsterseUpdate()
@@ -187,6 +206,11 @@ public sealed class BSCharacter : BSPhysObject
         set {
             // When an avatar's size is set, only the height is changed.
             _size = value;
+            // Old versions of ScenePresence passed only the height. If width and/or depth are zero,
+            //     replace with the default values.
+            if (_size.X == 0f) _size.X = PhysicsScene.Params.avatarCapsuleDepth;
+            if (_size.Y == 0f) _size.Y = PhysicsScene.Params.avatarCapsuleWidth;
+
             ComputeAvatarScale(_size);
             ComputeAvatarVolumeAndMass();
             DetailLog("{0},BSCharacter.setSize,call,size={1},scale={2},density={3},volume={4},mass={5}",
@@ -194,15 +218,18 @@ public sealed class BSCharacter : BSPhysObject
 
             PhysicsScene.TaintedObject("BSCharacter.setSize", delegate()
             {
-                BulletSimAPI.SetLocalScaling2(PhysShape.ptr, Scale);
-                UpdatePhysicalMassProperties(RawMass);
+                if (PhysBody.HasPhysicalBody && PhysShape.HasPhysicalShape)
+                {
+                    BulletSimAPI.SetLocalScaling2(PhysShape.ptr, Scale);
+                    UpdatePhysicalMassProperties(RawMass);
+                    // Make sure this change appears as a property update event
+                    BulletSimAPI.PushUpdate2(PhysBody.ptr);
+                }
             });
 
         }
     }
 
-    public override OMV.Vector3 Scale { get; set; }
-
     public override PrimitiveBaseShape Shape
     {
         set { BaseShape = value; }
@@ -230,13 +257,15 @@ public sealed class BSCharacter : BSPhysObject
     public override void ZeroMotion(bool inTaintTime)
     {
         _velocity = OMV.Vector3.Zero;
+        _velocityMotor.Zero();
         _acceleration = OMV.Vector3.Zero;
         _rotationalVelocity = OMV.Vector3.Zero;
 
         // Zero some other properties directly into the physics engine
         PhysicsScene.TaintedObject(inTaintTime, "BSCharacter.ZeroMotion", delegate()
         {
-            BulletSimAPI.ClearAllForces2(PhysBody.ptr);
+            if (PhysBody.HasPhysicalBody)
+                BulletSimAPI.ClearAllForces2(PhysBody.ptr);
         });
     }
     public override void ZeroAngularMotion(bool inTaintTime)
@@ -245,10 +274,13 @@ public sealed class BSCharacter : BSPhysObject
 
         PhysicsScene.TaintedObject(inTaintTime, "BSCharacter.ZeroMotion", delegate()
         {
-            BulletSimAPI.SetInterpolationAngularVelocity2(PhysBody.ptr, OMV.Vector3.Zero);
-            BulletSimAPI.SetAngularVelocity2(PhysBody.ptr, OMV.Vector3.Zero);
-            // The next also get rid of applied linear force but the linear velocity is untouched.
-            BulletSimAPI.ClearForces2(PhysBody.ptr);
+            if (PhysBody.HasPhysicalBody)
+            {
+                BulletSimAPI.SetInterpolationAngularVelocity2(PhysBody.ptr, OMV.Vector3.Zero);
+                BulletSimAPI.SetAngularVelocity2(PhysBody.ptr, OMV.Vector3.Zero);
+                // The next also get rid of applied linear force but the linear velocity is untouched.
+                BulletSimAPI.ClearForces2(PhysBody.ptr);
+            }
         });
     }
 
@@ -273,7 +305,8 @@ public sealed class BSCharacter : BSPhysObject
             PhysicsScene.TaintedObject("BSCharacter.setPosition", delegate()
             {
                 DetailLog("{0},BSCharacter.SetPosition,taint,pos={1},orient={2}", LocalID, _position, _orientation);
-                BulletSimAPI.SetTranslation2(PhysBody.ptr, _position, _orientation);
+                if (PhysBody.HasPhysicalBody)
+                    BulletSimAPI.SetTranslation2(PhysBody.ptr, _position, _orientation);
             });
         }
     }
@@ -297,6 +330,15 @@ public sealed class BSCharacter : BSPhysObject
     {
         bool ret = false;
 
+        // TODO: check for out of bounds
+        if (!PhysicsScene.TerrainManager.IsWithinKnownTerrain(_position))
+        {
+            // The character is out of the known/simulated area.
+            // Upper levels of code will handle the transition to other areas so, for
+            //     the time, we just ignore the position.
+            return ret;
+        }
+
         // If below the ground, move the avatar up
         float terrainHeight = PhysicsScene.TerrainManager.GetTerrainHeightAtXYZ(_position);
         if (Position.Z < terrainHeight)
@@ -307,7 +349,7 @@ public sealed class BSCharacter : BSPhysObject
         }
         if ((CurrentCollisionFlags & CollisionFlags.BS_FLOATS_ON_WATER) != 0)
         {
-            float waterHeight = PhysicsScene.GetWaterLevelAtXYZ(_position);
+            float waterHeight = PhysicsScene.TerrainManager.GetWaterLevelAtXYZ(_position);
             if (Position.Z < waterHeight)
             {
                 _position.Z = waterHeight;
@@ -315,7 +357,6 @@ public sealed class BSCharacter : BSPhysObject
             }
         }
 
-        // TODO: check for out of bounds
         return ret;
     }
 
@@ -332,7 +373,8 @@ public sealed class BSCharacter : BSPhysObject
             PhysicsScene.TaintedObject(inTaintTime, "BSCharacter.PositionSanityCheck", delegate()
             {
                 DetailLog("{0},BSCharacter.PositionSanityCheck,taint,pos={1},orient={2}", LocalID, _position, _orientation);
-                BulletSimAPI.SetTranslation2(PhysBody.ptr, _position, _orientation);
+                if (PhysBody.HasPhysicalBody)
+                    BulletSimAPI.SetTranslation2(PhysBody.ptr, _position, _orientation);
             });
             ret = true;
         }
@@ -359,7 +401,8 @@ public sealed class BSCharacter : BSPhysObject
             PhysicsScene.TaintedObject("BSCharacter.SetForce", delegate()
             {
                 DetailLog("{0},BSCharacter.setForce,taint,force={1}", LocalID, _force);
-                BulletSimAPI.SetObjectForce2(PhysBody.ptr, _force);
+                if (PhysBody.HasPhysicalBody)
+                    BulletSimAPI.SetObjectForce2(PhysBody.ptr, _force);
             });
         }
     }
@@ -376,10 +419,38 @@ public sealed class BSCharacter : BSPhysObject
 
     public override OMV.Vector3 GeometricCenter { get { return OMV.Vector3.Zero; } }
     public override OMV.Vector3 CenterOfMass { get { return OMV.Vector3.Zero; } }
+
+    // Sets the target in the motor. This starts the changing of the avatar's velocity.
+    public override OMV.Vector3 TargetVelocity
+    {
+        get
+        {
+            return _velocityMotor.TargetValue;
+        }
+        set
+        {
+            DetailLog("{0},BSCharacter.setTargetVelocity,call,vel={1}", LocalID, value);
+            OMV.Vector3 targetVel = value;
+            PhysicsScene.TaintedObject("BSCharacter.setTargetVelocity", delegate()
+            {
+                float timeStep = 0.089f;    // DEBUG DEBUG FIX FIX FIX
+                _velocityMotor.Reset();
+                _velocityMotor.SetTarget(targetVel);
+                _velocityMotor.SetCurrent(_velocity);
+                // Compute a velocity value and make sure it gets pushed into the avatar.
+                // This makes sure the avatar will start from a stop.
+                ForceVelocity = _velocityMotor.Step(timeStep);
+            });
+        }
+    }
+    // Directly setting velocity means this is what the user really wants now.
     public override OMV.Vector3 Velocity {
         get { return _velocity; }
         set {
             _velocity = value;
+            _velocityMotor.Reset();
+            _velocityMotor.SetCurrent(_velocity);
+            _velocityMotor.SetTarget(_velocity);
             // m_log.DebugFormat("{0}: set velocity = {1}", LogHeader, _velocity);
             PhysicsScene.TaintedObject("BSCharacter.setVelocity", delegate()
             {
@@ -391,6 +462,8 @@ public sealed class BSCharacter : BSPhysObject
     public override OMV.Vector3 ForceVelocity {
         get { return _velocity; }
         set {
+            PhysicsScene.AssertInTaintTime("BSCharacter.ForceVelocity");
+
             // Depending on whether the avatar is moving or not, change the friction
             //    to keep the avatar from slipping around
             if (_velocity.Length() == 0)
@@ -398,7 +471,8 @@ public sealed class BSCharacter : BSPhysObject
                 if (_currentFriction != PhysicsScene.Params.avatarStandingFriction)
                 {
                     _currentFriction = PhysicsScene.Params.avatarStandingFriction;
-                    BulletSimAPI.SetFriction2(PhysBody.ptr, _currentFriction);
+                    if (PhysBody.HasPhysicalBody)
+                        BulletSimAPI.SetFriction2(PhysBody.ptr, _currentFriction);
                 }
             }
             else
@@ -406,7 +480,8 @@ public sealed class BSCharacter : BSPhysObject
                 if (_currentFriction != PhysicsScene.Params.avatarFriction)
                 {
                     _currentFriction = PhysicsScene.Params.avatarFriction;
-                    BulletSimAPI.SetFriction2(PhysBody.ptr, _currentFriction);
+                    if (PhysBody.HasPhysicalBody)
+                        BulletSimAPI.SetFriction2(PhysBody.ptr, _currentFriction);
                 }
             }
             _velocity = value;
@@ -443,8 +518,11 @@ public sealed class BSCharacter : BSPhysObject
             // m_log.DebugFormat("{0}: set orientation to {1}", LogHeader, _orientation);
             PhysicsScene.TaintedObject("BSCharacter.setOrientation", delegate()
             {
-                // _position = BulletSimAPI.GetPosition2(BSBody.ptr);
-                BulletSimAPI.SetTranslation2(PhysBody.ptr, _position, _orientation);
+                if (PhysBody.HasPhysicalBody)
+                {
+                    // _position = BulletSimAPI.GetPosition2(BSBody.ptr);
+                    BulletSimAPI.SetTranslation2(PhysBody.ptr, _position, _orientation);
+                }
             });
         }
     }
@@ -482,6 +560,13 @@ public sealed class BSCharacter : BSPhysObject
         get { return _flying; }
         set {
             _flying = value;
+
+            // Velocity movement is different when flying: flying velocity degrades over time.
+            if (_flying)
+                _velocityMotor.TargetValueDecayTimeScale = 1f;
+            else
+                _velocityMotor.TargetValueDecayTimeScale = BSMotor.Infinite;
+
             // simulate flying by changing the effect of gravity
             Buoyancy = ComputeBuoyancyFromFlying(_flying);
         }
@@ -517,10 +602,13 @@ public sealed class BSCharacter : BSPhysObject
             _floatOnWater = value;
             PhysicsScene.TaintedObject("BSCharacter.setFloatOnWater", delegate()
             {
-                if (_floatOnWater)
-                    CurrentCollisionFlags = BulletSimAPI.AddToCollisionFlags2(PhysBody.ptr, CollisionFlags.BS_FLOATS_ON_WATER);
-                else
-                    CurrentCollisionFlags = BulletSimAPI.RemoveFromCollisionFlags2(PhysBody.ptr, CollisionFlags.BS_FLOATS_ON_WATER);
+                if (PhysBody.HasPhysicalBody)
+                {
+                    if (_floatOnWater)
+                        CurrentCollisionFlags = BulletSimAPI.AddToCollisionFlags2(PhysBody.ptr, CollisionFlags.BS_FLOATS_ON_WATER);
+                    else
+                        CurrentCollisionFlags = BulletSimAPI.RemoveFromCollisionFlags2(PhysBody.ptr, CollisionFlags.BS_FLOATS_ON_WATER);
+                }
             });
         }
     }
@@ -549,11 +637,15 @@ public sealed class BSCharacter : BSPhysObject
     }
     public override float ForceBuoyancy {
         get { return _buoyancy; }
-        set { _buoyancy = value;
+        set { 
+            PhysicsScene.AssertInTaintTime("BSCharacter.ForceBuoyancy");
+
+            _buoyancy = value;
             DetailLog("{0},BSCharacter.setForceBuoyancy,taint,buoy={1}", LocalID, _buoyancy);
             // Buoyancy is faked by changing the gravity applied to the object
             float grav = PhysicsScene.Params.gravity * (1f - _buoyancy);
-            BulletSimAPI.SetGravity2(PhysBody.ptr, new OMV.Vector3(0f, 0f, grav));
+            if (PhysBody.HasPhysicalBody)
+                BulletSimAPI.SetGravity2(PhysBody.ptr, new OMV.Vector3(0f, 0f, grav));
         }
     }
 
@@ -599,7 +691,8 @@ public sealed class BSCharacter : BSPhysObject
             PhysicsScene.TaintedObject("BSCharacter.AddForce", delegate()
             {
                 DetailLog("{0},BSCharacter.setAddForce,taint,addedForce={1}", LocalID, _force);
-                BulletSimAPI.SetObjectForce2(PhysBody.ptr, _force);
+                if (PhysBody.HasPhysicalBody)
+                    BulletSimAPI.SetObjectForce2(PhysBody.ptr, _force);
             });
         }
         else
@@ -616,9 +709,6 @@ public sealed class BSCharacter : BSPhysObject
 
     private void ComputeAvatarScale(OMV.Vector3 size)
     {
-        // The 'size' given by the simulator is the mid-point of the avatar
-        //    and X and Y are unspecified.
-
         OMV.Vector3 newScale = size;
         // newScale.X = PhysicsScene.Params.avatarCapsuleWidth;
         // newScale.Y = PhysicsScene.Params.avatarCapsuleDepth;
@@ -667,6 +757,22 @@ public sealed class BSCharacter : BSPhysObject
         LastEntityProperties = CurrentEntityProperties;
         CurrentEntityProperties = entprop;
 
+        // Avatars don't respond to world friction, etc. They only go the speed I tell them too.
+        // Special kludge here for falling. Even though the target velocity might not have a
+        //     Z component, the avatar could be falling (walked off a ledge, stopped flying, ...)
+        //     and that velocity component must be retained.
+        float timeStep = 0.089f;        // DEBUG DEBUG FIX FIX FIX
+        OMV.Vector3 stepVelocity = _velocityMotor.Step(timeStep);
+        // Remove next line so avatars don't fly up forever. DEBUG DEBUG this is only temporary.
+        // stepVelocity.Z += entprop.Velocity.Z;
+        _velocity = stepVelocity;
+        BulletSimAPI.SetLinearVelocity2(PhysBody.ptr, _velocity);
+        /*
+        OMV.Vector3 stepVelocity = _velocityMotor.Step(timeStep);
+        OMV.Vector3 avVel = new OMV.Vector3(stepVelocity.X, stepVelocity.Y, entprop.Velocity.Z);
+        _velocity = avVel;
+        BulletSimAPI.SetLinearVelocity2(PhysBody.ptr, avVel);
+        
         if (entprop.Velocity != LastEntityProperties.Velocity)
         {
             // Changes in the velocity are suppressed in avatars.
@@ -675,9 +781,10 @@ public sealed class BSCharacter : BSPhysObject
             _velocity = avVel;
             BulletSimAPI.SetLinearVelocity2(PhysBody.ptr, avVel);
         }
+         */
 
         // Tell the linkset about value changes
-        Linkset.UpdateProperties(this);
+        Linkset.UpdateProperties(this, true);
 
         // Avatars don't report their changes the usual way. Changes are checked for in the heartbeat loop.
         // base.RequestPhysicsterseUpdate();
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSConstraint.cs b/OpenSim/Region/Physics/BulletSPlugin/BSConstraint.cs
index 65fac00..6b1e304 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSConstraint.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSConstraint.cs
@@ -57,7 +57,7 @@ public abstract class BSConstraint : IDisposable
         if (m_enabled)
         {
             m_enabled = false;
-            if (m_constraint.ptr != IntPtr.Zero)
+            if (m_constraint.HasPhysicalConstraint)
             {
                 bool success = BulletSimAPI.DestroyConstraint2(m_world.ptr, m_constraint.ptr);
                 m_world.physicsScene.DetailLog("{0},BSConstraint.Dispose,taint,id1={1},body1={2},id2={3},body2={4},success={5}",
@@ -65,7 +65,7 @@ public abstract class BSConstraint : IDisposable
                                     m_body1.ID, m_body1.ptr.ToString("X"),
                                     m_body2.ID, m_body2.ptr.ToString("X"),
                                     success);
-                m_constraint.ptr = System.IntPtr.Zero;
+                m_constraint.Clear();
             }
         }
     }
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSConstraint6Dof.cs b/OpenSim/Region/Physics/BulletSPlugin/BSConstraint6Dof.cs
index 23ef052..b073555 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSConstraint6Dof.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSConstraint6Dof.cs
@@ -65,7 +65,7 @@ public sealed class BSConstraint6Dof : BSConstraint
         m_world = world;
         m_body1 = obj1;
         m_body2 = obj2;
-        if (obj1.ptr == IntPtr.Zero || obj2.ptr == IntPtr.Zero)
+        if (!obj1.HasPhysicalBody || !obj2.HasPhysicalBody)
         {
             world.physicsScene.DetailLog("{0},BS6DOFConstraint,badBodyPtr,wID={1}, rID={2}, rBody={3}, cID={4}, cBody={5}",
                             BSScene.DetailLogZero, world.worldID,
@@ -83,7 +83,7 @@ public sealed class BSConstraint6Dof : BSConstraint
             world.physicsScene.DetailLog("{0},BS6DofConstraint,createMidPoint,wID={1}, csrt={2}, rID={3}, rBody={4}, cID={5}, cBody={6}",
                                 BSScene.DetailLogZero, world.worldID, m_constraint.ptr.ToString("X"),
                                 obj1.ID, obj1.ptr.ToString("X"), obj2.ID, obj2.ptr.ToString("X"));
-            if (m_constraint.ptr == IntPtr.Zero)
+            if (!m_constraint.HasPhysicalConstraint)
             {
                 world.physicsScene.Logger.ErrorFormat("{0} Failed creation of 6Dof constraint. rootID={1}, childID={2}",
                                 LogHeader, obj1.ID, obj2.ID);
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs b/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
index dbc9039..a5acd86 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
@@ -24,30 +24,17 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
-
-/* RA: June 14, 2011. Copied from ODEDynamics.cs and converted to
- * call the BulletSim system.
- */
-/* Revised Aug, Sept 2009 by Kitto Flora. ODEDynamics.cs replaces
- * ODEVehicleSettings.cs. It and ODEPrim.cs are re-organised:
- * ODEPrim.cs contains methods dealing with Prim editing, Prim
- * characteristics and Kinetic motion.
- * ODEDynamics.cs contains methods dealing with Prim Physical motion
- * (dynamics) and the associated settings. Old Linear and angular
- * motors for dynamic motion have been replace with  MoveLinear()
- * and MoveAngular(); 'Physical' is used only to switch ODE dynamic
- * simualtion on/off; VEHICAL_TYPE_NONE/VEHICAL_TYPE_<other> is to
- * switch between 'VEHICLE' parameter use and general dynamics
- * settings use.
+ * The quotations from http://wiki.secondlife.com/wiki/Linden_Vehicle_Tutorial
+ * are Copyright (c) 2009 Linden Research, Inc and are used under their license
+ * of Creative Commons Attribution-Share Alike 3.0
+ * (http://creativecommons.org/licenses/by-sa/3.0/).
  */
 
 using System;
 using System.Collections.Generic;
 using System.Reflection;
 using System.Runtime.InteropServices;
-using log4net;
 using OpenMetaverse;
-using OpenSim.Framework;
 using OpenSim.Region.Physics.Manager;
 
 namespace OpenSim.Region.Physics.BulletSPlugin
@@ -80,10 +67,10 @@ namespace OpenSim.Region.Physics.BulletSPlugin
         private Quaternion m_referenceFrame = Quaternion.Identity;
 
         // Linear properties
+        private BSVMotor m_linearMotor = new BSVMotor("LinearMotor");
         private Vector3 m_linearMotorDirection = Vector3.Zero;          // velocity requested by LSL, decayed by time
         private Vector3 m_linearMotorOffset = Vector3.Zero;             // the point of force can be offset from the center
         private Vector3 m_linearMotorDirectionLASTSET = Vector3.Zero;   // velocity requested by LSL
-        private Vector3 m_newVelocity = Vector3.Zero;                   // velocity computed to be applied to body
         private Vector3 m_linearFrictionTimescale = Vector3.Zero;
         private float m_linearMotorDecayTimescale = 0;
         private float m_linearMotorTimescale = 0;
@@ -93,16 +80,18 @@ namespace OpenSim.Region.Physics.BulletSPlugin
         // private Vector3 m_linearMotorOffset = Vector3.Zero;
 
         //Angular properties
+        private BSVMotor m_angularMotor = new BSVMotor("AngularMotor");
         private Vector3 m_angularMotorDirection = Vector3.Zero;         // angular velocity requested by LSL motor
         // private int m_angularMotorApply = 0;                            // application frame counter
         private Vector3 m_angularMotorVelocity = Vector3.Zero;          // current angular motor velocity
         private float m_angularMotorTimescale = 0;                      // motor angular velocity ramp up rate
         private float m_angularMotorDecayTimescale = 0;                 // motor angular velocity decay rate
         private Vector3 m_angularFrictionTimescale = Vector3.Zero;      // body angular velocity  decay rate
-        private Vector3 m_lastAngularVelocity = Vector3.Zero;           // what was last applied to body
+        private Vector3 m_lastAngularVelocity = Vector3.Zero;
         private Vector3 m_lastVertAttractor = Vector3.Zero;             // what VA was last applied to body
 
         //Deflection properties
+        private BSVMotor m_angularDeflectionMotor = new BSVMotor("AngularDeflection");
         private float m_angularDeflectionEfficiency = 0;
         private float m_angularDeflectionTimescale = 0;
         private float m_linearDeflectionEfficiency = 0;
@@ -114,6 +103,7 @@ namespace OpenSim.Region.Physics.BulletSPlugin
         private float m_bankingTimescale = 0;
 
         //Hover and Buoyancy properties
+        private BSVMotor m_hoverMotor = new BSVMotor("Hover");
         private float m_VhoverHeight = 0f;
         private float m_VhoverEfficiency = 0f;
         private float m_VhoverTimescale = 0f;
@@ -124,8 +114,15 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                     // Therefore only m_VehicleBuoyancy=1 (0g) will use the script-requested .Z velocity.
 
         //Attractor properties
-        private float m_verticalAttractionEfficiency = 1.0f;        // damped
-        private float m_verticalAttractionTimescale = 500f;         // Timescale > 300  means no vert attractor.
+        private BSVMotor m_verticalAttractionMotor = new BSVMotor("VerticalAttraction");
+        private float m_verticalAttractionEfficiency = 1.0f; // damped
+        private float m_verticalAttractionCutoff = 500f;     // per the documentation
+        // Timescale > cutoff  means no vert attractor.
+        private float m_verticalAttractionTimescale = 510f;
+
+        // Just some recomputed constants:
+        static readonly float PIOverFour = ((float)Math.PI) / 4f;
+        static readonly float PIOverTwo = ((float)Math.PI) / 2f;
 
         public BSDynamics(BSScene myScene, BSPrim myPrim)
         {
@@ -137,7 +134,7 @@ namespace OpenSim.Region.Physics.BulletSPlugin
         // Return 'true' if this vehicle is doing vehicle things
         public bool IsActive
         {
-            get { return Type != Vehicle.TYPE_NONE; }
+            get { return Type != Vehicle.TYPE_NONE && Prim.IsPhysical; }
         }
 
         internal void ProcessFloatVehicleParam(Vehicle pParam, float pValue)
@@ -152,13 +149,15 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                     m_angularDeflectionTimescale = Math.Max(pValue, 0.01f);
                     break;
                 case Vehicle.ANGULAR_MOTOR_DECAY_TIMESCALE:
-                    m_angularMotorDecayTimescale = Math.Max(pValue, 0.01f);
+                    m_angularMotorDecayTimescale = ClampInRange(0.01f, pValue, 120);
+                    m_angularMotor.TargetValueDecayTimeScale = m_angularMotorDecayTimescale;
                     break;
                 case Vehicle.ANGULAR_MOTOR_TIMESCALE:
                     m_angularMotorTimescale = Math.Max(pValue, 0.01f);
+                    m_angularMotor.TimeScale = m_angularMotorTimescale;
                     break;
                 case Vehicle.BANKING_EFFICIENCY:
-                    m_bankingEfficiency = Math.Max(-1f, Math.Min(pValue, 1f));
+                    m_bankingEfficiency = ClampInRange(-1f, pValue, 1f);
                     break;
                 case Vehicle.BANKING_MIX:
                     m_bankingMix = Math.Max(pValue, 0.01f);
@@ -167,10 +166,10 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                     m_bankingTimescale = Math.Max(pValue, 0.01f);
                     break;
                 case Vehicle.BUOYANCY:
-                    m_VehicleBuoyancy = Math.Max(-1f, Math.Min(pValue, 1f));
+                    m_VehicleBuoyancy = ClampInRange(-1f, pValue, 1f);
                     break;
                 case Vehicle.HOVER_EFFICIENCY:
-                    m_VhoverEfficiency = Math.Max(0f, Math.Min(pValue, 1f));
+                    m_VhoverEfficiency = ClampInRange(0f, pValue, 1f);
                     break;
                 case Vehicle.HOVER_HEIGHT:
                     m_VhoverHeight = pValue;
@@ -185,33 +184,40 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                     m_linearDeflectionTimescale = Math.Max(pValue, 0.01f);
                     break;
                 case Vehicle.LINEAR_MOTOR_DECAY_TIMESCALE:
-                    m_linearMotorDecayTimescale = Math.Max(pValue, 0.01f);
+                    m_linearMotorDecayTimescale = ClampInRange(0.01f, pValue, 120);
+                    m_linearMotor.TargetValueDecayTimeScale = m_linearMotorDecayTimescale;
                     break;
                 case Vehicle.LINEAR_MOTOR_TIMESCALE:
                     m_linearMotorTimescale = Math.Max(pValue, 0.01f);
+                    m_linearMotor.TimeScale = m_linearMotorTimescale;
                     break;
                 case Vehicle.VERTICAL_ATTRACTION_EFFICIENCY:
-                    m_verticalAttractionEfficiency = Math.Max(0.1f, Math.Min(pValue, 1f));
+                    m_verticalAttractionEfficiency = ClampInRange(0.1f, pValue, 1f);
+                    m_verticalAttractionMotor.Efficiency = m_verticalAttractionEfficiency;
                     break;
                 case Vehicle.VERTICAL_ATTRACTION_TIMESCALE:
                     m_verticalAttractionTimescale = Math.Max(pValue, 0.01f);
+                    m_verticalAttractionMotor.TimeScale = m_verticalAttractionTimescale;
                     break;
 
                 // These are vector properties but the engine lets you use a single float value to
                 // set all of the components to the same value
                 case Vehicle.ANGULAR_FRICTION_TIMESCALE:
                     m_angularFrictionTimescale = new Vector3(pValue, pValue, pValue);
+                    m_angularMotor.FrictionTimescale = m_angularFrictionTimescale;
                     break;
                 case Vehicle.ANGULAR_MOTOR_DIRECTION:
                     m_angularMotorDirection = new Vector3(pValue, pValue, pValue);
-                    // m_angularMotorApply = 100;
+                    m_angularMotor.SetTarget(m_angularMotorDirection);
                     break;
                 case Vehicle.LINEAR_FRICTION_TIMESCALE:
                     m_linearFrictionTimescale = new Vector3(pValue, pValue, pValue);
+                    m_linearMotor.FrictionTimescale = m_linearFrictionTimescale;
                     break;
                 case Vehicle.LINEAR_MOTOR_DIRECTION:
                     m_linearMotorDirection = new Vector3(pValue, pValue, pValue);
                     m_linearMotorDirectionLASTSET = new Vector3(pValue, pValue, pValue);
+                    m_linearMotor.SetTarget(m_linearMotorDirection);
                     break;
                 case Vehicle.LINEAR_MOTOR_OFFSET:
                     m_linearMotorOffset = new Vector3(pValue, pValue, pValue);
@@ -227,21 +233,24 @@ namespace OpenSim.Region.Physics.BulletSPlugin
             {
                 case Vehicle.ANGULAR_FRICTION_TIMESCALE:
                     m_angularFrictionTimescale = new Vector3(pValue.X, pValue.Y, pValue.Z);
+                    m_angularMotor.FrictionTimescale = m_angularFrictionTimescale;
                     break;
                 case Vehicle.ANGULAR_MOTOR_DIRECTION:
                     // Limit requested angular speed to 2 rps= 4 pi rads/sec
-                    pValue.X = Math.Max(-12.56f, Math.Min(pValue.X, 12.56f));
-                    pValue.Y = Math.Max(-12.56f, Math.Min(pValue.Y, 12.56f));
-                    pValue.Z = Math.Max(-12.56f, Math.Min(pValue.Z, 12.56f));
+                    pValue.X = ClampInRange(-12.56f, pValue.X, 12.56f);
+                    pValue.Y = ClampInRange(-12.56f, pValue.Y, 12.56f);
+                    pValue.Z = ClampInRange(-12.56f, pValue.Z, 12.56f);
                     m_angularMotorDirection = new Vector3(pValue.X, pValue.Y, pValue.Z);
-                    // m_angularMotorApply = 100;
+                    m_angularMotor.SetTarget(m_angularMotorDirection);
                     break;
                 case Vehicle.LINEAR_FRICTION_TIMESCALE:
                     m_linearFrictionTimescale = new Vector3(pValue.X, pValue.Y, pValue.Z);
+                    m_linearMotor.FrictionTimescale = m_linearFrictionTimescale;
                     break;
                 case Vehicle.LINEAR_MOTOR_DIRECTION:
                     m_linearMotorDirection = new Vector3(pValue.X, pValue.Y, pValue.Z);
                     m_linearMotorDirectionLASTSET = new Vector3(pValue.X, pValue.Y, pValue.Z);
+                    m_linearMotor.SetTarget(m_linearMotorDirection);
                     break;
                 case Vehicle.LINEAR_MOTOR_OFFSET:
                     m_linearMotorOffset = new Vector3(pValue.X, pValue.Y, pValue.Z);
@@ -303,7 +312,7 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                     m_VhoverEfficiency = 0;
                     m_VhoverTimescale = 0;
                     m_VehicleBuoyancy = 0;
-                    
+
                     m_linearDeflectionEfficiency = 1;
                     m_linearDeflectionTimescale = 1;
 
@@ -319,6 +328,7 @@ namespace OpenSim.Region.Physics.BulletSPlugin
 
                     m_referenceFrame = Quaternion.Identity;
                     m_flags = (VehicleFlag)0;
+
                     break;
 
                 case Vehicle.TYPE_SLED:
@@ -351,10 +361,14 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                     m_bankingMix = 1;
 
                     m_referenceFrame = Quaternion.Identity;
-                    m_flags |= (VehicleFlag.NO_DEFLECTION_UP | VehicleFlag.LIMIT_ROLL_ONLY | VehicleFlag.LIMIT_MOTOR_UP);
-                    m_flags &=
-                         ~(VehicleFlag.HOVER_WATER_ONLY | VehicleFlag.HOVER_TERRAIN_ONLY |
-                           VehicleFlag.HOVER_GLOBAL_HEIGHT | VehicleFlag.HOVER_UP_ONLY);
+                    m_flags &= ~(VehicleFlag.HOVER_WATER_ONLY
+                                | VehicleFlag.HOVER_TERRAIN_ONLY
+                                | VehicleFlag.HOVER_GLOBAL_HEIGHT
+                                | VehicleFlag.HOVER_UP_ONLY);
+                    m_flags |= (VehicleFlag.NO_DEFLECTION_UP
+                            | VehicleFlag.LIMIT_ROLL_ONLY
+                            | VehicleFlag.LIMIT_MOTOR_UP);
+
                     break;
                 case Vehicle.TYPE_CAR:
                     m_linearMotorDirection = Vector3.Zero;
@@ -498,6 +512,7 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                     m_bankingEfficiency = 0;
                     m_bankingMix = 0.7f;
                     m_bankingTimescale = 5;
+
                     m_referenceFrame = Quaternion.Identity;
 
                     m_referenceFrame = Quaternion.Identity;
@@ -510,6 +525,26 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                                     | VehicleFlag.HOVER_GLOBAL_HEIGHT);
                     break;
             }
+
+            // Update any physical parameters based on this type.
+            Refresh();
+
+            m_linearMotor = new BSVMotor("LinearMotor", m_linearMotorTimescale,
+                                m_linearMotorDecayTimescale, m_linearFrictionTimescale,
+                                1f);
+            m_linearMotor.PhysicsScene = PhysicsScene;  // DEBUG DEBUG DEBUG (enables detail logging)
+
+            m_angularMotor = new BSVMotor("AngularMotor", m_angularMotorTimescale,
+                                m_angularMotorDecayTimescale, m_angularFrictionTimescale,
+                                1f);
+            m_angularMotor.PhysicsScene = PhysicsScene;  // DEBUG DEBUG DEBUG (enables detail logging)
+
+            m_verticalAttractionMotor = new BSVMotor("VerticalAttraction", m_verticalAttractionTimescale,
+                                BSMotor.Infinite, BSMotor.InfiniteVector,
+                                m_verticalAttractionEfficiency);
+            // Z goes away and we keep X and Y
+            m_verticalAttractionMotor.FrictionTimescale = new Vector3(BSMotor.Infinite, BSMotor.Infinite, 0.1f);
+            m_verticalAttractionMotor.PhysicsScene = PhysicsScene;  // DEBUG DEBUG DEBUG (enables detail logging)
         }
 
         // Some of the properties of this prim may have changed.
@@ -518,13 +553,32 @@ namespace OpenSim.Region.Physics.BulletSPlugin
         {
             if (IsActive)
             {
-                // Friction effects are handled by this vehicle code
-                BulletSimAPI.SetFriction2(Prim.PhysBody.ptr, 0f);
-                BulletSimAPI.SetHitFraction2(Prim.PhysBody.ptr, 0f);
+                // Remember the mass so we don't have to fetch it every step
+                m_vehicleMass = Prim.Linkset.LinksetMass;
 
-                // BulletSimAPI.SetAngularDamping2(Prim.PhysBody.ptr, 0.8f);
+                // Friction affects are handled by this vehicle code
+                float friction = 0f;
+                BulletSimAPI.SetFriction2(Prim.PhysBody.ptr, friction);
 
-                VDetailLog("{0},BSDynamics.Refresh,zeroingFriction and adding damping", Prim.LocalID);
+                // Moderate angular movement introduced by Bullet.
+                // TODO: possibly set AngularFactor and LinearFactor for the type of vehicle.
+                //     Maybe compute linear and angular factor and damping from params.
+                float angularDamping = PhysicsScene.Params.vehicleAngularDamping;
+                BulletSimAPI.SetAngularDamping2(Prim.PhysBody.ptr, angularDamping);
+
+                // Vehicles report collision events so we know when it's on the ground
+                BulletSimAPI.AddToCollisionFlags2(Prim.PhysBody.ptr, CollisionFlags.BS_VEHICLE_COLLISIONS);
+
+                Vector3 localInertia = BulletSimAPI.CalculateLocalInertia2(Prim.PhysShape.ptr, m_vehicleMass);
+                BulletSimAPI.SetMassProps2(Prim.PhysBody.ptr, m_vehicleMass, localInertia);
+                BulletSimAPI.UpdateInertiaTensor2(Prim.PhysBody.ptr);
+
+                VDetailLog("{0},BSDynamics.Refresh,mass={1},frict={2},inert={3},aDamp={4}",
+                                Prim.LocalID, m_vehicleMass, friction, localInertia, angularDamping);
+            }
+            else
+            {
+                BulletSimAPI.RemoveFromCollisionFlags2(Prim.PhysBody.ptr, CollisionFlags.BS_VEHICLE_COLLISIONS);
             }
         }
 
@@ -546,116 +600,317 @@ namespace OpenSim.Region.Physics.BulletSPlugin
             Refresh();
         }
 
+        #region Known vehicle value functions
+        // Vehicle physical parameters that we buffer from constant getting and setting.
+        // The "m_known*" values are unknown until they are fetched and the m_knownHas flag is set.
+        //      Changing is remembered and the parameter is stored back into the physics engine only if updated.
+        //      This does two things: 1) saves continuious calls into unmanaged code, and
+        //      2) signals when a physics property update must happen back to the simulator
+        //      to update values modified for the vehicle.
+        private int m_knownChanged;
+        private int m_knownHas;
+        private float m_knownTerrainHeight;
+        private float m_knownWaterLevel;
+        private Vector3 m_knownPosition;
+        private Vector3 m_knownVelocity;
+        private Vector3 m_knownForce;
+        private Quaternion m_knownOrientation;
+        private Vector3 m_knownRotationalVelocity;
+        private Vector3 m_knownRotationalForce;
+        private Vector3 m_knownForwardVelocity;    // vehicle relative forward speed
+
+        private const int m_knownChangedPosition           = 1 << 0;
+        private const int m_knownChangedVelocity           = 1 << 1;
+        private const int m_knownChangedForce              = 1 << 2;
+        private const int m_knownChangedOrientation        = 1 << 3;
+        private const int m_knownChangedRotationalVelocity = 1 << 4;
+        private const int m_knownChangedRotationalForce    = 1 << 5;
+        private const int m_knownChangedTerrainHeight      = 1 << 6;
+        private const int m_knownChangedWaterLevel         = 1 << 7;
+        private const int m_knownChangedForwardVelocity    = 1 << 8;
+
+        private void ForgetKnownVehicleProperties()
+        {
+            m_knownHas = 0;
+            m_knownChanged = 0;
+        }
+        private void PushKnownChanged()
+        {
+            if (m_knownChanged != 0)
+            {
+                if ((m_knownChanged & m_knownChangedPosition) != 0)
+                    Prim.ForcePosition = VehiclePosition;
+                if ((m_knownChanged & m_knownChangedOrientation) != 0)
+                    Prim.ForceOrientation = VehicleOrientation;
+                if ((m_knownChanged & m_knownChangedVelocity) != 0)
+                {
+                    Prim.ForceVelocity = VehicleVelocity;
+                    BulletSimAPI.SetInterpolationLinearVelocity2(Prim.PhysBody.ptr, VehicleVelocity);
+                }
+                if ((m_knownChanged & m_knownChangedForce) != 0)
+                    Prim.AddForce((Vector3)m_knownForce, false, true);
+
+                if ((m_knownChanged & m_knownChangedRotationalVelocity) != 0)
+                {
+                    Prim.ForceRotationalVelocity = VehicleRotationalVelocity;
+                    // Fake out Bullet by making it think the velocity is the same as last time.
+                    BulletSimAPI.SetInterpolationAngularVelocity2(Prim.PhysBody.ptr, VehicleRotationalVelocity);
+                }
+                if ((m_knownChanged & m_knownChangedRotationalForce) != 0)
+                    Prim.AddAngularForce((Vector3)m_knownRotationalForce, false, true);
+
+                // If we set one of the values (ie, the physics engine didn't do it) we must force
+                //      an UpdateProperties event to send the changes up to the simulator.
+                BulletSimAPI.PushUpdate2(Prim.PhysBody.ptr);
+            }
+            m_knownChanged = 0;
+        }
+
+        // Since the computation of terrain height can be a little involved, this routine
+        //    is used ot fetch the height only once for each vehicle simulation step.
+        private float GetTerrainHeight(Vector3 pos)
+        {
+            if ((m_knownHas & m_knownChangedTerrainHeight) == 0)
+            {
+                m_knownTerrainHeight = Prim.PhysicsScene.TerrainManager.GetTerrainHeightAtXYZ(pos);
+                m_knownHas |= m_knownChangedTerrainHeight;
+            }
+            return m_knownTerrainHeight;
+        }
+
+        // Since the computation of water level can be a little involved, this routine
+        //    is used ot fetch the level only once for each vehicle simulation step.
+        private float GetWaterLevel(Vector3 pos)
+        {
+            if ((m_knownHas & m_knownChangedWaterLevel) == 0)
+            {
+                m_knownWaterLevel = Prim.PhysicsScene.TerrainManager.GetWaterLevelAtXYZ(pos);
+                m_knownHas |= m_knownChangedWaterLevel;
+            }
+            return (float)m_knownWaterLevel;
+        }
+
+        private Vector3 VehiclePosition
+        {
+            get
+            {
+                if ((m_knownHas & m_knownChangedPosition) == 0)
+                {
+                    m_knownPosition = Prim.ForcePosition;
+                    m_knownHas |= m_knownChangedPosition;
+                }
+                return (Vector3)m_knownPosition;
+            }
+            set
+            {
+                m_knownPosition = value;
+                m_knownChanged |= m_knownChangedPosition;
+            }
+        }
+
+        private Quaternion VehicleOrientation
+        {
+            get
+            {
+                if ((m_knownHas & m_knownChangedOrientation) == 0)
+                {
+                    m_knownOrientation = Prim.ForceOrientation;
+                    m_knownHas |= m_knownChangedOrientation;
+                }
+                return (Quaternion)m_knownOrientation;
+            }
+            set
+            {
+                m_knownOrientation = value;
+                m_knownChanged |= m_knownChangedOrientation;
+            }
+        }
+
+        private Vector3 VehicleVelocity
+        {
+            get
+            {
+                if ((m_knownHas & m_knownChangedVelocity) == 0)
+                {
+                    m_knownVelocity = Prim.ForceVelocity;
+                    m_knownHas |= m_knownChangedVelocity;
+                }
+                return (Vector3)m_knownVelocity;
+            }
+            set
+            {
+                m_knownVelocity = value;
+                m_knownChanged |= m_knownChangedVelocity;
+            }
+        }
+
+        private void VehicleAddForce(Vector3 aForce)
+        {
+            m_knownForce += aForce;
+            m_knownChanged |= m_knownChangedForce;
+        }
+
+        private Vector3 VehicleRotationalVelocity
+        {
+            get
+            {
+                if ((m_knownHas & m_knownChangedRotationalVelocity) == 0)
+                {
+                    m_knownRotationalVelocity = Prim.ForceRotationalVelocity;
+                    m_knownHas |= m_knownChangedRotationalVelocity;
+                }
+                return (Vector3)m_knownRotationalVelocity;
+            }
+            set
+            {
+                m_knownRotationalVelocity = value;
+                m_knownChanged |= m_knownChangedRotationalVelocity;
+            }
+        }
+        private void VehicleAddAngularForce(Vector3 aForce)
+        {
+            m_knownRotationalForce += aForce;
+            m_knownChanged |= m_knownChangedRotationalForce;
+        }
+        // Vehicle relative forward velocity
+        private Vector3 VehicleForwardVelocity
+        {
+            get
+            {
+                if ((m_knownHas & m_knownChangedForwardVelocity) == 0)
+                {
+                    m_knownForwardVelocity = VehicleVelocity * Quaternion.Inverse(Quaternion.Normalize(VehicleOrientation));
+                    m_knownHas |= m_knownChangedForwardVelocity;
+                }
+                return (Vector3)m_knownForwardVelocity;
+            }
+        }
+        private float VehicleForwardSpeed
+        {
+            get
+            {
+                return VehicleForwardVelocity.X;
+            }
+        }
+
+        #endregion // Known vehicle value functions
+
         // One step of the vehicle properties for the next 'pTimestep' seconds.
         internal void Step(float pTimestep)
         {
             if (!IsActive) return;
 
-            // DEBUG
-            // Because Bullet does apply forces to the vehicle, our last computed
-            //     linear and angular velocities are not what is happening now.
-            // Vector3 externalAngularVelocity = Prim.ForceRotationalVelocity - m_lastAngularVelocity;
-            // m_lastAngularVelocity += (externalAngularVelocity * 0.5f) * pTimestep;
-            // m_lastAngularVelocity = Prim.ForceRotationalVelocity;   // DEBUG: account for what Bullet did last time
-            // m_lastLinearVelocityVector = Prim.ForceVelocity * Quaternion.Inverse(Prim.ForceOrientation);        // DEBUG:
-            // END DEBUG
-
-            m_vehicleMass = Prim.Linkset.LinksetMass;
+            ForgetKnownVehicleProperties();
 
             MoveLinear(pTimestep);
-            // Commented out for debug
             MoveAngular(pTimestep);
-            // Prim.ApplyTorqueImpulse(-Prim.RotationalVelocity * m_vehicleMass, false);    // DEBUG DEBUG
-            // Prim.ForceRotationalVelocity = -Prim.RotationalVelocity;    // DEBUG DEBUG
 
             LimitRotation(pTimestep);
 
             // remember the position so next step we can limit absolute movement effects
-            m_lastPositionVector = Prim.ForcePosition;
-
-            VDetailLog("{0},BSDynamics.Step,frict={1},grav={2},inertia={3},mass={4}",        // DEBUG DEBUG
-                                    Prim.LocalID, 
-                                    BulletSimAPI.GetFriction2(Prim.PhysBody.ptr),
-                                    BulletSimAPI.GetGravity2(Prim.PhysBody.ptr),
-                                    Prim.Inertia,
-                                    m_vehicleMass
-                                    );
+            m_lastPositionVector = VehiclePosition;
+
+            // If we forced the changing of some vehicle parameters, update the values and
+            //      for the physics engine to note the changes so an UpdateProperties event will happen.
+            PushKnownChanged();
+
             VDetailLog("{0},BSDynamics.Step,done,pos={1},force={2},velocity={3},angvel={4}",
-                    Prim.LocalID, Prim.ForcePosition, Prim.Force, Prim.ForceVelocity, Prim.RotationalVelocity);
-        }// end Step
+                    Prim.LocalID, VehiclePosition, Prim.Force, VehicleVelocity, VehicleRotationalVelocity);
+        }
 
-        // Apply the effect of the linear motor.
-        // Also does hover and float.
+        // Apply the effect of the linear motor and other linear motions (like hover and float).
         private void MoveLinear(float pTimestep)
         {
-            // m_linearMotorDirection is the target direction we are moving relative to the vehicle coordinates
-            // m_lastLinearVelocityVector is the current speed we are moving in that direction
-            if (m_linearMotorDirection.LengthSquared() > 0.001f)
-            {
-                Vector3 origDir = m_linearMotorDirection;       // DEBUG
-                Vector3 origVel = m_lastLinearVelocityVector;   // DEBUG
-                // DEBUG: the vehicle velocity rotated to be relative to vehicle coordinates for comparison
-                Vector3 vehicleVelocity = Prim.ForceVelocity * Quaternion.Inverse(Prim.ForceOrientation);   // DEBUG
+            Vector3 linearMotorContribution = m_linearMotor.Step(pTimestep);
 
-                // Add (desiredVelocity - lastAppliedVelocity) / howLongItShouldTakeToComplete
-                Vector3 addAmount = (m_linearMotorDirection - m_lastLinearVelocityVector)/(m_linearMotorTimescale) * pTimestep;
-                m_lastLinearVelocityVector += addAmount;
+            // The movement computed in the linear motor is relative to the vehicle
+            //     coordinates. Rotate the movement to world coordinates.
+            linearMotorContribution *= VehicleOrientation;
 
-                float decayFactor = (1.0f / m_linearMotorDecayTimescale) * pTimestep;
-                m_linearMotorDirection *= (1f - decayFactor);
+            // ==================================================================
+            // Buoyancy: force to overcome gravity.
+            // m_VehicleBuoyancy: -1=2g; 0=1g; 1=0g;
+            // So, if zero, don't change anything (let gravity happen). If one, negate the effect of gravity.
+            Vector3 buoyancyContribution =  Prim.PhysicsScene.DefaultGravity * m_VehicleBuoyancy;
 
-                // Rotate new object velocity from vehicle relative to world coordinates
-                m_newVelocity = m_lastLinearVelocityVector * Prim.ForceOrientation;
+            Vector3 terrainHeightContribution = ComputeLinearTerrainHeightCorrection(pTimestep);
 
-                // Apply friction for next time
-                Vector3 frictionFactor = (Vector3.One / m_linearFrictionTimescale) * pTimestep;
-                m_lastLinearVelocityVector *= (Vector3.One - frictionFactor);
+            Vector3 hoverContribution = ComputeLinearHover(pTimestep);
 
-                VDetailLog("{0},MoveLinear,nonZero,origlmDir={1},origlvVel={2},vehVel={3},add={4},decay={5},frict={6},lmDir={7},lvVec={8},newVel={9}",
-                                Prim.LocalID, origDir, origVel, vehicleVelocity, addAmount, decayFactor, frictionFactor, 
-                                m_linearMotorDirection, m_lastLinearVelocityVector, m_newVelocity);
-            }
-            else
-            {
-                // if what remains of direction is very small, zero it.
-                m_linearMotorDirection = Vector3.Zero;
-                m_lastLinearVelocityVector = Vector3.Zero;
-                m_newVelocity = Vector3.Zero;
+            ComputeLinearBlockingEndPoint(pTimestep);
+
+            Vector3 limitMotorUpContribution = ComputeLinearMotorUp(pTimestep);
+
+            // ==================================================================
+            Vector3 newVelocity = linearMotorContribution
+                            + terrainHeightContribution
+                            + hoverContribution
+                            + limitMotorUpContribution;
+
+            Vector3 newForce = buoyancyContribution;
 
-                VDetailLog("{0},MoveLinear,zeroed", Prim.LocalID);
+            // If not changing some axis, reduce out velocity
+            if ((m_flags & (VehicleFlag.NO_X)) != 0)
+                newVelocity.X = 0;
+            if ((m_flags & (VehicleFlag.NO_Y)) != 0)
+                newVelocity.Y = 0;
+            if ((m_flags & (VehicleFlag.NO_Z)) != 0)
+                newVelocity.Z = 0;
+
+            // ==================================================================
+            // Clamp high or low velocities
+            float newVelocityLengthSq = newVelocity.LengthSquared();
+            if (newVelocityLengthSq > 1000f)
+            {
+                newVelocity /= newVelocity.Length();
+                newVelocity *= 1000f;
             }
+            else if (newVelocityLengthSq < 0.001f)
+                newVelocity = Vector3.Zero;
 
-            // m_newVelocity is velocity computed from linear motor in world coordinates
+            // ==================================================================
+            // Stuff new linear velocity into the vehicle.
+            // Since the velocity is just being set, it is not scaled by pTimeStep. Bullet will do that for us.
+            VehicleVelocity = newVelocity;
 
-            // Gravity and Buoyancy
-            // There is some gravity, make a gravity force vector that is applied after object velocity.
-            // m_VehicleBuoyancy: -1=2g; 0=1g; 1=0g;
-            Vector3 grav = Prim.PhysicsScene.DefaultGravity * (1f - m_VehicleBuoyancy);
+            // Other linear forces are applied as forces.
+            Vector3 totalDownForce = newForce * m_vehicleMass;
+            if (!totalDownForce.ApproxEquals(Vector3.Zero, 0.01f))
+            {
+                VehicleAddForce(totalDownForce);
+            }
 
-            /*
-             * RA: Not sure why one would do this unless we are hoping external forces are doing gravity, ...
-            // Preserve the current Z velocity
-            Vector3 vel_now = m_prim.Velocity;
-            m_dir.Z = vel_now.Z;        // Preserve the accumulated falling velocity
-             */
+            VDetailLog("{0},  MoveLinear,done,newVel={1},totDown={2},IsColliding={3}",
+                                Prim.LocalID, newVelocity, totalDownForce, Prim.IsColliding);
+            VDetailLog("{0},  MoveLinear,done,linContrib={1},terrContrib={2},hoverContrib={3},limitContrib={4},buoyContrib={5}",
+                                Prim.LocalID,
+                                linearMotorContribution, terrainHeightContribution, hoverContribution, 
+                                limitMotorUpContribution, buoyancyContribution
+            );
 
-            Vector3 pos = Prim.ForcePosition;
-//            Vector3 accel = new Vector3(-(m_dir.X - m_lastLinearVelocityVector.X / 0.1f), -(m_dir.Y - m_lastLinearVelocityVector.Y / 0.1f), m_dir.Z - m_lastLinearVelocityVector.Z / 0.1f);
+        } // end MoveLinear()
 
+        public Vector3 ComputeLinearTerrainHeightCorrection(float pTimestep)
+        {
+            Vector3 ret = Vector3.Zero;
             // If below the terrain, move us above the ground a little.
-            float terrainHeight = Prim.PhysicsScene.TerrainManager.GetTerrainHeightAtXYZ(pos);
-            // Taking the rotated size doesn't work here because m_prim.Size is the size of the root prim and not the linkset.
-            //     TODO: Add a m_prim.LinkSet.Size similar to m_prim.LinkSet.Mass.
-            // Vector3 rotatedSize = m_prim.Size * m_prim.ForceOrientation;
-            // if (rotatedSize.Z < terrainHeight)
-            if (pos.Z < terrainHeight)
+            // TODO: Consider taking the rotated size of the object or possibly casting a ray.
+            if (VehiclePosition.Z < GetTerrainHeight(VehiclePosition))
             {
-                pos.Z = terrainHeight + 2;
-                Prim.ForcePosition = pos;
-                VDetailLog("{0},MoveLinear,terrainHeight,terrainHeight={1},pos={2}", Prim.LocalID, terrainHeight, pos);
+                // TODO: correct position by applying force rather than forcing position.
+                Vector3 newPosition = VehiclePosition;
+                newPosition.Z = GetTerrainHeight(VehiclePosition) + 1f;
+                VehiclePosition = newPosition;
+                VDetailLog("{0},  MoveLinear,terrainHeight,terrainHeight={1},pos={2}",
+                        Prim.LocalID, GetTerrainHeight(VehiclePosition), VehiclePosition);
             }
+            return ret;
+        }
+
+        public Vector3 ComputeLinearHover(float pTimestep)
+        {
+            Vector3 ret = Vector3.Zero;
 
-            // Check if hovering
             // m_VhoverEfficiency: 0=bouncy, 1=totally damped
             // m_VhoverTimescale: time to achieve height
             if ((m_flags & (VehicleFlag.HOVER_WATER_ONLY | VehicleFlag.HOVER_TERRAIN_ONLY | VehicleFlag.HOVER_GLOBAL_HEIGHT)) != 0)
@@ -663,11 +918,11 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                 // We should hover, get the target height
                 if ((m_flags & VehicleFlag.HOVER_WATER_ONLY) != 0)
                 {
-                    m_VhoverTargetHeight = Prim.PhysicsScene.GetWaterLevelAtXYZ(pos) + m_VhoverHeight;
+                    m_VhoverTargetHeight = GetWaterLevel(VehiclePosition) + m_VhoverHeight;
                 }
                 if ((m_flags & VehicleFlag.HOVER_TERRAIN_ONLY) != 0)
                 {
-                    m_VhoverTargetHeight = terrainHeight + m_VhoverHeight;
+                    m_VhoverTargetHeight = GetTerrainHeight(VehiclePosition) + m_VhoverHeight;
                 }
                 if ((m_flags & VehicleFlag.HOVER_GLOBAL_HEIGHT) != 0)
                 {
@@ -677,45 +932,47 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                 if ((m_flags & VehicleFlag.HOVER_UP_ONLY) != 0)
                 {
                     // If body is already heigher, use its height as target height
-                    if (pos.Z > m_VhoverTargetHeight)
-                        m_VhoverTargetHeight = pos.Z;
+                    if (VehiclePosition.Z > m_VhoverTargetHeight)
+                        m_VhoverTargetHeight = VehiclePosition.Z;
                 }
+                
                 if ((m_flags & VehicleFlag.LOCK_HOVER_HEIGHT) != 0)
                 {
-                    if (Math.Abs(pos.Z - m_VhoverTargetHeight) > 0.2f)
+                    if (Math.Abs(VehiclePosition.Z - m_VhoverTargetHeight) > 0.2f)
                     {
+                        Vector3 pos = VehiclePosition;
                         pos.Z = m_VhoverTargetHeight;
-                        Prim.ForcePosition = pos;
+                        VehiclePosition = pos;
                     }
                 }
                 else
                 {
-                    float verticalError = pos.Z - m_VhoverTargetHeight;
-                    // RA: where does the 50 come from?
-                    float verticalCorrectionVelocity = pTimestep * ((verticalError * 50.0f) / m_VhoverTimescale);
-                    // Replace Vertical speed with correction figure if significant
-                    if (Math.Abs(verticalError) > 0.01f)
-                    {
-                        m_newVelocity.Z += verticalCorrectionVelocity;
-                        //KF: m_VhoverEfficiency is not yet implemented
-                    }
-                    else if (verticalError < -0.01)
-                    {
-                        m_newVelocity.Z -= verticalCorrectionVelocity;
-                    }
-                    else
+                    // Error is positive if below the target and negative if above.
+                    float verticalError = m_VhoverTargetHeight - VehiclePosition.Z;
+                    float verticalCorrectionVelocity = verticalError / m_VhoverTimescale;
+
+                    // TODO: implement m_VhoverEfficiency correctly
+                    if (Math.Abs(verticalError) > m_VhoverEfficiency)
                     {
-                        m_newVelocity.Z = 0f;
+                        ret = new Vector3(0f, 0f, verticalCorrectionVelocity);
                     }
                 }
 
-                VDetailLog("{0},MoveLinear,hover,pos={1},dir={2},height={3},target={4}", Prim.LocalID, pos, m_newVelocity, m_VhoverHeight, m_VhoverTargetHeight);
+                VDetailLog("{0},  MoveLinear,hover,pos={1},ret={2},hoverTS={3},height={4},target={5}",
+                                Prim.LocalID, VehiclePosition, ret, m_VhoverTimescale, m_VhoverHeight, m_VhoverTargetHeight);
             }
 
+            return ret;
+        }
+
+        public bool ComputeLinearBlockingEndPoint(float pTimestep)
+        {
+            bool changed = false;
+
+            Vector3 pos = VehiclePosition;
             Vector3 posChange = pos - m_lastPositionVector;
             if (m_BlockingEndPoint != Vector3.Zero)
             {
-                bool changed = false;
                 if (pos.X >= (m_BlockingEndPoint.X - (float)1))
                 {
                     pos.X -= posChange.X + 1;
@@ -743,233 +1000,109 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                 }
                 if (changed)
                 {
-                    Prim.ForcePosition = pos;
-                    VDetailLog("{0},MoveLinear,blockingEndPoint,block={1},origPos={2},pos={3}",
+                    VehiclePosition = pos;
+                    VDetailLog("{0},  MoveLinear,blockingEndPoint,block={1},origPos={2},pos={3}",
                                 Prim.LocalID, m_BlockingEndPoint, posChange, pos);
                 }
             }
+            return changed;
+        }
 
-            #region downForce
-            Vector3 downForce = Vector3.Zero;
+        // From http://wiki.secondlife.com/wiki/LlSetVehicleFlags :
+        //    Prevent ground vehicles from motoring into the sky. This flag has a subtle effect when
+        //    used with conjunction with banking: the strength of the banking will decay when the
+        //    vehicle no longer experiences collisions. The decay timescale is the same as
+        //    VEHICLE_BANKING_TIMESCALE. This is to help prevent ground vehicles from steering
+        //    when they are in mid jump. 
+        // TODO: this code is wrong. Also, what should it do for boats (height from water)?
+        //    This is just using the ground and a general collision check. Should really be using
+        //    a downward raycast to find what is below.
+        public Vector3 ComputeLinearMotorUp(float pTimestep)
+        {
+            Vector3 ret = Vector3.Zero;
+            float distanceAboveGround = 0f;
 
             if ((m_flags & (VehicleFlag.LIMIT_MOTOR_UP)) != 0)
             {
-                // If the vehicle is motoring into the sky, get it going back down.
-                // Is this an angular force or both linear and angular??
-                float distanceAboveGround = pos.Z - terrainHeight;
-                if (distanceAboveGround > 2f)
+                float targetHeight = Type == Vehicle.TYPE_BOAT ? GetWaterLevel(VehiclePosition) : GetTerrainHeight(VehiclePosition);
+                distanceAboveGround = VehiclePosition.Z - targetHeight;
+                // Not colliding if the vehicle is off the ground
+                if (!Prim.IsColliding)
                 {
-                    // downForce = new Vector3(0, 0, (-distanceAboveGround / m_bankingTimescale) * pTimestep);
                     // downForce = new Vector3(0, 0, -distanceAboveGround / m_bankingTimescale);
-                    downForce = new Vector3(0, 0, -distanceAboveGround);
+                    ret = new Vector3(0, 0, -distanceAboveGround);
                 }
-                // TODO: this calculation is all wrong. From the description at
+                // TODO: this calculation is wrong. From the description at
                 //     (http://wiki.secondlife.com/wiki/Category:LSL_Vehicle), the downForce
                 //     has a decay factor. This says this force should
                 //     be computed with a motor.
-                VDetailLog("{0},MoveLinear,limitMotorUp,distAbove={1},downForce={2}", 
-                                    Prim.LocalID, distanceAboveGround, downForce);
-            }
-            #endregion // downForce
-
-            // If not changing some axis, reduce out velocity
-            if ((m_flags & (VehicleFlag.NO_X)) != 0)
-                m_newVelocity.X = 0;
-            if ((m_flags & (VehicleFlag.NO_Y)) != 0)
-                m_newVelocity.Y = 0;
-            if ((m_flags & (VehicleFlag.NO_Z)) != 0)
-                m_newVelocity.Z = 0;
-
-            // Clamp REALLY high or low velocities
-            if (m_newVelocity.LengthSquared() > 1e6f)
-            {
-                m_newVelocity /= m_newVelocity.Length();
-                m_newVelocity *= 1000f;
-            }
-            else if (m_newVelocity.LengthSquared() < 1e-6f)
-                m_newVelocity = Vector3.Zero;
-
-            // Stuff new linear velocity into the vehicle
-            Prim.ForceVelocity = m_newVelocity;
-            // Prim.ApplyForceImpulse((m_newVelocity - Prim.Velocity) * m_vehicleMass, false);    // DEBUG DEBUG
-
-            Vector3 totalDownForce = downForce + grav;
-            if (totalDownForce != Vector3.Zero)
-            {
-                Prim.AddForce(totalDownForce * m_vehicleMass, false);
-                // Prim.ApplyForceImpulse(totalDownForce * m_vehicleMass, false);
+                // TODO: add interaction with banking.
             }
-
-            VDetailLog("{0},MoveLinear,done,lmDir={1},lmVel={2},newVel={3},primVel={4},totalDown={5}",
-                    Prim.LocalID, m_linearMotorDirection, m_lastLinearVelocityVector, m_newVelocity, Prim.Velocity, totalDownForce);
-
-        } // end MoveLinear()
+            VDetailLog("{0},  MoveLinear,limitMotorUp,distAbove={1},colliding={2},ret={3}",
+                                Prim.LocalID, distanceAboveGround, Prim.IsColliding, ret);
+            return ret;
+        }
 
         // =======================================================================
+        // =======================================================================
         // Apply the effect of the angular motor.
+        // The 'contribution' is how much angular correction velocity each function wants.
+        //     All the contributions are added together and the resulting velocity is
+        //     set directly on the vehicle.
         private void MoveAngular(float pTimestep)
         {
-            // m_angularMotorDirection         // angular velocity requested by LSL motor
-            // m_angularMotorApply             // application frame counter
-            // m_angularMotorVelocity          // current angular motor velocity (ramps up and down)
-            // m_angularMotorTimescale         // motor angular velocity ramp up rate
-            // m_angularMotorDecayTimescale    // motor angular velocity decay rate
-            // m_angularFrictionTimescale      // body angular velocity  decay rate
-            // m_lastAngularVelocity           // what was last applied to body
-
-            if (m_angularMotorDirection.LengthSquared() > 0.0001)
-            {
-                Vector3 origVel = m_angularMotorVelocity;
-                Vector3 origDir = m_angularMotorDirection;
-
-                //       new velocity    +=                      error                       /  (  time to get there   / step interval)
-                //                           requested direction   - current vehicle direction
-                m_angularMotorVelocity += (m_angularMotorDirection - m_angularMotorVelocity) /  (m_angularMotorTimescale / pTimestep);
-                // decay requested direction
-                m_angularMotorDirection *= (1.0f - (pTimestep * 1.0f/m_angularMotorDecayTimescale));
-
-                VDetailLog("{0},MoveAngular,angularMotorApply,angTScale={1},timeStep={2},origvel={3},origDir={4},vel={5}",
-                        Prim.LocalID, m_angularMotorTimescale, pTimestep, origVel, origDir, m_angularMotorVelocity);
-            }
-            else
+            // The user wants this many radians per second angular change?
+            Vector3 angularMotorContribution = m_angularMotor.Step(pTimestep);
+
+            // ==================================================================
+            // From http://wiki.secondlife.com/wiki/LlSetVehicleFlags :
+            //    This flag prevents linear deflection parallel to world z-axis. This is useful
+            //    for preventing ground vehicles with large linear deflection, like bumper cars,
+            //    from climbing their linear deflection into the sky. 
+            // That is, NO_DEFLECTION_UP says angular motion should not add any pitch or roll movement
+            if ((m_flags & (VehicleFlag.NO_DEFLECTION_UP)) != 0)
             {
-                m_angularMotorVelocity = Vector3.Zero;
+                angularMotorContribution.X = 0f;
+                angularMotorContribution.Y = 0f;
+                VDetailLog("{0},  MoveAngular,noDeflectionUp,angularMotorContrib={1}", Prim.LocalID, angularMotorContribution);
             }
 
-            #region Vertical attactor
+            Vector3 verticalAttractionContribution = ComputeAngularVerticalAttraction();
 
-            Vector3 vertattr = Vector3.Zero;
-            Vector3 deflection = Vector3.Zero;
-            Vector3 banking = Vector3.Zero;
+            Vector3 deflectionContribution = ComputeAngularDeflection();
 
-            // If vertical attaction timescale is reasonable and we applied an angular force last time...
-            if (m_verticalAttractionTimescale < 300 && m_lastAngularVelocity != Vector3.Zero)
-            {
-                float VAservo = pTimestep * 0.2f / m_verticalAttractionTimescale;
-                if (Prim.IsColliding)
-                    VAservo = pTimestep * 0.05f / (m_verticalAttractionTimescale);
-
-                VAservo *= (m_verticalAttractionEfficiency * m_verticalAttractionEfficiency);
-
-                // Create a vector of the vehicle "up" in world coordinates
-                Vector3 verticalError = Vector3.UnitZ * Prim.ForceOrientation;
-                // verticalError.X and .Y are the World error amounts. They are 0 when there is no
-                //      error (Vehicle Body is 'vertical'), and .Z will be 1. As the body leans to its
-                //      side |.X| will increase to 1 and .Z fall to 0. As body inverts |.X| will fall
-                //      and .Z will go // negative. Similar for tilt and |.Y|. .X and .Y must be
-                //      modulated to prevent a stable inverted body.
-
-                // Error is 0 (no error) to +/- 2 (max error)
-                if (verticalError.Z < 0.0f)
-                {
-                    verticalError.X = 2.0f - verticalError.X;
-                    verticalError.Y = 2.0f - verticalError.Y;
-                }
-                // scale it by VAservo (timestep and timescale)
-                verticalError = verticalError * VAservo;
+            Vector3 bankingContribution = ComputeAngularBanking();
 
-                // As the body rotates around the X axis, then verticalError.Y increases; Rotated around Y
-                //     then .X increases, so change  Body angular velocity  X based on Y, and Y based on X.
-                //     Z is not changed.
-                vertattr.X =    verticalError.Y;
-                vertattr.Y =  - verticalError.X;
-                vertattr.Z = 0f;
+            // ==================================================================
+            m_lastVertAttractor = verticalAttractionContribution;
 
-                // scaling appears better usingsquare-law
-                Vector3 angularVelocity = Prim.ForceRotationalVelocity;
-                float bounce = 1.0f - (m_verticalAttractionEfficiency * m_verticalAttractionEfficiency);
-                vertattr.X += bounce * angularVelocity.X;
-                vertattr.Y += bounce * angularVelocity.Y;
-
-                VDetailLog("{0},MoveAngular,verticalAttraction,VAservo={1},effic={2},verticalError={3},bounce={4},vertattr={5}",
-                            Prim.LocalID, VAservo, m_verticalAttractionEfficiency, verticalError, bounce, vertattr);
-
-            }
-            #endregion // Vertical attactor
+            m_lastAngularVelocity = angularMotorContribution
+                                    + verticalAttractionContribution
+                                    + deflectionContribution
+                                    + bankingContribution;
 
-            #region Deflection
-
-            if (m_angularDeflectionEfficiency != 0)
+            // ==================================================================
+            // Apply the correction velocity.
+            // TODO: Should this be applied as an angular force (torque)?
+            if (!m_lastAngularVelocity.ApproxEquals(Vector3.Zero, 0.01f))
             {
-                // Compute a scaled vector that points in the preferred axis (X direction)
-                Vector3 scaledDefaultDirection =
-                    new Vector3((pTimestep * 10 * (m_angularDeflectionEfficiency / m_angularDeflectionTimescale)), 0, 0);
-                // Adding the current vehicle orientation and reference frame displaces the orientation to the frame.
-                // Rotate the scaled default axix relative to the actual vehicle direction giving where it should point.
-                Vector3 preferredAxisOfMotion = scaledDefaultDirection * Quaternion.Add(Prim.ForceOrientation, m_referenceFrame);
-
-                // Scale by efficiency and timescale
-                deflection = (preferredAxisOfMotion * (m_angularDeflectionEfficiency) / m_angularDeflectionTimescale) * pTimestep;
-
-                VDetailLog("{0},MoveAngular,Deflection,perfAxis={1},deflection={2}", 
-                                        Prim.LocalID, preferredAxisOfMotion, deflection);
-                // This deflection computation is not correct.
-                deflection = Vector3.Zero;
-            }
-
-            #endregion
+                VehicleRotationalVelocity = m_lastAngularVelocity;
 
-            #region Banking
-
-            if (m_bankingEfficiency != 0)
+                VDetailLog("{0},  MoveAngular,done,nonZero,angMotorContrib={1},vertAttrContrib={2},bankContrib={3},deflectContrib={4},totalContrib={5}",
+                                    Prim.LocalID,
+                                    angularMotorContribution, verticalAttractionContribution,
+                                    bankingContribution, deflectionContribution,
+                                    m_lastAngularVelocity
+                                    );
+            }
+            else
             {
-                Vector3 dir = Vector3.One * Prim.ForceOrientation;
-                float mult = (m_bankingMix*m_bankingMix)*-1*(m_bankingMix < 0 ? -1 : 1);
-                    //Changes which way it banks in and out of turns
-
-                //Use the square of the efficiency, as it looks much more how SL banking works
-                float effSquared = (m_bankingEfficiency*m_bankingEfficiency);
-                if (m_bankingEfficiency < 0)
-                    effSquared *= -1; //Keep the negative!
-
-                float mix = Math.Abs(m_bankingMix);
-                if (m_angularMotorVelocity.X == 0)
-                {
-                    /*if (!parent.Orientation.ApproxEquals(this.m_referenceFrame, 0.25f))
-                    {
-                        Vector3 axisAngle;
-                        float angle;
-                        parent.Orientation.GetAxisAngle(out axisAngle, out angle);
-                        Vector3 rotatedVel = parent.Velocity * parent.Orientation;
-                        if ((rotatedVel.X < 0 && axisAngle.Y > 0) || (rotatedVel.X > 0 && axisAngle.Y < 0))
-                            m_angularMotorVelocity.X += (effSquared * (mult * mix)) * (1f) * 10;
-                        else
-                            m_angularMotorVelocity.X += (effSquared * (mult * mix)) * (-1f) * 10;
-                    }*/
-                }
-                else
-                    banking.Z += (effSquared*(mult*mix))*(m_angularMotorVelocity.X) * 4;
-                if (!Prim.IsColliding && Math.Abs(m_angularMotorVelocity.X) > mix)
-                    //If they are colliding, we probably shouldn't shove the prim around... probably
-                {
-                    float angVelZ = m_angularMotorVelocity.X*-1;
-                    /*if(angVelZ > mix)
-                        angVelZ = mix;
-                    else if(angVelZ < -mix)
-                        angVelZ = -mix;*/
-                    //This controls how fast and how far the banking occurs
-                    Vector3 bankingRot = new Vector3(angVelZ*(effSquared*mult), 0, 0);
-                    if (bankingRot.X > 3)
-                        bankingRot.X = 3;
-                    else if (bankingRot.X < -3)
-                        bankingRot.X = -3;
-                    bankingRot *= Prim.ForceOrientation;
-                    banking += bankingRot;
-                }
-                m_angularMotorVelocity.X *= m_bankingEfficiency == 1 ? 0.0f : 1 - m_bankingEfficiency;
-                VDetailLog("{0},MoveAngular,Banking,bEff={1},angMotVel={2},banking={3}", 
-                                Prim.LocalID, m_bankingEfficiency, m_angularMotorVelocity, banking);
+                // The vehicle is not adding anything angular wise.
+                VehicleRotationalVelocity = Vector3.Zero;
+                VDetailLog("{0},  MoveAngular,done,zero", Prim.LocalID);
             }
 
-            #endregion
-
-            m_lastVertAttractor = vertattr;
-
-            // Sum velocities
-            m_lastAngularVelocity = m_angularMotorVelocity + vertattr + banking + deflection;
-
-            #region Linear Motor Offset
-
+            // ==================================================================
             //Offset section
             if (m_linearMotorOffset != Vector3.Zero)
             {
@@ -985,8 +1118,8 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                 //
                 // The torque created is the linear velocity crossed with the offset
 
-                // NOTE: this computation does should be in the linear section
-                //    because there we know the impulse being applied.
+                // TODO: this computation should be in the linear section
+                //    because that is where we know the impulse being applied.
                 Vector3 torqueFromOffset = Vector3.Zero;
                 // torqueFromOffset = Vector3.Cross(m_linearMotorOffset, appliedImpulse);
                 if (float.IsNaN(torqueFromOffset.X))
@@ -995,47 +1128,184 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                     torqueFromOffset.Y = 0;
                 if (float.IsNaN(torqueFromOffset.Z))
                     torqueFromOffset.Z = 0;
-                torqueFromOffset *= m_vehicleMass;
-                Prim.ApplyTorqueImpulse(torqueFromOffset, true);
-                VDetailLog("{0},BSDynamic.MoveAngular,motorOffset,applyTorqueImpulse={1}", Prim.LocalID, torqueFromOffset);
+
+                VehicleAddAngularForce(torqueFromOffset * m_vehicleMass);
+                VDetailLog("{0},  BSDynamic.MoveAngular,motorOffset,applyTorqueImpulse={1}", Prim.LocalID, torqueFromOffset);
             }
 
-            #endregion
+        }
+        // From http://wiki.secondlife.com/wiki/Linden_Vehicle_Tutorial:
+        //      Some vehicles, like boats, should always keep their up-side up. This can be done by
+        //      enabling the "vertical attractor" behavior that springs the vehicle's local z-axis to
+        //      the world z-axis (a.k.a. "up"). To take advantage of this feature you would set the
+        //      VEHICLE_VERTICAL_ATTRACTION_TIMESCALE to control the period of the spring frequency,
+        //      and then set the VEHICLE_VERTICAL_ATTRACTION_EFFICIENCY to control the damping. An
+        //      efficiency of 0.0 will cause the spring to wobble around its equilibrium, while an
+        //      efficiency of 1.0 will cause the spring to reach its equilibrium with exponential decay.
+        public Vector3 ComputeAngularVerticalAttraction()
+        {
+            Vector3 ret = Vector3.Zero;
 
-            if ((m_flags & (VehicleFlag.NO_DEFLECTION_UP)) != 0)
+            // If vertical attaction timescale is reasonable
+            if (m_verticalAttractionTimescale < m_verticalAttractionCutoff)
             {
-                m_lastAngularVelocity.X = 0;
-                m_lastAngularVelocity.Y = 0;
-                VDetailLog("{0},MoveAngular,noDeflectionUp,lastAngular={1}", Prim.LocalID, m_lastAngularVelocity);
+                // Take a vector pointing up and convert it from world to vehicle relative coords.
+                Vector3 verticalError = Vector3.UnitZ * VehicleOrientation;
+
+                // If vertical attraction correction is needed, the vector that was pointing up (UnitZ)
+                //    is now:
+                //    leaning to one side: rotated around the X axis with the Y value going
+                //        from zero (nearly straight up) to one (completely to the side)) or
+                //    leaning front-to-back: rotated around the Y axis with the value of X being between
+                //         zero and one.
+                // The value of Z is how far the rotation is off with 1 meaning none and 0 being 90 degrees.
+
+                // Y error means needed rotation around X axis and visa versa.
+                // Since the error goes from zero to one, the asin is the corresponding angle.
+                ret.X = (float)Math.Asin(verticalError.Y);
+                // (Tilt forward (positive X) needs to tilt back (rotate negative) around Y axis.)
+                ret.Y = -(float)Math.Asin(verticalError.X);
+
+                // If verticalError.Z is negative, the vehicle is upside down. Add additional push.
+                if (verticalError.Z < 0f)
+                {
+                    ret.X += PIOverFour;
+                    ret.Y += PIOverFour;
+                }
+
+                // 'ret' is now the necessary velocity to correct tilt in one second.
+                //     Correction happens over a number of seconds.
+                Vector3 unscaledContrib = ret;
+                ret /= m_verticalAttractionTimescale;
+
+                VDetailLog("{0},  MoveAngular,verticalAttraction,,verticalError={1},unscaled={2},eff={3},ts={4},vertAttr={5}",
+                                Prim.LocalID, verticalError, unscaledContrib, m_verticalAttractionEfficiency, m_verticalAttractionTimescale, ret);
             }
+            return ret;
+        }
+
+        // Return the angular correction to correct the direction the vehicle is pointing to be
+        //      the direction is should want to be pointing.
+        // The vehicle is moving in some direction and correct its orientation to it is pointing
+        //     in that direction.
+        // TODO: implement reference frame.
+        public Vector3 ComputeAngularDeflection()
+        {
+            Vector3 ret = Vector3.Zero;
+            return ret;         // DEBUG DEBUG DEBUG
+            // Disable angular deflection for the moment.
+            // Since angularMotorUp and angularDeflection are computed independently, they will calculate
+            //     approximately the same X or Y correction. When added together (when contributions are combined)
+            //     this creates an over-correction and then wabbling as the target is overshot.
+            // TODO: rethink how the different correction computations inter-relate.
 
-            if (m_lastAngularVelocity.ApproxEquals(Vector3.Zero, 0.01f))
+            if (m_angularDeflectionEfficiency != 0)
             {
-                m_lastAngularVelocity = Vector3.Zero; // Reduce small value to zero.
-                Prim.ZeroAngularMotion(true);
-                VDetailLog("{0},MoveAngular,zeroAngularMotion,lastAngular={1}", Prim.LocalID, m_lastAngularVelocity);
+                // The direction the vehicle is moving
+                Vector3 movingDirection = VehicleVelocity;
+                movingDirection.Normalize();
+
+                // The direction the vehicle is pointing
+                Vector3 pointingDirection = Vector3.UnitX * VehicleOrientation;
+                pointingDirection.Normalize();
+
+                // The difference between what is and what should be.
+                Vector3 deflectionError = movingDirection - pointingDirection;
+
+                // Don't try to correct very large errors (not our job)
+                if (Math.Abs(deflectionError.X) > PIOverFour) deflectionError.X = 0f;
+                if (Math.Abs(deflectionError.Y) > PIOverFour) deflectionError.Y = 0f;
+                if (Math.Abs(deflectionError.Z) > PIOverFour) deflectionError.Z = 0f;
+
+                // ret = m_angularDeflectionCorrectionMotor(1f, deflectionError);
+
+                // Scale the correction by recovery timescale and efficiency
+                ret = (-deflectionError) * m_angularDeflectionEfficiency;
+                ret /= m_angularDeflectionTimescale;
+
+                VDetailLog("{0},  MoveAngular,Deflection,movingDir={1},pointingDir={2},deflectError={3},ret={4}",
+                    Prim.LocalID, movingDirection, pointingDirection, deflectionError, ret);
+                VDetailLog("{0},  MoveAngular,Deflection,fwdSpd={1},defEff={2},defTS={3}",
+                    Prim.LocalID, VehicleForwardSpeed, m_angularDeflectionEfficiency, m_angularDeflectionTimescale);
             }
-            else
+            return ret;
+        }
+
+        // Return an angular change to rotate the vehicle around the Z axis when the vehicle
+        //     is tipped around the X axis.
+        // From http://wiki.secondlife.com/wiki/Linden_Vehicle_Tutorial:
+        //      The vertical attractor feature must be enabled in order for the banking behavior to
+        //      function. The way banking works is this: a rotation around the vehicle's roll-axis will
+        //      produce a angular velocity around the yaw-axis, causing the vehicle to turn. The magnitude
+        //      of the yaw effect will be proportional to the
+        //          VEHICLE_BANKING_EFFICIENCY, the angle of the roll rotation, and sometimes the vehicle's
+        //                 velocity along its preferred axis of motion. 
+        //          The VEHICLE_BANKING_EFFICIENCY can vary between -1 and +1. When it is positive then any
+        //                  positive rotation (by the right-hand rule) about the roll-axis will effect a
+        //                  (negative) torque around the yaw-axis, making it turn to the right--that is the
+        //                  vehicle will lean into the turn, which is how real airplanes and motorcycle's work.
+        //                  Negating the banking coefficient will make it so that the vehicle leans to the
+        //                  outside of the turn (not very "physical" but might allow interesting vehicles so why not?). 
+        //           The VEHICLE_BANKING_MIX is a fake (i.e. non-physical) parameter that is useful for making
+        //                  banking vehicles do what you want rather than what the laws of physics allow.
+        //                  For example, consider a real motorcycle...it must be moving forward in order for
+        //                  it to turn while banking, however video-game motorcycles are often configured
+        //                  to turn in place when at a dead stop--because they are often easier to control
+        //                  that way using the limited interface of the keyboard or game controller. The
+        //                  VEHICLE_BANKING_MIX enables combinations of both realistic and non-realistic
+        //                  banking by functioning as a slider between a banking that is correspondingly
+        //                  totally static (0.0) and totally dynamic (1.0). By "static" we mean that the
+        //                  banking effect depends only on the vehicle's rotation about its roll-axis compared
+        //                  to "dynamic" where the banking is also proportional to its velocity along its
+        //                  roll-axis. Finding the best value of the "mixture" will probably require trial and error. 
+        //      The time it takes for the banking behavior to defeat a preexisting angular velocity about the
+        //      world z-axis is determined by the VEHICLE_BANKING_TIMESCALE. So if you want the vehicle to
+        //      bank quickly then give it a banking timescale of about a second or less, otherwise you can
+        //      make a sluggish vehicle by giving it a timescale of several seconds. 
+        public Vector3 ComputeAngularBanking()
+        {
+            Vector3 ret = Vector3.Zero;
+
+            if (m_bankingEfficiency != 0 && m_verticalAttractionTimescale < m_verticalAttractionCutoff)
             {
-                // Apply to the body.
-                // The above calculates the absolute angular velocity needed. Angular velocity is massless.
-                // Since we are stuffing the angular velocity directly into the object, the computed
-                //     velocity needs to be scaled by the timestep.
-                Vector3 applyAngularForce = ((m_lastAngularVelocity * pTimestep) - Prim.ForceRotationalVelocity);
-                Prim.ForceRotationalVelocity = applyAngularForce;
-
-                // Decay the angular movement for next time
-                Vector3 decayamount = (Vector3.One / m_angularFrictionTimescale) * pTimestep;
-                m_lastAngularVelocity *= Vector3.One - decayamount;
-
-                VDetailLog("{0},MoveAngular,done,newRotVel={1},decay={2},lastAngular={3}", 
-                                    Prim.LocalID, applyAngularForce, decayamount, m_lastAngularVelocity);
+                // This works by rotating a unit vector to the orientation of the vehicle. The
+                //    roll (tilt) will be Y component of a tilting Z vector (zero for no tilt
+                //    up to one for full over).
+                Vector3 rollComponents = Vector3.UnitZ * VehicleOrientation;
+
+                // Figure out the yaw value for this much roll.
+                float turnComponent = rollComponents.Y * rollComponents.Y * m_bankingEfficiency;
+                // Keep the sign
+                if (rollComponents.Y < 0f)
+                    turnComponent = -turnComponent;
+
+                // TODO: there must be a better computation of the banking force.
+                float bankingTurnForce = turnComponent;
+
+                //        actual error  =       static turn error            +           dynamic turn error
+                float mixedBankingError = bankingTurnForce * (1f - m_bankingMix) + bankingTurnForce * m_bankingMix * VehicleForwardSpeed;
+                // TODO: the banking effect should not go to infinity but what to limit it to?
+                mixedBankingError = ClampInRange(-20f, mixedBankingError, 20f);
+
+                // Build the force vector to change rotation from what it is to what it should be
+                ret.Z = -mixedBankingError;
+
+                // Don't do it all at once.
+                ret /= m_bankingTimescale;
+
+                VDetailLog("{0},  MoveAngular,Banking,rollComp={1},speed={2},turnComp={3},bankErr={4},mixedBankErr={5},ret={6}",
+                            Prim.LocalID, rollComponents, VehicleForwardSpeed, turnComponent, bankingTurnForce, mixedBankingError, ret);
             }
-        } //end MoveAngular
+            return ret;
+        }
 
+        // This is from previous instantiations of XXXDynamics.cs.
+        // Applies roll reference frame.
+        // TODO: is this the right way to separate the code to do this operation?
+        //    Should this be in MoveAngular()?
         internal void LimitRotation(float timestep)
         {
-            Quaternion rotq = Prim.ForceOrientation;
+            Quaternion rotq = VehicleOrientation;
             Quaternion m_rot = rotq;
             if (m_RollreferenceFrame != Quaternion.Identity)
             {
@@ -1063,12 +1333,18 @@ namespace OpenSim.Region.Physics.BulletSPlugin
             }
             if (rotq != m_rot)
             {
-                Prim.ForceOrientation = m_rot;
-                VDetailLog("{0},LimitRotation,done,orig={1},new={2}", Prim.LocalID, rotq, m_rot);
+                VehicleOrientation = m_rot;
+                VDetailLog("{0},  LimitRotation,done,orig={1},new={2}", Prim.LocalID, rotq, m_rot);
             }
 
         }
 
+        private float ClampInRange(float low, float val, float high)
+        {
+            return Math.Max(low, Math.Min(val, high));
+            // return Utils.Clamp(val, low, high);
+        }
+
         // Invoke the detailed logger and output something if it's enabled.
         private void VDetailLog(string msg, params Object[] args)
         {
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSLinkset.cs b/OpenSim/Region/Physics/BulletSPlugin/BSLinkset.cs
index 0df4310..2017fa5 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSLinkset.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSLinkset.cs
@@ -32,6 +32,15 @@ using OMV = OpenMetaverse;
 
 namespace OpenSim.Region.Physics.BulletSPlugin
 {
+
+// A BSPrim can get individual information about its linkedness attached
+//    to it through an instance of a subclass of LinksetInfo.
+// Each type of linkset will define the information needed for its type.
+public abstract class BSLinksetInfo
+{
+    public virtual void Clear() { }
+}
+
 public abstract class BSLinkset
 {
     // private static string LogHeader = "[BULLETSIM LINKSET]";
@@ -87,13 +96,6 @@ public abstract class BSLinkset
         return BSPhysicsShapeType.SHAPE_UNKNOWN;
     }
 
-    // Linksets move around the children so the linkset might need to compute the child position
-    public virtual OMV.Vector3 Position(BSPhysObject member)
-        { return member.RawPosition; }
-    public virtual OMV.Quaternion Orientation(BSPhysObject member)
-        { return member.RawOrientation; }
-    // TODO: does this need to be done for Velocity and RotationalVelocityy?
-    
     // We keep the prim's mass in the linkset structure since it could be dependent on other prims
     protected float m_mass;
     public float LinksetMass
@@ -116,7 +118,7 @@ public abstract class BSLinkset
         get { return ComputeLinksetGeometricCenter(); }
     }
 
-    protected void Initialize(BSScene scene, BSPhysObject parent)
+    protected BSLinkset(BSScene scene, BSPhysObject parent)
     {
         // A simple linkset of one (no children)
         LinksetID = m_nextLinksetID++;
@@ -127,6 +129,7 @@ public abstract class BSLinkset
         LinksetRoot = parent;
         m_children = new HashSet<BSPhysObject>();
         m_mass = parent.RawMass;
+        Rebuilding = false;
     }
 
     // Link to a linkset where the child knows the parent.
@@ -219,7 +222,7 @@ public abstract class BSLinkset
     // I am the root of a linkset and a new child is being added
     // Called while LinkActivity is locked.
     protected abstract void AddChildToLinkset(BSPhysObject child);
-
+    
     // I am the root of a linkset and one of my children is being removed.
     // Safe to call even if the child is not really in my linkset.
     protected abstract void RemoveChildFromLinkset(BSPhysObject child);
@@ -229,6 +232,10 @@ public abstract class BSLinkset
     // May be called at runtime or taint-time.
     public abstract void Refresh(BSPhysObject requestor);
 
+    // Flag denoting the linkset is in the process of being rebuilt.
+    // Used to know not the schedule a rebuild in the middle of a rebuild.
+    protected bool Rebuilding { get; set; }
+
     // The object is going dynamic (physical). Do any setup necessary
     //     for a dynamic linkset.
     // Only the state of the passed object can be modified. The rest of the linkset
@@ -245,8 +252,9 @@ public abstract class BSLinkset
 
     // Called when a parameter update comes from the physics engine for any object
     //      of the linkset is received.
+    // Passed flag is update came from physics engine (true) or the user (false).
     // Called at taint-time!!
-    public abstract void UpdateProperties(BSPhysObject physObject);
+    public abstract void UpdateProperties(BSPhysObject physObject, bool physicalUpdate);
 
     // Routine used when rebuilding the body of the root of the linkset
     // Destroy all the constraints have have been made to root.
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs b/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs
index b9c2cf9..2a7b72c 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs
@@ -28,22 +28,54 @@ using System;
 using System.Collections.Generic;
 using System.Text;
 
+using OpenSim.Framework;
+
 using OMV = OpenMetaverse;
 
 namespace OpenSim.Region.Physics.BulletSPlugin
 {
+
+// When a child is linked, the relationship position of the child to the parent
+//    is remembered so the child's world position can be recomputed when it is
+//    removed from the linkset.
+sealed class BSLinksetCompoundInfo : BSLinksetInfo
+{
+    public OMV.Vector3 OffsetPos;
+    public OMV.Quaternion OffsetRot;
+    public BSLinksetCompoundInfo(OMV.Vector3 p, OMV.Quaternion r)
+    {
+        OffsetPos = p;
+        OffsetRot = r;
+    }
+    public override void Clear()
+    {
+        OffsetPos = OMV.Vector3.Zero;
+        OffsetRot = OMV.Quaternion.Identity;
+    }
+    public override string ToString()
+    {
+        StringBuilder buff = new StringBuilder();
+        buff.Append("<p=");
+        buff.Append(OffsetPos.ToString());
+        buff.Append(",r=");
+        buff.Append(OffsetRot.ToString());
+        buff.Append(">");
+        return buff.ToString();
+    }
+};
+
 public sealed class BSLinksetCompound : BSLinkset
 {
     private static string LogHeader = "[BULLETSIM LINKSET COMPOUND]";
 
-    public BSLinksetCompound(BSScene scene, BSPhysObject parent)
+    public BSLinksetCompound(BSScene scene, BSPhysObject parent) : base(scene, parent)
     {
-        base.Initialize(scene, parent);
     }
 
     // For compound implimented linksets, if there are children, use compound shape for the root.
     public override BSPhysicsShapeType PreferredPhysicalShape(BSPhysObject requestor)
     { 
+        // Returning 'unknown' means we don't have a preference.
         BSPhysicsShapeType ret = BSPhysicsShapeType.SHAPE_UNKNOWN;
         if (IsRoot(requestor) && HasAnyChildren)
         {
@@ -55,23 +87,27 @@ public sealed class BSLinksetCompound : BSLinkset
 
     // When physical properties are changed the linkset needs to recalculate
     //   its internal properties.
-    // This is queued in the 'post taint' queue so the
-    //   refresh will happen once after all the other taints are applied.
     public override void Refresh(BSPhysObject requestor)
     {
-        // External request for Refresh (from BSPrim) is not necessary
-        // InternalRefresh(requestor);
+        // Something changed so do the rebuilding thing
+        // ScheduleRebuild();
     }
 
-    private void InternalRefresh(BSPhysObject requestor)
+    // Schedule a refresh to happen after all the other taint processing.
+    private void ScheduleRebuild(BSPhysObject requestor)
     {
-        DetailLog("{0},BSLinksetCompound.Refresh,schedulingRefresh,requestor={1}", LinksetRoot.LocalID, requestor.LocalID);
-        // Queue to happen after all the other taint processing
-        PhysicsScene.PostTaintObject("BSLinksetCompound.Refresh", requestor.LocalID, delegate()
+        DetailLog("{0},BSLinksetCompound.Refresh,schedulingRefresh,rebuilding={1}", 
+                            requestor.LocalID, Rebuilding);
+        // When rebuilding, it is possible to set properties that would normally require a rebuild.
+        //    If already rebuilding, don't request another rebuild.
+        if (!Rebuilding)
         {
-            if (IsRoot(requestor) && HasAnyChildren)
-                RecomputeLinksetCompound();
-        });
+            PhysicsScene.PostTaintObject("BSLinksetCompound.Refresh", LinksetRoot.LocalID, delegate()
+            {
+                if (HasAnyChildren)
+                    RecomputeLinksetCompound();
+            });
+        }
     }
 
     // The object is going dynamic (physical). Do any setup necessary
@@ -84,12 +120,23 @@ public sealed class BSLinksetCompound : BSLinkset
     {
         bool ret = false;
         DetailLog("{0},BSLinksetCompound.MakeDynamic,call,IsRoot={1}", child.LocalID, IsRoot(child));
-        if (!IsRoot(child))
+        if (IsRoot(child))
+        {
+            // The root is going dynamic. Make sure mass is properly set.
+            m_mass = ComputeLinksetMass();
+            ScheduleRebuild(LinksetRoot);
+        }
+        else
         {
-            // Physical children are removed from the world as the shape ofthe root compound
+            // The origional prims are removed from the world as the shape of the root compound
             //     shape takes over.
             BulletSimAPI.AddToCollisionFlags2(child.PhysBody.ptr, CollisionFlags.CF_NO_CONTACT_RESPONSE);
             BulletSimAPI.ForceActivationState2(child.PhysBody.ptr, ActivationState.DISABLE_SIMULATION);
+            // We don't want collisions from the old linkset children.
+            BulletSimAPI.RemoveFromCollisionFlags2(child.PhysBody.ptr, CollisionFlags.BS_SUBSCRIBE_COLLISION_EVENTS);
+
+            child.PhysBody.collisionType = CollisionType.LinksetChild;
+
             ret = true;
         }
         return ret;
@@ -104,33 +151,39 @@ public sealed class BSLinksetCompound : BSLinkset
     {
         bool ret = false;
         DetailLog("{0},BSLinksetCompound.MakeStatic,call,IsRoot={1}", child.LocalID, IsRoot(child));
-        if (!IsRoot(child))
+        if (IsRoot(child))
+        {
+            ScheduleRebuild(LinksetRoot);
+        }
+        else
         {
             // The non-physical children can come back to life.
             BulletSimAPI.RemoveFromCollisionFlags2(child.PhysBody.ptr, CollisionFlags.CF_NO_CONTACT_RESPONSE);
-            // Don't force activation so setting of DISABLE_SIMULATION can stay.
+
+            child.PhysBody.collisionType = CollisionType.LinksetChild;
+
+            // Don't force activation so setting of DISABLE_SIMULATION can stay if used.
             BulletSimAPI.Activate2(child.PhysBody.ptr, false);
             ret = true;
         }
         return ret;
     }
 
-    // Called at taint-time!!
-    public override void UpdateProperties(BSPhysObject updated)
+    public override void UpdateProperties(BSPhysObject updated, bool physicalUpdate)
     {
-        // Nothing to do for constraints on property updates
-    }
-
-    // The children move around in relationship to the root.
-    // Just grab the current values of wherever it is right now.
-    public override OMV.Vector3 Position(BSPhysObject member)
-    {
-        return BulletSimAPI.GetPosition2(member.PhysBody.ptr);
-    }
-
-    public override OMV.Quaternion Orientation(BSPhysObject member)
-    {
-        return BulletSimAPI.GetOrientation2(member.PhysBody.ptr);
+        // The user moving a child around requires the rebuilding of the linkset compound shape
+        // One problem is this happens when a border is crossed -- the simulator implementation
+        //    is to store the position into the group which causes the move of the object
+        //    but it also means all the child positions get updated.
+        //    What would cause an unnecessary rebuild so we make sure the linkset is in a
+        //    region before bothering to do a rebuild.
+        if (!IsRoot(updated) 
+                && !physicalUpdate 
+                && PhysicsScene.TerrainManager.IsWithinKnownTerrain(LinksetRoot.RawPosition))
+        {
+            updated.LinksetInfo = null;
+            ScheduleRebuild(updated);
+        }
     }
 
     // Routine called when rebuilding the body of some member of the linkset.
@@ -146,20 +199,58 @@ public sealed class BSLinksetCompound : BSLinkset
 
         if (!IsRoot(child))
         {
-            // Cause the current shape to be freed and the new one to be built.
-            InternalRefresh(LinksetRoot);
-            ret = true;
+            // Because it is a convenient time, recompute child world position and rotation based on
+            //    its position in the linkset.
+            RecomputeChildWorldPosition(child, true);
         }
 
+        // Cannot schedule a refresh/rebuild here because this routine is called when
+        //     the linkset is being rebuilt.
+        // InternalRefresh(LinksetRoot);
+
         return ret;
     }
 
     // Companion to RemoveBodyDependencies(). If RemoveBodyDependencies() returns 'true',
-    // this routine will restore the removed constraints.
+    //     this routine will restore the removed constraints.
     // Called at taint-time!!
     public override void RestoreBodyDependencies(BSPrim child)
     {
-        // The Refresh operation queued by RemoveBodyDependencies() will build any missing constraints.
+    }
+
+    // When the linkset is built, the child shape is added to the compound shape relative to the
+    //    root shape. The linkset then moves around but this does not move the actual child
+    //    prim. The child prim's location must be recomputed based on the location of the root shape.
+    private void RecomputeChildWorldPosition(BSPhysObject child, bool inTaintTime)
+    {
+        BSLinksetCompoundInfo lci = child.LinksetInfo as BSLinksetCompoundInfo;
+        if (lci != null)
+        {
+            if (inTaintTime)
+            {
+                OMV.Vector3 oldPos = child.RawPosition;
+                child.ForcePosition = LinksetRoot.RawPosition + lci.OffsetPos;
+                child.ForceOrientation = LinksetRoot.RawOrientation * lci.OffsetRot;
+                DetailLog("{0},BSLinksetCompound.RecomputeChildWorldPosition,oldPos={1},lci={2},newPos={3}",
+                                            child.LocalID, oldPos, lci, child.RawPosition);
+            }
+            else
+            {
+                // TaintedObject is not used here so the raw position is set now and not at taint-time.
+                child.Position = LinksetRoot.RawPosition + lci.OffsetPos;
+                child.Orientation = LinksetRoot.RawOrientation * lci.OffsetRot;
+            }
+        }
+        else
+        {
+            // This happens when children have been added to the linkset but the linkset
+            //     has not been constructed yet. So like, at taint time, adding children to a linkset
+            //     and then changing properties of the children (makePhysical, for instance)
+            //     but the post-print action of actually rebuilding the linkset has not yet happened.
+            // PhysicsScene.Logger.WarnFormat("{0} Restoring linkset child position failed because of no relative position computed. ID={1}",
+            //                                 LogHeader, child.LocalID);
+            DetailLog("{0},BSLinksetCompound.recomputeChildWorldPosition,noRelativePositonInfo", child.LocalID);
+        }
     }
 
     // ================================================================
@@ -174,14 +265,14 @@ public sealed class BSLinksetCompound : BSLinkset
 
             DetailLog("{0},BSLinksetCompound.AddChildToLinkset,call,child={1}", LinksetRoot.LocalID, child.LocalID);
 
-            // Cause constraints and assorted properties to be recomputed before the next simulation step.
-            InternalRefresh(LinksetRoot);
+            // Rebuild the compound shape with the new child shape included
+            ScheduleRebuild(child);
         }
         return;
     }
 
     // Remove the specified child from the linkset.
-    // Safe to call even if the child is not really in my linkset.
+    // Safe to call even if the child is not really in the linkset.
     protected override void RemoveChildFromLinkset(BSPhysObject child)
     {
         if (m_children.Remove(child))
@@ -192,6 +283,7 @@ public sealed class BSLinksetCompound : BSLinkset
                             child.LocalID, child.PhysBody.ptr.ToString("X"));
 
             // Cause the child's body to be rebuilt and thus restored to normal operation
+            RecomputeChildWorldPosition(child, false);
             child.ForceBodyShapeRebuild(false);
 
             if (!HasAnyChildren)
@@ -201,8 +293,8 @@ public sealed class BSLinksetCompound : BSLinkset
             }
             else
             {
-                // Schedule a rebuild of the linkset  before the next simulation tick.
-                InternalRefresh(LinksetRoot);
+                // Rebuild the compound shape with the child removed
+                ScheduleRebuild(child);
             }
         }
         return;
@@ -215,54 +307,83 @@ public sealed class BSLinksetCompound : BSLinkset
     // Called at taint time!!
     private void RecomputeLinksetCompound()
     {
-        // Cause the root shape to be rebuilt as a compound object with just the root in it
-        LinksetRoot.ForceBodyShapeRebuild(true);
+        try
+        {
+            // Suppress rebuilding while rebuilding
+            Rebuilding = true;
 
-        DetailLog("{0},BSLinksetCompound.RecomputeLinksetCompound,start,rBody={1},rShape={2},numChildren={3}",
-                        LinksetRoot.LocalID, LinksetRoot.PhysBody, LinksetRoot.PhysShape, NumberOfChildren);
+            // Cause the root shape to be rebuilt as a compound object with just the root in it
+            LinksetRoot.ForceBodyShapeRebuild(true);
 
-        // Add a shape for each of the other children in the linkset
-        ForEachMember(delegate(BSPhysObject cPrim)
-        {
-            if (!IsRoot(cPrim))
+            DetailLog("{0},BSLinksetCompound.RecomputeLinksetCompound,start,rBody={1},rShape={2},numChildren={3}",
+                            LinksetRoot.LocalID, LinksetRoot.PhysBody, LinksetRoot.PhysShape, NumberOfChildren);
+
+            // Add a shape for each of the other children in the linkset
+            ForEachMember(delegate(BSPhysObject cPrim)
             {
-                // Each child position and rotation is given relative to the root.
-                OMV.Quaternion invRootOrientation = OMV.Quaternion.Inverse(LinksetRoot.RawOrientation);
-                OMV.Vector3 displacementPos = (cPrim.RawPosition - LinksetRoot.RawPosition) * invRootOrientation;
-                OMV.Quaternion displacementRot = cPrim.RawOrientation * invRootOrientation;
+                if (!IsRoot(cPrim))
+                {
+                    // Compute the displacement of the child from the root of the linkset.
+                    // This info is saved in the child prim so the relationship does not
+                    //    change over time and the new child position can be computed
+                    //    when the linkset is being disassembled (the linkset may have moved).
+                    BSLinksetCompoundInfo lci = cPrim.LinksetInfo as BSLinksetCompoundInfo;
+                    if (lci == null)
+                    {
+                        // Each child position and rotation is given relative to the root.
+                        OMV.Quaternion invRootOrientation = OMV.Quaternion.Inverse(LinksetRoot.RawOrientation);
+                        OMV.Vector3 displacementPos = (cPrim.RawPosition - LinksetRoot.RawPosition) * invRootOrientation;
+                        OMV.Quaternion displacementRot = cPrim.RawOrientation * invRootOrientation;
+
+                        // Save relative position for recomputing child's world position after moving linkset.
+                        lci = new BSLinksetCompoundInfo(displacementPos, displacementRot);
+                        cPrim.LinksetInfo = lci;
+                        DetailLog("{0},BSLinksetCompound.RecomputeLinksetCompound,creatingRelPos,lci={1}", cPrim.LocalID, lci);
+                    }
 
-                DetailLog("{0},BSLinksetCompound.RecomputeLinksetCompound,addMemberToShape,mID={1},mShape={2},dispPos={3},dispRot={4}",
-                    LinksetRoot.LocalID, cPrim.LocalID, cPrim.PhysShape, displacementPos, displacementRot);
+                    DetailLog("{0},BSLinksetCompound.RecomputeLinksetCompound,addMemberToShape,mID={1},mShape={2},dispPos={3},dispRot={4}",
+                        LinksetRoot.LocalID, cPrim.LocalID, cPrim.PhysShape, lci.OffsetPos, lci.OffsetRot);
 
-                if (cPrim.PhysShape.isNativeShape)
-                {
-                    // Native shapes are not shared so we need to create a new one.
-                    // A mesh or hull is created because scale is not available on a native shape.
-                    //     (TODO: Bullet does have a btScaledCollisionShape. Can that be used?)
-                    BulletShape saveShape = cPrim.PhysShape;
-                    cPrim.PhysShape.ptr = IntPtr.Zero;  // Don't let the create free the child's shape
-                    PhysicsScene.Shapes.CreateGeomMeshOrHull(cPrim, null);
-                    BulletShape newShape = cPrim.PhysShape;
-                    cPrim.PhysShape = saveShape;
-                    BulletSimAPI.AddChildShapeToCompoundShape2(LinksetRoot.PhysShape.ptr, newShape.ptr, displacementPos, displacementRot);
-                }
-                else
-                {
-                    // For the shared shapes (meshes and hulls), just use the shape in the child.
-                    if (PhysicsScene.Shapes.ReferenceShape(cPrim.PhysShape))
+                    if (cPrim.PhysShape.isNativeShape)
+                    {
+                        // A native shape is turning into a hull collision shape because native
+                        //    shapes are not shared so we have to hullify it so it will be tracked
+                        //    and freed at the correct time. This also solves the scaling problem
+                        //    (native shapes scaled but hull/meshes are assumed to not be).
+                        // TODO: decide of the native shape can just be used in the compound shape.
+                        //    Use call to CreateGeomNonSpecial().
+                        BulletShape saveShape = cPrim.PhysShape;
+                        cPrim.PhysShape.Clear();        // Don't let the create free the child's shape
+                        // PhysicsScene.Shapes.CreateGeomNonSpecial(true, cPrim, null);
+                        PhysicsScene.Shapes.CreateGeomMeshOrHull(cPrim, null);
+                        BulletShape newShape = cPrim.PhysShape;
+                        cPrim.PhysShape = saveShape;
+                        BulletSimAPI.AddChildShapeToCompoundShape2(LinksetRoot.PhysShape.ptr, newShape.ptr, lci.OffsetPos, lci.OffsetRot);
+                    }
+                    else
                     {
-                        PhysicsScene.Logger.ErrorFormat("{0} Rebuilt sharable shape when building linkset! Region={1}, primID={2}, shape={3}",
-                                            LogHeader, PhysicsScene.RegionName, cPrim.LocalID, cPrim.PhysShape);
+                        // For the shared shapes (meshes and hulls), just use the shape in the child.
+                        // The reference count added here will be decremented when the compound shape
+                        //     is destroyed in BSShapeCollection (the child shapes are looped over and dereferenced).
+                        if (PhysicsScene.Shapes.ReferenceShape(cPrim.PhysShape))
+                        {
+                            PhysicsScene.Logger.ErrorFormat("{0} Rebuilt sharable shape when building linkset! Region={1}, primID={2}, shape={3}",
+                                                LogHeader, PhysicsScene.RegionName, cPrim.LocalID, cPrim.PhysShape);
+                        }
+                        BulletSimAPI.AddChildShapeToCompoundShape2(LinksetRoot.PhysShape.ptr, cPrim.PhysShape.ptr, lci.OffsetPos, lci.OffsetRot);
                     }
-                    BulletSimAPI.AddChildShapeToCompoundShape2(LinksetRoot.PhysShape.ptr, cPrim.PhysShape.ptr, displacementPos, displacementRot);
                 }
-            }
-            return false;   // 'false' says to move onto the next child in the list
-        });
+                return false;   // 'false' says to move onto the next child in the list
+            });
 
-        // With all of the linkset packed into the root prim, it has the mass of everyone.
-        float linksetMass = LinksetMass;
-        LinksetRoot.UpdatePhysicalMassProperties(linksetMass);
+            // With all of the linkset packed into the root prim, it has the mass of everyone.
+            float linksetMass = LinksetMass;
+            LinksetRoot.UpdatePhysicalMassProperties(linksetMass);
+        }
+        finally
+        {
+            Rebuilding = false;
+        }
 
         BulletSimAPI.RecalculateCompoundShapeLocalAabb2(LinksetRoot.PhysShape.ptr);
 
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSLinksetConstraints.cs b/OpenSim/Region/Physics/BulletSPlugin/BSLinksetConstraints.cs
index c855fda..8c36c31 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSLinksetConstraints.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSLinksetConstraints.cs
@@ -36,9 +36,8 @@ public sealed class BSLinksetConstraints : BSLinkset
 {
     // private static string LogHeader = "[BULLETSIM LINKSET CONSTRAINTS]";
 
-    public BSLinksetConstraints(BSScene scene, BSPhysObject parent)
+    public BSLinksetConstraints(BSScene scene, BSPhysObject parent) : base(scene, parent)
     {
-        base.Initialize(scene, parent);
     }
 
     // When physical properties are changed the linkset needs to recalculate
@@ -79,23 +78,11 @@ public sealed class BSLinksetConstraints : BSLinkset
     }
 
     // Called at taint-time!!
-    public override void UpdateProperties(BSPhysObject updated)
+    public override void UpdateProperties(BSPhysObject updated, bool inTaintTime)
     {
         // Nothing to do for constraints on property updates
     }
 
-    // The children of the linkset are moved around by the constraints.
-    // Just grab the current values of wherever it is right now.
-    public override OMV.Vector3 Position(BSPhysObject member)
-    {
-        return BulletSimAPI.GetPosition2(member.PhysBody.ptr);
-    }
-
-    public override OMV.Quaternion Orientation(BSPhysObject member)
-    {
-        return BulletSimAPI.GetOrientation2(member.PhysBody.ptr);
-    }
-
     // Routine called when rebuilding the body of some member of the linkset.
     // Destroy all the constraints have have been made to root and set
     //     up to rebuild the constraints before the next simulation step.
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSMaterials.cs b/OpenSim/Region/Physics/BulletSPlugin/BSMaterials.cs
new file mode 100755
index 0000000..c113a43
--- /dev/null
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSMaterials.cs
@@ -0,0 +1,200 @@
+/*
+ * Copyright (c) Contributors, http://opensimulator.org/
+ * See CONTRIBUTORS.TXT for a full list of copyright holders.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyrightD
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of the OpenSimulator Project nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Reflection;
+using Nini.Config;
+
+namespace OpenSim.Region.Physics.BulletSPlugin
+{
+
+public struct MaterialAttributes
+{
+    // Material type values that correspond with definitions for LSL
+    public enum Material : int
+    {
+        Stone = 0,
+        Metal,
+        Glass,
+        Wood,
+        Flesh,
+        Plastic,
+        Rubber,
+        Light,
+        // Hereafter are BulletSim additions
+        Avatar,
+        NumberOfTypes   // the count of types in the enum.
+    }
+
+    // Names must be in the order of the above enum.
+    // These names must coorespond to the lower case field names in the MaterialAttributes
+    //     structure as reflection is used to select the field to put the value in.
+    public static readonly string[] MaterialAttribs = { "Density", "Friction", "Restitution"};
+
+    public MaterialAttributes(string t, float d, float f, float r)
+    {
+        type = t;
+        density = d;
+        friction = f;
+        restitution = r;
+    }
+    public string type;
+    public float density;
+    public float friction;
+    public float restitution;
+}
+
+public static class BSMaterials
+{
+    // Attributes for each material type
+    private static readonly MaterialAttributes[] Attributes;
+
+    // Map of material name to material type code
+    public static readonly Dictionary<string, MaterialAttributes.Material> MaterialMap;
+
+    static BSMaterials()
+    {
+        // Attribute sets for both the non-physical and physical instances of materials.
+        Attributes = new MaterialAttributes[(int)MaterialAttributes.Material.NumberOfTypes * 2];
+
+        // Map of name to type code.
+        MaterialMap = new Dictionary<string, MaterialAttributes.Material>();
+        MaterialMap.Add("Stone", MaterialAttributes.Material.Stone);
+        MaterialMap.Add("Metal", MaterialAttributes.Material.Metal);
+        MaterialMap.Add("Glass", MaterialAttributes.Material.Glass);
+        MaterialMap.Add("Wood", MaterialAttributes.Material.Wood);
+        MaterialMap.Add("Flesh", MaterialAttributes.Material.Flesh);
+        MaterialMap.Add("Plastic", MaterialAttributes.Material.Plastic);
+        MaterialMap.Add("Rubber", MaterialAttributes.Material.Rubber);
+        MaterialMap.Add("Light", MaterialAttributes.Material.Light);
+        MaterialMap.Add("Avatar", MaterialAttributes.Material.Avatar);
+    }
+
+    // This is where all the default material attributes are defined.
+    public static void InitializeFromDefaults(ConfigurationParameters parms)
+    {
+        // Values from http://wiki.secondlife.com/wiki/PRIM_MATERIAL
+        float dDensity = parms.defaultDensity;
+        float dFriction = parms.defaultFriction;
+        float dRestitution = parms.defaultRestitution;
+        Attributes[(int)MaterialAttributes.Material.Stone] =
+                    new MaterialAttributes("stone",dDensity, 0.8f, 0.4f);
+        Attributes[(int)MaterialAttributes.Material.Metal] =
+                    new MaterialAttributes("metal",dDensity, 0.3f, 0.4f);
+        Attributes[(int)MaterialAttributes.Material.Glass] =
+                    new MaterialAttributes("glass",dDensity, 0.2f, 0.7f);
+        Attributes[(int)MaterialAttributes.Material.Wood] =
+                    new MaterialAttributes("wood",dDensity, 0.6f, 0.5f);
+        Attributes[(int)MaterialAttributes.Material.Flesh] =
+                    new MaterialAttributes("flesh",dDensity, 0.9f, 0.3f);
+        Attributes[(int)MaterialAttributes.Material.Plastic] =
+                    new MaterialAttributes("plastic",dDensity, 0.4f, 0.7f);
+        Attributes[(int)MaterialAttributes.Material.Rubber] =
+                    new MaterialAttributes("rubber",dDensity, 0.9f, 0.9f);
+        Attributes[(int)MaterialAttributes.Material.Light] =
+                    new MaterialAttributes("light",dDensity, dFriction, dRestitution);
+        Attributes[(int)MaterialAttributes.Material.Avatar] =
+                    new MaterialAttributes("avatar",60f, 0.2f, 0f);
+
+        Attributes[(int)MaterialAttributes.Material.Stone + (int)MaterialAttributes.Material.NumberOfTypes] =
+                    new MaterialAttributes("stonePhysical",dDensity, 0.8f, 0.4f);
+        Attributes[(int)MaterialAttributes.Material.Metal + (int)MaterialAttributes.Material.NumberOfTypes] =
+                    new MaterialAttributes("metalPhysical",dDensity, 0.8f, 0.4f);
+        Attributes[(int)MaterialAttributes.Material.Glass + (int)MaterialAttributes.Material.NumberOfTypes] =
+                    new MaterialAttributes("glassPhysical",dDensity, 0.8f, 0.7f);
+        Attributes[(int)MaterialAttributes.Material.Wood + (int)MaterialAttributes.Material.NumberOfTypes] =
+                    new MaterialAttributes("woodPhysical",dDensity, 0.8f, 0.5f);
+        Attributes[(int)MaterialAttributes.Material.Flesh + (int)MaterialAttributes.Material.NumberOfTypes] =
+                    new MaterialAttributes("fleshPhysical",dDensity, 0.8f, 0.3f);
+        Attributes[(int)MaterialAttributes.Material.Plastic + (int)MaterialAttributes.Material.NumberOfTypes] =
+                    new MaterialAttributes("plasticPhysical",dDensity, 0.8f, 0.7f);
+        Attributes[(int)MaterialAttributes.Material.Rubber + (int)MaterialAttributes.Material.NumberOfTypes] =
+                    new MaterialAttributes("rubberPhysical",dDensity, 0.8f, 0.9f);
+        Attributes[(int)MaterialAttributes.Material.Light + (int)MaterialAttributes.Material.NumberOfTypes] =
+                    new MaterialAttributes("lightPhysical",dDensity, dFriction, dRestitution);
+        Attributes[(int)MaterialAttributes.Material.Avatar + (int)MaterialAttributes.Material.NumberOfTypes] =
+                    new MaterialAttributes("avatarPhysical",60f, 0.2f, 0f);
+    }
+
+    // Under the [BulletSim] section, one can change the individual material
+    //    attribute values. The format of the configuration parameter is:
+    //        <materialName><Attribute>["Physical"] = floatValue
+    //    For instance:
+    //        [BulletSim]
+    //             StoneFriction = 0.2
+    //             FleshRestitutionPhysical = 0.8
+    // Materials can have different parameters for their static and
+    //    physical instantiations. When setting the non-physical value,
+    //    both values are changed. Setting the physical value only changes
+    //    the physical value.
+    public static void InitializefromParameters(IConfig pConfig)
+    {
+        foreach (KeyValuePair<string, MaterialAttributes.Material> kvp in MaterialMap)
+        {
+            string matName = kvp.Key;
+            foreach (string attribName in MaterialAttributes.MaterialAttribs)
+            {
+                string paramName = matName + attribName;
+                if (pConfig.Contains(paramName))
+                {
+                    float paramValue = pConfig.GetFloat(paramName);
+                    SetAttributeValue((int)kvp.Value, attribName, paramValue);
+                    // set the physical value also
+                    SetAttributeValue((int)kvp.Value + (int)MaterialAttributes.Material.NumberOfTypes, attribName, paramValue);
+                }
+                paramName += "Physical";
+                if (pConfig.Contains(paramName))
+                {
+                    float paramValue = pConfig.GetFloat(paramName);
+                    SetAttributeValue((int)kvp.Value + (int)MaterialAttributes.Material.NumberOfTypes, attribName, paramValue);
+                }
+            }
+        }
+    }
+
+    // Use reflection to set the value in the attribute structure.
+    private static void SetAttributeValue(int matType, string attribName, float val)
+    {
+        MaterialAttributes thisAttrib = Attributes[matType];
+        FieldInfo fieldInfo = thisAttrib.GetType().GetField(attribName.ToLower());
+        if (fieldInfo != null)
+        {
+            fieldInfo.SetValue(thisAttrib, val);
+            Attributes[matType] = thisAttrib;
+        }
+    }
+
+    // Given a material type, return a structure of attributes.
+    public static MaterialAttributes GetAttributes(MaterialAttributes.Material type, bool isPhysical)
+    {
+        int ind = (int)type;
+        if (isPhysical) ind += (int)MaterialAttributes.Material.NumberOfTypes;
+        return Attributes[ind];
+    }
+}
+}
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSMotors.cs b/OpenSim/Region/Physics/BulletSPlugin/BSMotors.cs
index bc6e4c4..34a87c6 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSMotors.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSMotors.cs
@@ -1,104 +1,327 @@
-using System;

-using System.Collections.Generic;

-using System.Text;

-using OpenMetaverse;

-

-namespace OpenSim.Region.Physics.BulletSPlugin

-{

-public abstract class BSMotor

-{

-    public virtual void Reset() { }

-    public virtual void Zero() { }

-}

-// Can all the incremental stepping be replaced with motor classes?

-public class BSVMotor : BSMotor

-{

-    public Vector3 FrameOfReference { get; set; }

-    public Vector3 Offset { get; set; }

-

-    public float TimeScale { get; set; }

-    public float TargetValueDecayTimeScale { get; set; }

-    public Vector3 CurrentValueReductionTimescale { get; set; }

-    public float Efficiency { get; set; }

-

-    public Vector3 TargetValue { get; private set; }

-    public Vector3 CurrentValue { get; private set; }

-

-

-

-    BSVMotor(float timeScale, float decayTimeScale, Vector3 frictionTimeScale, float efficiency)

-    {

-        TimeScale = timeScale;

-        TargetValueDecayTimeScale = decayTimeScale;

-        CurrentValueReductionTimescale = frictionTimeScale;

-        Efficiency = efficiency;

-    }

-    public void SetCurrent(Vector3 current)

-    {

-        CurrentValue = current;

-    }

-    public void SetTarget(Vector3 target)

-    {

-        TargetValue = target;

-    }

-    public Vector3 Step(float timeStep)

-    {

-        if (CurrentValue.LengthSquared() > 0.001f)

-        {

-            // Vector3 origDir = Target;       // DEBUG

-            // Vector3 origVel = CurrentValue;   // DEBUG

-

-            // Add (desiredVelocity - currentAppliedVelocity) / howLongItShouldTakeToComplete

-            Vector3 addAmount = (TargetValue - CurrentValue)/(TargetValue) * timeStep;

-            CurrentValue += addAmount;

-

-            float decayFactor = (1.0f / TargetValueDecayTimeScale) * timeStep;

-            TargetValue *= (1f - decayFactor);

-

-            Vector3 frictionFactor = (Vector3.One / CurrentValueReductionTimescale) * timeStep;

-            CurrentValue *= (Vector3.One - frictionFactor);

-        }

-        else

-        {

-            // if what remains of direction is very small, zero it.

-            TargetValue = Vector3.Zero;

-            CurrentValue = Vector3.Zero;

-

-            // VDetailLog("{0},MoveLinear,zeroed", Prim.LocalID);

-        }

-        return CurrentValue;

-    }

-}

-

-public class BSFMotor : BSMotor

-{

-    public float TimeScale { get; set; }

-    public float DecayTimeScale { get; set; }

-    public float Friction { get; set; }

-    public float Efficiency { get; set; }

-

-    public float Target { get; private set; }

-    public float CurrentValue { get; private set; }

-

-    BSFMotor(float timeScale, float decayTimescale, float friction, float efficiency)

-    {

-    }

-    public void SetCurrent(float target)

-    {

-    }

-    public void SetTarget(float target)

-    {

-    }

-    public float Step(float timeStep)

-    {

-        return 0f;

-    }

-}

-public class BSPIDMotor : BSMotor

-{

-    // TODO: write and use this one

-    BSPIDMotor()

-    {

-    }

-}

-}

+/*
+ * Copyright (c) Contributors, http://opensimulator.org/
+ * See CONTRIBUTORS.TXT for a full list of copyright holders.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of the OpenSimulator Project nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+using System;
+using System.Collections.Generic;
+using System.Text;
+using OpenMetaverse;
+using OpenSim.Framework;
+
+namespace OpenSim.Region.Physics.BulletSPlugin
+{
+public abstract class BSMotor
+{
+    // Timescales and other things can be turned off by setting them to 'infinite'.
+    public const float Infinite = 12345.6f;
+    public readonly static Vector3 InfiniteVector = new Vector3(BSMotor.Infinite, BSMotor.Infinite, BSMotor.Infinite);
+
+    public BSMotor(string useName)
+    {
+        UseName = useName;
+        PhysicsScene = null;
+    }
+    public virtual void Reset() { }
+    public virtual void Zero() { }
+    public virtual void GenerateTestOutput(float timeStep) { }
+
+    // A name passed at motor creation for easily identifyable debugging messages.
+    public string UseName { get; private set; }
+
+    // Used only for outputting debug information. Might not be set so check for null.
+    public BSScene PhysicsScene { get; set; }
+    protected void MDetailLog(string msg, params Object[] parms)
+    {
+        if (PhysicsScene != null)
+        {
+            if (PhysicsScene.VehicleLoggingEnabled)
+            {
+                PhysicsScene.DetailLog(msg, parms);
+            }
+        }
+    }
+}
+
+// Motor which moves CurrentValue to TargetValue over TimeScale seconds.
+// The TargetValue decays in TargetValueDecayTimeScale and
+//     the CurrentValue will be held back by FrictionTimeScale.
+// This motor will "zero itself" over time in that the targetValue will
+//    decay to zero and the currentValue will follow it to that zero.
+//    The overall effect is for the returned correction value to go from large
+//    values (the total difference between current and target minus friction)
+//    to small and eventually zero values.
+// TimeScale and TargetDelayTimeScale may be 'infinite' which means no decay.
+
+// For instance, if something is moving at speed X and the desired speed is Y,
+//    CurrentValue is X and TargetValue is Y. As the motor is stepped, new
+//    values of CurrentValue are returned that approach the TargetValue.
+// The feature of decaying TargetValue is so vehicles will eventually
+//    come to a stop rather than run forever. This can be disabled by
+//    setting TargetValueDecayTimescale to 'infinite'.
+// The change from CurrentValue to TargetValue is linear over TimeScale seconds.
+public class BSVMotor : BSMotor
+{
+    // public Vector3 FrameOfReference { get; set; }
+    // public Vector3 Offset { get; set; }
+
+    public virtual float TimeScale { get; set; }
+    public virtual float TargetValueDecayTimeScale { get; set; }
+    public virtual Vector3 FrictionTimescale { get; set; }
+    public virtual float Efficiency { get; set; }
+
+    public virtual float ErrorZeroThreshold { get; set; }
+
+    public virtual Vector3 TargetValue { get; protected set; }
+    public virtual Vector3 CurrentValue { get; protected set; }
+    public virtual Vector3 LastError { get; protected set; }
+
+    public BSVMotor(string useName)
+        : base(useName)
+    {
+        TimeScale = TargetValueDecayTimeScale = BSMotor.Infinite;
+        Efficiency = 1f;
+        FrictionTimescale = BSMotor.InfiniteVector;
+        CurrentValue = TargetValue = Vector3.Zero;
+        ErrorZeroThreshold = 0.01f;
+    }
+    public BSVMotor(string useName, float timeScale, float decayTimeScale, Vector3 frictionTimeScale, float efficiency) 
+        : this(useName)
+    {
+        TimeScale = timeScale;
+        TargetValueDecayTimeScale = decayTimeScale;
+        FrictionTimescale = frictionTimeScale;
+        Efficiency = efficiency;
+        CurrentValue = TargetValue = Vector3.Zero;
+    }
+    public void SetCurrent(Vector3 current)
+    {
+        CurrentValue = current;
+    }
+    public void SetTarget(Vector3 target)
+    {
+        TargetValue = target;
+    }
+    public override void Zero()
+    {
+        base.Zero();
+        CurrentValue = TargetValue = Vector3.Zero;
+    }
+
+    // Compute the next step and return the new current value
+    public virtual Vector3 Step(float timeStep)
+    {
+        Vector3 origTarget = TargetValue;       // DEBUG
+        Vector3 origCurrVal = CurrentValue;     // DEBUG
+
+        Vector3 correction = Vector3.Zero;
+        Vector3 error = TargetValue - CurrentValue;
+        if (!error.ApproxEquals(Vector3.Zero, ErrorZeroThreshold))
+        {
+            correction = Step(timeStep, error);
+
+            CurrentValue += correction;
+
+            // The desired value reduces to zero which also reduces the difference with current.
+            // If the decay time is infinite, don't decay at all.
+            float decayFactor = 0f;
+            if (TargetValueDecayTimeScale != BSMotor.Infinite)
+            {
+                decayFactor = (1.0f / TargetValueDecayTimeScale) * timeStep;
+                TargetValue *= (1f - decayFactor);
+            }
+
+            // The amount we can correct the error is reduced by the friction
+            Vector3 frictionFactor = Vector3.Zero;
+            if (FrictionTimescale != BSMotor.InfiniteVector)
+            {
+                // frictionFactor = (Vector3.One / FrictionTimescale) * timeStep;
+                // Individual friction components can be 'infinite' so compute each separately.
+                frictionFactor.X = (FrictionTimescale.X == BSMotor.Infinite) ? 0f : (1f / FrictionTimescale.X);
+                frictionFactor.Y = (FrictionTimescale.Y == BSMotor.Infinite) ? 0f : (1f / FrictionTimescale.Y);
+                frictionFactor.Z = (FrictionTimescale.Z == BSMotor.Infinite) ? 0f : (1f / FrictionTimescale.Z);
+                frictionFactor *= timeStep;
+                CurrentValue *= (Vector3.One - frictionFactor);
+            }
+
+            MDetailLog("{0},  BSVMotor.Step,nonZero,{1},origCurr={2},origTarget={3},timeStep={4},err={5},corr={6}",
+                                BSScene.DetailLogZero, UseName, origCurrVal, origTarget,
+                                timeStep, error, correction);
+            MDetailLog("{0},  BSVMotor.Step,nonZero,{1},tgtDecayTS={2},decayFact={3},frictTS={4},frictFact={5},tgt={6},curr={7}",
+                                BSScene.DetailLogZero, UseName,
+                                TargetValueDecayTimeScale, decayFactor, FrictionTimescale, frictionFactor,
+                                TargetValue, CurrentValue);
+        }
+        else
+        {
+            // Difference between what we have and target is small. Motor is done.
+            CurrentValue = TargetValue;
+            MDetailLog("{0},  BSVMotor.Step,zero,{1},origTgt={2},origCurr={3},ret={2}",
+                        BSScene.DetailLogZero, UseName, origCurrVal, origTarget, CurrentValue);
+        }
+
+        return CurrentValue;
+    }
+    public virtual Vector3 Step(float timeStep, Vector3 error)
+    {
+        LastError = error;
+        Vector3 returnCorrection = Vector3.Zero;
+        if (!error.ApproxEquals(Vector3.Zero, ErrorZeroThreshold))
+        {
+            // correction =  error / secondsItShouldTakeToCorrect
+            Vector3 correctionAmount;
+            if (TimeScale == 0f || TimeScale == BSMotor.Infinite)
+                correctionAmount = error * timeStep;
+            else
+                correctionAmount = error / TimeScale * timeStep;
+
+            returnCorrection = correctionAmount;
+            MDetailLog("{0},  BSVMotor.Step,nonZero,{1},timeStep={2},timeScale={3},err={4},corr={5}",
+                                    BSScene.DetailLogZero, UseName, timeStep, TimeScale, error, correctionAmount);
+        }
+        return returnCorrection;
+    }
+
+    // The user sets all the parameters and calls this which outputs values until error is zero.
+    public override void GenerateTestOutput(float timeStep)
+    {
+        // maximum number of outputs to generate.
+        int maxOutput = 50;
+        MDetailLog("{0},BSVMotor.Test,{1},===================================== BEGIN Test Output", BSScene.DetailLogZero, UseName);
+        MDetailLog("{0},BSVMotor.Test,{1},timeScale={2},targDlyTS={3},frictTS={4},eff={5},curr={6},tgt={7}",
+                                BSScene.DetailLogZero, UseName,
+                                TimeScale, TargetValueDecayTimeScale, FrictionTimescale, Efficiency, 
+                                CurrentValue, TargetValue);
+
+        LastError = BSMotor.InfiniteVector;
+        while (maxOutput-- > 0 && !LastError.ApproxEquals(Vector3.Zero, ErrorZeroThreshold))
+        {
+            Vector3 lastStep = Step(timeStep);
+            MDetailLog("{0},BSVMotor.Test,{1},cur={2},tgt={3},lastError={4},lastStep={5}",
+                            BSScene.DetailLogZero, UseName, CurrentValue, TargetValue, LastError, lastStep);
+        }
+        MDetailLog("{0},BSVMotor.Test,{1},===================================== END Test Output", BSScene.DetailLogZero, UseName);
+        
+
+    }
+
+    public override string ToString()
+    {
+        return String.Format("<{0},curr={1},targ={2},decayTS={3},frictTS={4}>",
+            UseName, CurrentValue, TargetValue, TargetValueDecayTimeScale, FrictionTimescale);
+    }
+}
+
+public class BSFMotor : BSMotor
+{
+    public float TimeScale { get; set; }
+    public float DecayTimeScale { get; set; }
+    public float Friction { get; set; }
+    public float Efficiency { get; set; }
+
+    public float Target { get; private set; }
+    public float CurrentValue { get; private set; }
+
+    public BSFMotor(string useName, float timeScale, float decayTimescale, float friction, float efficiency)
+        : base(useName)
+    {
+    }
+    public void SetCurrent(float target)
+    {
+    }
+    public void SetTarget(float target)
+    {
+    }
+    public virtual float Step(float timeStep)
+    {
+        return 0f;
+    }
+}
+
+// Proportional, Integral, Derivitive Motor
+// Good description at http://www.answers.com/topic/pid-controller . Includes processes for choosing p, i and d factors.
+public class BSPIDVMotor : BSVMotor
+{
+    // Larger makes more overshoot, smaller means converge quicker. Range of 0.1 to 10.
+    public Vector3 proportionFactor { get; set; }
+    public Vector3 integralFactor { get; set; }
+    public Vector3 derivFactor { get; set; }
+    // Arbritrary factor range.
+    // EfficiencyHigh means move quickly to the correct number. EfficiencyLow means might over correct.
+    public float EfficiencyHigh = 0.4f;
+    public float EfficiencyLow = 4.0f;
+
+    Vector3 IntegralFactor { get; set; }
+
+    public BSPIDVMotor(string useName)
+        : base(useName)
+    {
+        proportionFactor = new Vector3(1.00f, 1.00f, 1.00f);
+        integralFactor = new Vector3(1.00f, 1.00f, 1.00f);
+        derivFactor = new Vector3(1.00f, 1.00f, 1.00f);
+        IntegralFactor = Vector3.Zero;
+        LastError = Vector3.Zero;
+    }
+
+    public override void Zero()
+    {
+        base.Zero();
+    }
+
+    public override float Efficiency
+    {
+        get { return base.Efficiency; }
+        set
+        {
+            base.Efficiency = Util.Clamp(value, 0f, 1f);
+            // Compute factors based on efficiency.
+            // If efficiency is high (1f), use a factor value that moves the error value to zero with little overshoot.
+            // If efficiency is low (0f), use a factor value that overcorrects.
+            // TODO: might want to vary contribution of different factor depending on efficiency.
+            float factor = ((1f - this.Efficiency) * EfficiencyHigh + EfficiencyLow) / 3f;
+            // float factor = (1f - this.Efficiency) * EfficiencyHigh + EfficiencyLow;
+            proportionFactor = new Vector3(factor, factor, factor);
+            integralFactor = new Vector3(factor, factor, factor);
+            derivFactor = new Vector3(factor, factor, factor);
+        }
+    }
+
+    // Ignore Current and Target Values and just advance the PID computation on this error.
+    public override Vector3 Step(float timeStep, Vector3 error)
+    {
+        // Add up the error so we can integrate over the accumulated errors
+        IntegralFactor += error * timeStep;
+
+        // A simple derivitive is the rate of change from the last error.
+        Vector3 derivFactor = (error - LastError) * timeStep;
+        LastError = error;
+
+        // Correction = -(proportionOfPresentError +      accumulationOfPastError    +     rateOfChangeOfError)
+        Vector3 ret   = -(error * proportionFactor + IntegralFactor * integralFactor + derivFactor * derivFactor);
+
+        return ret;
+    }
+}
+}
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSPhysObject.cs b/OpenSim/Region/Physics/BulletSPlugin/BSPhysObject.cs
index f6a890e..92a5f2f 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSPhysObject.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSPhysObject.cs
@@ -60,6 +60,9 @@ public abstract class BSPhysObject : PhysicsActor
         Linkset = BSLinkset.Factory(PhysicsScene, this);
         LastAssetBuildFailed = false;
 
+        // Default material type
+        Material = MaterialAttributes.Material.Wood;
+
         CollisionCollection = new CollisionEventUpdate();
         SubscribedEventsMs = 0;
         CollidingStep = 0;
@@ -72,6 +75,7 @@ public abstract class BSPhysObject : PhysicsActor
     public string TypeName { get; protected set; }
 
     public BSLinkset Linkset { get; set; }
+    public BSLinksetInfo LinksetInfo { get; set; }
 
     // Return the object mass without calculating it or having side effects
     public abstract float RawMass { get; }
@@ -105,10 +109,17 @@ public abstract class BSPhysObject : PhysicsActor
     public EntityProperties CurrentEntityProperties { get; set; }
     public EntityProperties LastEntityProperties { get; set; }
 
-    public abstract OMV.Vector3 Scale { get; set; }
+    public virtual OMV.Vector3 Scale { get; set; }
     public abstract bool IsSolid { get; }
     public abstract bool IsStatic { get; }
 
+    // Materialness
+    public MaterialAttributes.Material Material { get; private set; }
+    public override void SetMaterial(int material)
+    {
+        Material = (MaterialAttributes.Material)material;
+    }
+
     // Stop all physical motion.
     public abstract void ZeroMotion(bool inTaintTime);
     public abstract void ZeroAngularMotion(bool inTaintTime);
@@ -128,6 +139,17 @@ public abstract class BSPhysObject : PhysicsActor
     public abstract OMV.Quaternion RawOrientation { get; set; }
     public abstract OMV.Quaternion ForceOrientation { get; set; }
 
+    // The system is telling us the velocity it wants to move at.
+    protected OMV.Vector3 m_targetVelocity;
+    public override OMV.Vector3 TargetVelocity
+    {
+        get { return m_targetVelocity; }
+        set
+        {
+            m_targetVelocity = value;
+            Velocity = value;
+        }
+    }
     public abstract OMV.Vector3 ForceVelocity { get; set; }
 
     public abstract OMV.Vector3 ForceRotationalVelocity { get; set; }
@@ -192,7 +214,7 @@ public abstract class BSPhysObject : PhysicsActor
     {
         bool ret = true;
         // If the 'no collision' call, force it to happen right now so quick collision_end
-        bool force = CollisionCollection.Count == 0;
+        bool force = (CollisionCollection.Count == 0);
 
         // throttle the collisions to the number of milliseconds specified in the subscription
         if (force || (PhysicsScene.SimulationNowTime >= NextCollisionOkTime))
@@ -210,8 +232,10 @@ public abstract class BSPhysObject : PhysicsActor
             // DetailLog("{0},{1}.SendCollisionUpdate,call,numCollisions={2}", LocalID, TypeName, CollisionCollection.Count);
             base.SendCollisionUpdate(CollisionCollection);
 
-            // The collisionCollection structure is passed around in the simulator.
+            // The CollisionCollection instance is passed around in the simulator.
             // Make sure we don't have a handle to that one and that a new one is used for next time.
+            //    This fixes an interesting 'gotcha'. If we call CollisionCollection.Clear() here, 
+            //    a race condition is created for the other users of this instance.
             CollisionCollection = new CollisionEventUpdate();
         }
         return ret;
@@ -229,7 +253,8 @@ public abstract class BSPhysObject : PhysicsActor
 
             PhysicsScene.TaintedObject(TypeName+".SubscribeEvents", delegate()
             {
-                CurrentCollisionFlags = BulletSimAPI.AddToCollisionFlags2(PhysBody.ptr, CollisionFlags.BS_SUBSCRIBE_COLLISION_EVENTS);
+                if (PhysBody.HasPhysicalBody)
+                    CurrentCollisionFlags = BulletSimAPI.AddToCollisionFlags2(PhysBody.ptr, CollisionFlags.BS_SUBSCRIBE_COLLISION_EVENTS);
             });
         }
         else
@@ -243,7 +268,9 @@ public abstract class BSPhysObject : PhysicsActor
         SubscribedEventsMs = 0;
         PhysicsScene.TaintedObject(TypeName+".UnSubscribeEvents", delegate()
         {
-            CurrentCollisionFlags = BulletSimAPI.RemoveFromCollisionFlags2(PhysBody.ptr, CollisionFlags.BS_SUBSCRIBE_COLLISION_EVENTS);
+            // Make sure there is a body there because sometimes destruction happens in an un-ideal order.
+            if (PhysBody.HasPhysicalBody)
+                CurrentCollisionFlags = BulletSimAPI.RemoveFromCollisionFlags2(PhysBody.ptr, CollisionFlags.BS_SUBSCRIBE_COLLISION_EVENTS);
         });
     }
     // Return 'true' if the simulator wants collision events
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
index 2b3fa25..68a0db6 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
@@ -45,7 +45,6 @@ public sealed class BSPrim : BSPhysObject
     private static readonly string LogHeader = "[BULLETS PRIM]";
 
     // _size is what the user passed. Scale is what we pass to the physics engine with the mesh.
-    // Often Scale is unity because the meshmerizer will apply _size when creating the mesh.
     private OMV.Vector3 _size;  // the multiplier for each mesh dimension as passed by the user
 
     private bool _grabbed;
@@ -93,7 +92,7 @@ public sealed class BSPrim : BSPhysObject
         _physicsActorType = (int)ActorTypes.Prim;
         _position = pos;
         _size = size;
-        Scale = size;   // the scale will be set by CreateGeom depending on object type
+        Scale = size;   // prims are the size the user wants them to be (different for BSCharactes).
         _orientation = rotation;
         _buoyancy = 1f;
         _velocity = OMV.Vector3.Zero;
@@ -101,15 +100,20 @@ public sealed class BSPrim : BSPhysObject
         BaseShape = pbs;
         _isPhysical = pisPhysical;
         _isVolumeDetect = false;
-        _friction = PhysicsScene.Params.defaultFriction;  // TODO: compute based on object material
-        _density = PhysicsScene.Params.defaultDensity;    // TODO: compute based on object material
+
+        // Someday set default attributes based on the material but, for now, we don't know the prim material yet.
+        // MaterialAttributes primMat = BSMaterials.GetAttributes(Material, pisPhysical);
+        _density = PhysicsScene.Params.defaultDensity;
+        _friction = PhysicsScene.Params.defaultFriction;
         _restitution = PhysicsScene.Params.defaultRestitution;
+
         _vehicle = new BSDynamics(PhysicsScene, this);            // add vehicleness
+
         _mass = CalculateMass();
 
         // No body or shape yet
-        PhysBody = new BulletBody(LocalID, IntPtr.Zero);
-        PhysShape = new BulletShape(IntPtr.Zero);
+        PhysBody = new BulletBody(LocalID);
+        PhysShape = new BulletShape();
 
         DetailLog("{0},BSPrim.constructor,call", LocalID);
         // do the actual object creation at taint time
@@ -143,7 +147,9 @@ public sealed class BSPrim : BSPhysObject
             DetailLog("{0},BSPrim.Destroy,taint,", LocalID);
             // If there are physical body and shape, release my use of same.
             PhysicsScene.Shapes.DereferenceBody(PhysBody, true, null);
+            PhysBody.Clear();
             PhysicsScene.Shapes.DereferenceShape(PhysShape, true, null);
+            PhysShape.Clear();
         });
     }
 
@@ -157,12 +163,10 @@ public sealed class BSPrim : BSPhysObject
             // We presume the scale and size are the same. If scale must be changed for
             //     the physical shape, that is done when the geometry is built.
             _size = value;
+            Scale = _size;
             ForceBodyShapeRebuild(false);
         }
     }
-    // Scale is what we set in the physics engine. It is different than 'size' in that
-    //     'size' can be encorporated into the mesh. In that case, the scale is <1,1,1>.
-    public override OMV.Vector3 Scale { get; set; }
 
     public override PrimitiveBaseShape Shape {
         set {
@@ -189,13 +193,17 @@ public sealed class BSPrim : BSPhysObject
         }
     }
     public override bool Selected {
-        set {
-            _isSelected = value;
-            PhysicsScene.TaintedObject("BSPrim.setSelected", delegate()
+        set
+        {
+            if (value != _isSelected)
             {
-                DetailLog("{0},BSPrim.selected,taint,selected={1}", LocalID, _isSelected);
-                SetObjectDynamic(false);
-            });
+                _isSelected = value;
+                PhysicsScene.TaintedObject("BSPrim.setSelected", delegate()
+                {
+                    DetailLog("{0},BSPrim.selected,taint,selected={1}", LocalID, _isSelected);
+                    SetObjectDynamic(false);
+                });
+            }
         }
     }
     public override void CrossingFailure() { return; }
@@ -244,7 +252,8 @@ public sealed class BSPrim : BSPhysObject
         // Zero some other properties in the physics engine
         PhysicsScene.TaintedObject(inTaintTime, "BSPrim.ZeroMotion", delegate()
         {
-            BulletSimAPI.ClearAllForces2(PhysBody.ptr);
+            if (PhysBody.HasPhysicalBody)
+                BulletSimAPI.ClearAllForces2(PhysBody.ptr);
         });
     }
     public override void ZeroAngularMotion(bool inTaintTime)
@@ -253,8 +262,12 @@ public sealed class BSPrim : BSPhysObject
         // Zero some other properties in the physics engine
         PhysicsScene.TaintedObject(inTaintTime, "BSPrim.ZeroMotion", delegate()
         {
-            BulletSimAPI.SetInterpolationAngularVelocity2(PhysBody.ptr, OMV.Vector3.Zero);
-            BulletSimAPI.SetAngularVelocity2(PhysBody.ptr, OMV.Vector3.Zero);
+            // DetailLog("{0},BSPrim.ZeroAngularMotion,call,rotVel={1}", LocalID, _rotationalVelocity);
+            if (PhysBody.HasPhysicalBody)
+            {
+                BulletSimAPI.SetInterpolationAngularVelocity2(PhysBody.ptr, _rotationalVelocity);
+                BulletSimAPI.SetAngularVelocity2(PhysBody.ptr, _rotationalVelocity);
+            }
         });
     }
 
@@ -271,9 +284,12 @@ public sealed class BSPrim : BSPhysObject
     }
     public override OMV.Vector3 Position {
         get {
+            /* NOTE: this refetch is not necessary. The simulator knows about linkset children
+             *    and does not fetch this position info for children. Thus this is commented out.
             // child prims move around based on their parent. Need to get the latest location
             if (!Linkset.IsRoot(this))
-                _position = Linkset.Position(this);
+                _position = Linkset.PositionGet(this);
+            */
 
             // don't do the GetObjectPosition for root elements because this function is called a zillion times.
             // _position = BulletSimAPI.GetObjectPosition2(PhysicsScene.World.ptr, BSBody.ptr);
@@ -281,18 +297,22 @@ public sealed class BSPrim : BSPhysObject
         }
         set {
             // If the position must be forced into the physics engine, use ForcePosition.
+            // All positions are given in world positions.
             if (_position == value)
             {
+                DetailLog("{0},BSPrim.setPosition,taint,positionNotChanging,pos={1},orient={2}", LocalID, _position, _orientation);
                 return;
             }
             _position = value;
-            // TODO: what does it mean to set the position of a child prim?? Rebuild the constraint?
             PositionSanityCheck(false);
+
+            // A linkset might need to know if a component information changed.
+            Linkset.UpdateProperties(this, false);
+
             PhysicsScene.TaintedObject("BSPrim.setPosition", delegate()
             {
-                // DetailLog("{0},BSPrim.SetPosition,taint,pos={1},orient={2}", LocalID, _position, _orientation);
-                BulletSimAPI.SetTranslation2(PhysBody.ptr, _position, _orientation);
-                ActivateIfPhysical(false);
+                DetailLog("{0},BSPrim.SetPosition,taint,pos={1},orient={2}", LocalID, _position, _orientation);
+                ForcePosition = _position;
             });
         }
     }
@@ -303,9 +323,11 @@ public sealed class BSPrim : BSPhysObject
         }
         set {
             _position = value;
-            // PositionSanityCheck();   // Don't do this! Causes a loop and caller should know better.
-            BulletSimAPI.SetTranslation2(PhysBody.ptr, _position, _orientation);
-            ActivateIfPhysical(false);
+            if (PhysBody.HasPhysicalBody)
+            {
+                BulletSimAPI.SetTranslation2(PhysBody.ptr, _position, _orientation);
+                ActivateIfPhysical(false);
+            }
         }
     }
 
@@ -316,39 +338,46 @@ public sealed class BSPrim : BSPhysObject
     {
         bool ret = false;
 
+        if (!PhysicsScene.TerrainManager.IsWithinKnownTerrain(_position))
+        {
+            // The physical object is out of the known/simulated area.
+            // Upper levels of code will handle the transition to other areas so, for
+            //     the time, we just ignore the position.
+            return ret;
+        }
+
         float terrainHeight = PhysicsScene.TerrainManager.GetTerrainHeightAtXYZ(_position);
         OMV.Vector3 upForce = OMV.Vector3.Zero;
-        if (Position.Z < terrainHeight)
+        if (RawPosition.Z < terrainHeight)
         {
             DetailLog("{0},BSPrim.PositionAdjustUnderGround,call,pos={1},terrain={2}", LocalID, _position, terrainHeight);
             float targetHeight = terrainHeight + (Size.Z / 2f);
             // Upforce proportional to the distance away from the terrain. Correct the error in 1 sec.
-            upForce.Z = (terrainHeight - Position.Z) * 1f;
+            upForce.Z = (terrainHeight - RawPosition.Z) * 1f;
             ret = true;
         }
 
         if ((CurrentCollisionFlags & CollisionFlags.BS_FLOATS_ON_WATER) != 0)
         {
-            float waterHeight = PhysicsScene.GetWaterLevelAtXYZ(_position);
+            float waterHeight = PhysicsScene.TerrainManager.GetWaterLevelAtXYZ(_position);
             // TODO: a floating motor so object will bob in the water
-            if (Math.Abs(Position.Z - waterHeight) > 0.1f)
+            if (Math.Abs(RawPosition.Z - waterHeight) > 0.1f)
             {
                 // Upforce proportional to the distance away from the water. Correct the error in 1 sec.
-                upForce.Z = (waterHeight - Position.Z) * 1f;
+                upForce.Z = (waterHeight - RawPosition.Z) * 1f;
                 ret = true;
             }
         }
 
-        // TODO: check for out of bounds
-
         // The above code computes a force to apply to correct any out-of-bounds problems. Apply same.
+        // TODO: This should be intergrated with a geneal physics action mechanism.
+        // TODO: This should be moderated with PID'ness.
         if (ret)
         {
-            PhysicsScene.TaintedObject(inTaintTime, "BSPrim.PositionSanityCheck:belowTerrain", delegate()
-            {
-                // Apply upforce and overcome gravity.
-                ForceVelocity = ForceVelocity + upForce - PhysicsScene.DefaultGravity;
-            });
+            // Apply upforce and overcome gravity.
+            OMV.Vector3 correctionForce = upForce - PhysicsScene.DefaultGravity;
+            DetailLog("{0},BSPrim.PositionSanityCheck,applyForce,pos={1},upForce={2},correctionForce={3}", LocalID, _position, upForce, correctionForce);
+            AddForce(correctionForce, false, inTaintTime);
         }
         return ret;
     }
@@ -408,7 +437,8 @@ public sealed class BSPrim : BSPhysObject
             PhysicsScene.TaintedObject("BSPrim.setForce", delegate()
             {
                 // DetailLog("{0},BSPrim.setForce,taint,force={1}", LocalID, _force);
-                BulletSimAPI.SetObjectForce2(PhysBody.ptr, _force);
+                if (PhysBody.HasPhysicalBody)
+                    BulletSimAPI.SetObjectForce2(PhysBody.ptr, _force);
             });
         }
     }
@@ -502,15 +532,18 @@ public sealed class BSPrim : BSPhysObject
             PhysicsScene.TaintedObject("BSPrim.setVelocity", delegate()
             {
                 // DetailLog("{0},BSPrim.SetVelocity,taint,vel={1}", LocalID, _velocity);
-                BulletSimAPI.SetLinearVelocity2(PhysBody.ptr, _velocity);
+                ForceVelocity = _velocity;
             });
         }
     }
     public override OMV.Vector3 ForceVelocity {
         get { return _velocity; }
         set {
+            PhysicsScene.AssertInTaintTime("BSPrim.ForceVelocity");
+
             _velocity = value;
-            BulletSimAPI.SetLinearVelocity2(PhysBody.ptr, _velocity);
+            if (PhysBody.HasPhysicalBody)
+                BulletSimAPI.SetLinearVelocity2(PhysBody.ptr, _velocity);
         }
     }
     public override OMV.Vector3 Torque {
@@ -537,23 +570,32 @@ public sealed class BSPrim : BSPhysObject
     }
     public override OMV.Quaternion Orientation {
         get {
+            /* NOTE: this refetch is not necessary. The simulator knows about linkset children
+             *    and does not fetch this position info for children. Thus this is commented out.
             // Children move around because tied to parent. Get a fresh value.
             if (!Linkset.IsRoot(this))
             {
-                _orientation = Linkset.Orientation(this);
+                _orientation = Linkset.OrientationGet(this);
             }
+             */
             return _orientation;
         }
         set {
             if (_orientation == value)
                 return;
             _orientation = value;
-            // TODO: what does it mean if a child in a linkset changes its orientation? Rebuild the constraint?
+
+            // A linkset might need to know if a component information changed.
+            Linkset.UpdateProperties(this, false);
+
             PhysicsScene.TaintedObject("BSPrim.setOrientation", delegate()
             {
-                // _position = BulletSimAPI.GetObjectPosition2(PhysicsScene.World.ptr, BSBody.ptr);
-                // DetailLog("{0},BSPrim.setOrientation,taint,pos={1},orient={2}", LocalID, _position, _orientation);
-                BulletSimAPI.SetTranslation2(PhysBody.ptr, _position, _orientation);
+                if (PhysBody.HasPhysicalBody)
+                {
+                    // _position = BulletSimAPI.GetObjectPosition2(PhysicsScene.World.ptr, BSBody.ptr);
+                    // DetailLog("{0},BSPrim.setOrientation,taint,pos={1},orient={2}", LocalID, _position, _orientation);
+                    BulletSimAPI.SetTranslation2(PhysBody.ptr, _position, _orientation);
+                }
             });
         }
     }
@@ -644,10 +686,7 @@ public sealed class BSPrim : BSPhysObject
         BulletSimAPI.UpdateSingleAabb2(PhysicsScene.World.ptr, PhysBody.ptr);
 
         // Collision filter can be set only when the object is in the world
-        if (PhysBody.collisionFilter != 0 || PhysBody.collisionMask != 0)
-        {
-            BulletSimAPI.SetCollisionFilterMask2(PhysBody.ptr, (uint)PhysBody.collisionFilter, (uint)PhysBody.collisionMask);
-        }
+        PhysBody.ApplyCollisionMask();
 
         // Recompute any linkset parameters.
         // When going from non-physical to physical, this re-enables the constraints that
@@ -672,8 +711,12 @@ public sealed class BSPrim : BSPhysObject
             CurrentCollisionFlags = BulletSimAPI.AddToCollisionFlags2(PhysBody.ptr, CollisionFlags.CF_STATIC_OBJECT);
             // Stop all movement
             ZeroMotion(true);
-            // Center of mass is at the center of the object
-            // DEBUG DEBUG BulletSimAPI.SetCenterOfMassByPosRot2(Linkset.LinksetRoot.PhysBody.ptr, _position, _orientation);
+
+            // Set various physical properties so other object interact properly
+            MaterialAttributes matAttrib = BSMaterials.GetAttributes(Material, false);
+            BulletSimAPI.SetFriction2(PhysBody.ptr, matAttrib.friction);
+            BulletSimAPI.SetRestitution2(PhysBody.ptr, matAttrib.restitution);
+
             // Mass is zero which disables a bunch of physics stuff in Bullet
             UpdatePhysicalMassProperties(0f);
             // Set collision detection parameters
@@ -682,24 +725,27 @@ public sealed class BSPrim : BSPhysObject
                 BulletSimAPI.SetCcdMotionThreshold2(PhysBody.ptr, PhysicsScene.Params.ccdMotionThreshold);
                 BulletSimAPI.SetCcdSweptSphereRadius2(PhysBody.ptr, PhysicsScene.Params.ccdSweptSphereRadius);
             }
-            // There can be special things needed for implementing linksets
-            Linkset.MakeStatic(this);
+
             // The activation state is 'disabled' so Bullet will not try to act on it.
-            BulletSimAPI.ForceActivationState2(PhysBody.ptr, ActivationState.DISABLE_SIMULATION);
+            // BulletSimAPI.ForceActivationState2(PhysBody.ptr, ActivationState.DISABLE_SIMULATION);
             // Start it out sleeping and physical actions could wake it up.
-            // BulletSimAPI.ForceActivationState2(BSBody.ptr, ActivationState.ISLAND_SLEEPING);
+            BulletSimAPI.ForceActivationState2(PhysBody.ptr, ActivationState.ISLAND_SLEEPING);
+
+            // This collides like a static object
+            PhysBody.collisionType = CollisionType.Static;
 
-            PhysBody.collisionFilter = CollisionFilterGroups.StaticObjectFilter;
-            PhysBody.collisionMask = CollisionFilterGroups.StaticObjectMask;
+            // There can be special things needed for implementing linksets
+            Linkset.MakeStatic(this);
         }
         else
         {
             // Not a Bullet static object
             CurrentCollisionFlags = BulletSimAPI.RemoveFromCollisionFlags2(PhysBody.ptr, CollisionFlags.CF_STATIC_OBJECT);
 
-            // Set various physical properties so internal dynamic properties will get computed correctly as they are set
-            BulletSimAPI.SetFriction2(PhysBody.ptr, PhysicsScene.Params.defaultFriction);
-            BulletSimAPI.SetRestitution2(PhysBody.ptr, PhysicsScene.Params.defaultRestitution);
+            // Set various physical properties so other object interact properly
+            MaterialAttributes matAttrib = BSMaterials.GetAttributes(Material, true);
+            BulletSimAPI.SetFriction2(PhysBody.ptr, matAttrib.friction);
+            BulletSimAPI.SetRestitution2(PhysBody.ptr, matAttrib.restitution);
 
             // per http://www.bulletphysics.org/Bullet/phpBB3/viewtopic.php?t=3382
             // Since this can be called multiple times, only zero forces when becoming physical
@@ -727,16 +773,15 @@ public sealed class BSPrim : BSPhysObject
             BulletSimAPI.SetSleepingThresholds2(PhysBody.ptr, PhysicsScene.Params.linearSleepingThreshold, PhysicsScene.Params.angularSleepingThreshold);
             BulletSimAPI.SetContactProcessingThreshold2(PhysBody.ptr, PhysicsScene.Params.contactProcessingThreshold);
 
-            // There might be special things needed for implementing linksets.
-            Linkset.MakeDynamic(this);
+            // This collides like an object.
+            PhysBody.collisionType = CollisionType.Dynamic;
 
             // Force activation of the object so Bullet will act on it.
             // Must do the ForceActivationState2() to overcome the DISABLE_SIMULATION from static objects.
             BulletSimAPI.ForceActivationState2(PhysBody.ptr, ActivationState.ACTIVE_TAG);
-            // BulletSimAPI.Activate2(BSBody.ptr, true);
 
-            PhysBody.collisionFilter = CollisionFilterGroups.ObjectFilter;
-            PhysBody.collisionMask = CollisionFilterGroups.ObjectMask;
+            // There might be special things needed for implementing linksets.
+            Linkset.MakeDynamic(this);
         }
     }
 
@@ -763,8 +808,9 @@ public sealed class BSPrim : BSPhysObject
                 m_log.ErrorFormat("{0} MakeSolid: physical body of wrong type for non-solidness. id={1}, type={2}", LogHeader, LocalID, bodyType);
             }
             CurrentCollisionFlags = BulletSimAPI.AddToCollisionFlags2(PhysBody.ptr, CollisionFlags.CF_NO_CONTACT_RESPONSE);
-            PhysBody.collisionFilter = CollisionFilterGroups.VolumeDetectFilter;
-            PhysBody.collisionMask = CollisionFilterGroups.VolumeDetectMask;
+
+            // Change collision info from a static object to a ghosty collision object
+            PhysBody.collisionType = CollisionType.VolumeDetect;
         }
     }
 
@@ -839,15 +885,6 @@ public sealed class BSPrim : BSPhysObject
     }
     public override OMV.Vector3 RotationalVelocity {
         get {
-            /*
-            OMV.Vector3 pv = OMV.Vector3.Zero;
-            // if close to zero, report zero
-            // This is copied from ODE but I'm not sure why it returns zero but doesn't
-            //    zero the property in the physics engine.
-            if (_rotationalVelocity.ApproxEquals(pv, 0.2f))
-                return pv;
-             */
-
             return _rotationalVelocity;
         }
         set {
@@ -856,7 +893,8 @@ public sealed class BSPrim : BSPhysObject
             PhysicsScene.TaintedObject("BSPrim.setRotationalVelocity", delegate()
             {
                 DetailLog("{0},BSPrim.SetRotationalVel,taint,rotvel={1}", LocalID, _rotationalVelocity);
-                BulletSimAPI.SetAngularVelocity2(PhysBody.ptr, _rotationalVelocity);
+                if (PhysBody.HasPhysicalBody)
+                    BulletSimAPI.SetAngularVelocity2(PhysBody.ptr, _rotationalVelocity);
             });
         }
     }
@@ -891,8 +929,11 @@ public sealed class BSPrim : BSPhysObject
             _buoyancy = value;
             // DetailLog("{0},BSPrim.setForceBuoyancy,taint,buoy={1}", LocalID, _buoyancy);
             // Buoyancy is faked by changing the gravity applied to the object
-            float grav = PhysicsScene.Params.gravity * (1f - _buoyancy);
-            BulletSimAPI.SetGravity2(PhysBody.ptr, new OMV.Vector3(0f, 0f, grav));
+            if (PhysBody.HasPhysicalBody)
+            {
+                float grav = PhysicsScene.Params.gravity * (1f - _buoyancy);
+                BulletSimAPI.SetGravity2(PhysBody.ptr, new OMV.Vector3(0f, 0f, grav));
+            }
         }
     }
 
@@ -960,7 +1001,8 @@ public sealed class BSPrim : BSPhysObject
             }
             DetailLog("{0},BSPrim.AddForce,taint,force={1}", LocalID, fSum);
             if (fSum != OMV.Vector3.Zero)
-                BulletSimAPI.ApplyCentralForce2(PhysBody.ptr, fSum);
+                if (PhysBody.HasPhysicalBody)
+                    BulletSimAPI.ApplyCentralForce2(PhysBody.ptr, fSum);
         });
     }
 
@@ -971,7 +1013,8 @@ public sealed class BSPrim : BSPhysObject
         PhysicsScene.TaintedObject(inTaintTime, "BSPrim.ApplyForceImpulse", delegate()
         {
             DetailLog("{0},BSPrim.ApplyForceImpulse,taint,tImpulse={1}", LocalID, applyImpulse);
-            BulletSimAPI.ApplyCentralImpulse2(PhysBody.ptr, applyImpulse);
+            if (PhysBody.HasPhysicalBody)
+                BulletSimAPI.ApplyCentralImpulse2(PhysBody.ptr, applyImpulse);
         });
     }
 
@@ -1007,18 +1050,23 @@ public sealed class BSPrim : BSPhysObject
             DetailLog("{0},BSPrim.AddAngularForce,taint,aForce={1}", LocalID, fSum);
             if (fSum != OMV.Vector3.Zero)
             {
-                BulletSimAPI.ApplyTorque2(PhysBody.ptr, fSum);
+                if (PhysBody.HasPhysicalBody)
+                    BulletSimAPI.ApplyTorque2(PhysBody.ptr, fSum);
                 _torque = fSum;
             }
         });
     }
     // A torque impulse.
+    // ApplyTorqueImpulse adds torque directly to the angularVelocity.
+    // AddAngularForce accumulates the force and applied it to the angular velocity all at once.
+    // Computed as: angularVelocity += impulse * inertia;
     public void ApplyTorqueImpulse(OMV.Vector3 impulse, bool inTaintTime)
     {
         OMV.Vector3 applyImpulse = impulse;
         PhysicsScene.TaintedObject(inTaintTime, "BSPrim.ApplyTorqueImpulse", delegate()
         {
-            BulletSimAPI.ApplyTorqueImpulse2(PhysBody.ptr, applyImpulse);
+            if (PhysBody.HasPhysicalBody)
+                BulletSimAPI.ApplyTorqueImpulse2(PhysBody.ptr, applyImpulse);
         });
     }
 
@@ -1326,7 +1374,7 @@ public sealed class BSPrim : BSPhysObject
     // Rebuild the geometry and object.
     // This is called when the shape changes so we need to recreate the mesh/hull.
     // Called at taint-time!!!
-    private void CreateGeomAndObject(bool forceRebuild)
+    public void CreateGeomAndObject(bool forceRebuild)
     {
         // If this prim is part of a linkset, we must remove and restore the physical
         //    links if the body is rebuilt.
@@ -1336,12 +1384,11 @@ public sealed class BSPrim : BSPhysObject
         // Create the correct physical representation for this type of object.
         // Updates PhysBody and PhysShape with the new information.
         // Ignore 'forceRebuild'. This routine makes the right choices and changes of necessary.
-        // Returns 'true' if either the body or the shape was changed.
         PhysicsScene.Shapes.GetBodyAndShape(false, PhysicsScene.World, this, null, delegate(BulletBody dBody)
         {
             // Called if the current prim body is about to be destroyed.
             // Remove all the physical dependencies on the old body.
-            // (Maybe someday make the changing of BSShape an event handled by BSLinkset.)
+            // (Maybe someday make the changing of BSShape an event to be subscribed to by BSLinkset, ...)
             needToRestoreLinkset = Linkset.RemoveBodyDependencies(this);
             needToRestoreVehicle = _vehicle.RemoveBodyDependencies(this);
         });
@@ -1381,54 +1428,16 @@ public sealed class BSPrim : BSPhysObject
 
     public override void UpdateProperties(EntityProperties entprop)
     {
-        /*
-        UpdatedProperties changed = 0;
-        // assign to the local variables so the normal set action does not happen
-        // if (_position != entprop.Position)
-        if (!_position.ApproxEquals(entprop.Position, POSITION_TOLERANCE))
-        {
-            _position = entprop.Position;
-            changed |= UpdatedProperties.Position;
-        }
-        // if (_orientation != entprop.Rotation)
-        if (!_orientation.ApproxEquals(entprop.Rotation, ROTATION_TOLERANCE))
-        {
-            _orientation = entprop.Rotation;
-            changed |= UpdatedProperties.Rotation;
-        }
-        // if (_velocity != entprop.Velocity)
-        if (!_velocity.ApproxEquals(entprop.Velocity, VELOCITY_TOLERANCE))
-        {
-            _velocity = entprop.Velocity;
-            changed |= UpdatedProperties.Velocity;
-        }
-        // if (_acceleration != entprop.Acceleration)
-        if (!_acceleration.ApproxEquals(entprop.Acceleration, ACCELERATION_TOLERANCE))
-        {
-            _acceleration = entprop.Acceleration;
-            changed |= UpdatedProperties.Acceleration;
-        }
-        // if (_rotationalVelocity != entprop.RotationalVelocity)
-        if (!_rotationalVelocity.ApproxEquals(entprop.RotationalVelocity, ROTATIONAL_VELOCITY_TOLERANCE))
-        {
-            _rotationalVelocity = entprop.RotationalVelocity;
-            changed |= UpdatedProperties.RotationalVel;
-        }
-        if (changed != 0)
+        // Updates only for individual prims and for the root object of a linkset.
+        if (Linkset.IsRoot(this))
         {
-            // Only update the position of single objects and linkset roots
-            if (Linkset.IsRoot(this))
+            // A temporary kludge to suppress the rotational effects introduced on vehicles by Bullet
+            // TODO: handle physics introduced by Bullet with computed vehicle physics.
+            if (_vehicle.IsActive)
             {
-                base.RequestPhysicsterseUpdate();
+                entprop.RotationalVelocity = OMV.Vector3.Zero;
             }
-        }
-        */
 
-        // Don't check for damping here -- it's done in BulletSim and SceneObjectPart.
-
-        // Updates only for individual prims and for the root object of a linkset.
-        if (Linkset.IsRoot(this))
-        {
             // Assign directly to the local variables so the normal set action does not happen
             _position = entprop.Position;
             _orientation = entprop.Rotation;
@@ -1437,21 +1446,19 @@ public sealed class BSPrim : BSPhysObject
             _rotationalVelocity = entprop.RotationalVelocity;
 
             // The sanity check can change the velocity and/or position.
-            if (PositionSanityCheck(true))
+            if (IsPhysical && PositionSanityCheck(true))
             {
                 entprop.Position = _position;
                 entprop.Velocity = _velocity;
             }
 
-            // remember the current and last set values
-            LastEntityProperties = CurrentEntityProperties;
-            CurrentEntityProperties = entprop;
-
-            OMV.Vector3 direction = OMV.Vector3.UnitX * _orientation;
+            OMV.Vector3 direction = OMV.Vector3.UnitX * _orientation;   // DEBUG DEBUG DEBUG
             DetailLog("{0},BSPrim.UpdateProperties,call,pos={1},orient={2},dir={3},vel={4},rotVel={5}",
                     LocalID, _position, _orientation, direction, _velocity, _rotationalVelocity);
 
-            // BulletSimAPI.DumpRigidBody2(PhysicsScene.World.ptr, BSBody.ptr);   // DEBUG DEBUG DEBUG
+            // remember the current and last set values
+            LastEntityProperties = CurrentEntityProperties;
+            CurrentEntityProperties = entprop;
 
             base.RequestPhysicsterseUpdate();
         }
@@ -1466,7 +1473,7 @@ public sealed class BSPrim : BSPhysObject
              */
 
         // The linkset implimentation might want to know about this.
-        Linkset.UpdateProperties(this);
+        Linkset.UpdateProperties(this, true);
     }
 }
 }
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs b/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
index 27a78d1..2ca4912 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
@@ -39,23 +39,10 @@ using log4net;
 using OpenMetaverse;
 
 // TODOs for BulletSim (for BSScene, BSPrim, BSCharacter and BulletSim)
-// Test sculpties (verified that they don't work)
-// Compute physics FPS reasonably
 // Based on material, set density and friction
-// Don't use constraints in linksets of non-physical objects. Means having to move children manually.
-// Four states of prim: Physical, regular, phantom and selected. Are we modeling these correctly?
-//     In SL one can set both physical and phantom (gravity, does not effect others, makes collisions with ground)
-//     At the moment, physical and phantom causes object to drop through the terrain
-// Physical phantom objects and related typing (collision options )
-// Check out llVolumeDetect. Must do something for that.
-// Use collision masks for collision with terrain and phantom objects
 // More efficient memory usage when passing hull information from BSPrim to BulletSim
-// Should prim.link() and prim.delink() membership checking happen at taint time?
-// Mesh sharing. Use meshHash to tell if we already have a hull of that shape and only create once.
 // Do attachments need to be handled separately? Need collision events. Do not collide with VolumeDetect
 // Implement LockAngularMotion
-// Decide if clearing forces is the right thing to do when setting position (BulletSim::SetObjectTranslation)
-// Remove mesh and Hull stuff. Use mesh passed to bullet and use convexdecom from bullet.
 // Add PID movement operations. What does ScenePresence.MoveToTarget do?
 // Check terrain size. 128 or 127?
 // Raycast
@@ -109,6 +96,19 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
     public long SimulationStep { get { return m_simulationStep; } }
     private int m_taintsToProcessPerStep;
 
+    // Avatar parameters
+    public float ParamAvatarFriction { get; private set; }
+    public float ParamAvatarStandingFriction { get; private set; }
+    public float ParamAvatarDensity { get; private set; }
+    public float ParamAvatarRestitution { get; private set; }
+    public float ParamAvatarCapsuleWidth { get; private set; }
+    public float ParamAvatarCapsuleDepth { get; private set; }
+    public float ParamAvatarCapsuleHeight { get; private set; }
+        public float ParamAvatarContactProcessingThreshold { get; private set; }
+
+    public delegate void PreStepAction(float timeStep);
+    public event PreStepAction BeforeStep;
+
     // A value of the time now so all the collision and update routines do not have to get their own
     // Set to 'now' just before all the prims and actors are called for collisions and updates
     public int SimulationNowTime { get; private set; }
@@ -140,7 +140,7 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
     public const uint GROUNDPLANE_ID = 1;
     public const uint CHILDTERRAIN_ID = 2;  // Terrain allocated based on our mega-prim childre start here
 
-    private float m_waterLevel;
+    public float SimpleWaterLevel { get; set; }
     public BSTerrainManager TerrainManager { get; private set; }
 
     public ConfigurationParameters Params
@@ -195,8 +195,10 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
     private string m_physicsLoggingDir;
     private string m_physicsLoggingPrefix;
     private int m_physicsLoggingFileMinutes;
+    private bool m_physicsLoggingDoFlush;
     // 'true' of the vehicle code is to log lots of details
     public bool VehicleLoggingEnabled { get; private set; }
+    public bool VehiclePhysicalLoggingEnabled { get; private set; }
 
     #region Construction and Initialization
     public BSScene(string identifier)
@@ -234,6 +236,7 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
         if (m_physicsLoggingEnabled)
         {
             PhysicsLogging = new Logging.LogWriter(m_physicsLoggingDir, m_physicsLoggingPrefix, m_physicsLoggingFileMinutes);
+            PhysicsLogging.ErrorLogger = m_log; // for DEBUG. Let's the logger output error messages.
         }
         else
         {
@@ -302,12 +305,22 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
                 m_physicsLoggingDir = pConfig.GetString("PhysicsLoggingDir", ".");
                 m_physicsLoggingPrefix = pConfig.GetString("PhysicsLoggingPrefix", "physics-%REGIONNAME%-");
                 m_physicsLoggingFileMinutes = pConfig.GetInt("PhysicsLoggingFileMinutes", 5);
+                m_physicsLoggingDoFlush = pConfig.GetBoolean("PhysicsLoggingDoFlush", false);
                 // Very detailed logging for vehicle debugging
                 VehicleLoggingEnabled = pConfig.GetBoolean("VehicleLoggingEnabled", false);
+                VehiclePhysicalLoggingEnabled = pConfig.GetBoolean("VehiclePhysicalLoggingEnabled", false);
 
                 // Do any replacements in the parameters
                 m_physicsLoggingPrefix = m_physicsLoggingPrefix.Replace("%REGIONNAME%", RegionName);
             }
+
+            // The material characteristics.
+            BSMaterials.InitializeFromDefaults(Params);
+            if (pConfig != null)
+            {
+                // Let the user add new and interesting material property values.
+                BSMaterials.InitializefromParameters(pConfig);
+            }
         }
     }
 
@@ -345,8 +358,6 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
         // make sure no stepping happens while we're deleting stuff
         m_initialized = false;
 
-        TerrainManager.ReleaseGroundPlaneAndTerrain();
-
         foreach (KeyValuePair<uint, BSPhysObject> kvp in PhysObjects)
         {
             kvp.Value.Destroy();
@@ -366,6 +377,13 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
             Shapes = null;
         }
 
+        if (TerrainManager != null)
+        {
+            TerrainManager.ReleaseGroundPlaneAndTerrain();
+            TerrainManager.Dispose();
+            TerrainManager = null;
+        }
+
         // Anything left in the unmanaged code should be cleaned out
         BulletSimAPI.Shutdown2(World.ptr);
 
@@ -490,8 +508,10 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
         ProcessTaints();
 
         // Some of the prims operate with special vehicle properties
-        ProcessVehicles(timeStep);
-        ProcessTaints();    // the vehicles might have added taints
+        DoPreStepActions(timeStep);
+
+        // the prestep actions might have added taints
+        ProcessTaints();
 
         // step the physical world one interval
         m_simulationStep++;
@@ -499,16 +519,17 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
 
         try
         {
-            if (VehicleLoggingEnabled) DumpVehicles();  // DEBUG
+            if (VehiclePhysicalLoggingEnabled) DumpVehicles();  // DEBUG
             if (PhysicsLogging.Enabled) beforeTime = Util.EnvironmentTickCount();
 
             numSubSteps = BulletSimAPI.PhysicsStep2(World.ptr, timeStep, m_maxSubSteps, m_fixedTimeStep,
                         out updatedEntityCount, out updatedEntitiesPtr, out collidersCount, out collidersPtr);
 
             if (PhysicsLogging.Enabled) simTime = Util.EnvironmentTickCountSubtract(beforeTime);
-            DetailLog("{0},Simulate,call, frame={1}, nTaints={2}, simTime={3}, substeps={4}, updates={5}, colliders={6}",
-                        DetailLogZero, m_simulationStep, numTaints, simTime, numSubSteps, updatedEntityCount, collidersCount);
-            if (VehicleLoggingEnabled) DumpVehicles();  // DEBUG
+            DetailLog("{0},Simulate,call, frame={1}, nTaints={2}, simTime={3}, substeps={4}, updates={5}, colliders={6}, objWColl={7}",
+                                    DetailLogZero, m_simulationStep, numTaints, simTime, numSubSteps, 
+                                    updatedEntityCount, collidersCount, ObjectsWithCollisions.Count);
+            if (VehiclePhysicalLoggingEnabled) DumpVehicles();  // DEBUG
         }
         catch (Exception e)
         {
@@ -520,9 +541,9 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
             collidersCount = 0;
         }
 
-        // Don't have to use the pointers passed back since we know it is the same pinned memory we passed in
+        // Don't have to use the pointers passed back since we know it is the same pinned memory we passed in.
 
-        // Get a value for 'now' so all the collision and update routines don't have to get their own
+        // Get a value for 'now' so all the collision and update routines don't have to get their own.
         SimulationNowTime = Util.EnvironmentTickCount();
 
         // If there were collisions, process them by sending the event to the prim.
@@ -562,12 +583,16 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
 
         // Objects that are done colliding are removed from the ObjectsWithCollisions list.
         // Not done above because it is inside an iteration of ObjectWithCollisions.
+        // This complex collision processing is required to create an empty collision
+        //     event call after all collisions have happened on an object. This enables
+        //     the simulator to generate the 'collision end' event.
         if (ObjectsWithNoMoreCollisions.Count > 0)
         {
             foreach (BSPhysObject po in ObjectsWithNoMoreCollisions)
                 ObjectsWithCollisions.Remove(po);
             ObjectsWithNoMoreCollisions.Clear();
         }
+        // Done with collisions.
 
         // If any of the objects had updated properties, tell the object it has been changed by the physics engine
         if (updatedEntityCount > 0)
@@ -585,15 +610,14 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
 
         ProcessPostStepTaints();
 
-        // This causes the unmanaged code to output ALL the values found in ALL the objects in the world.
+        // The following causes the unmanaged code to output ALL the values found in ALL the objects in the world.
         // Only enable this in a limited test world with few objects.
         // BulletSimAPI.DumpAllInfo2(World.ptr);    // DEBUG DEBUG DEBUG
 
         // The physics engine returns the number of milliseconds it simulated this call.
         // These are summed and normalized to one second and divided by 1000 to give the reported physics FPS.
-        // We multiply by 55 to give a recognizable running rate (55 or less).
-        return numSubSteps * m_fixedTimeStep * 1000 * 55;
-        // return timeStep * 1000 * 55;
+        // Multiply by 55 to give a nominal frame rate of 55.
+        return (float)numSubSteps * m_fixedTimeStep * 1000f * 55f;
     }
 
     // Something has collided
@@ -639,12 +663,7 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
 
     public override void SetWaterLevel(float baseheight)
     {
-        m_waterLevel = baseheight;
-    }
-    // Someday....
-    public float GetWaterLevelAtXYZ(Vector3 loc)
-    {
-        return m_waterLevel;
+        SimpleWaterLevel = baseheight;
     }
 
     public override void DeleteTerrain()
@@ -915,6 +934,16 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
         }
     }
 
+    private void DoPreStepActions(float timeStep)
+    {
+        ProcessVehicles(timeStep);
+
+        PreStepAction actions = BeforeStep;
+        if (actions != null)
+            actions(timeStep);
+
+    }
+
     // Some prims have extra vehicle actions
     // Called at taint time!
     private void ProcessVehicles(float timeStep)
@@ -979,6 +1008,8 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
     //          Should handle fetching the right type from the ini file and converting it.
     //    -- a delegate for getting the value as a float
     //    -- a delegate for setting the value from a float
+    //    -- an optional delegate to update the value in the world. Most often used to
+    //          push the new value to an in-world object.
     //
     // The single letter parameters for the delegates are:
     //    s = BSScene
@@ -1069,7 +1100,7 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
             (s,p,l,v) => { s.PID_P = v; } ),
 
         new ParameterDefn("DefaultFriction", "Friction factor used on new objects",
-            0.5f,
+            0.2f,
             (s,cf,p,v) => { s.m_params[0].defaultFriction = cf.GetFloat(p, v); },
             (s) => { return s.m_params[0].defaultFriction; },
             (s,p,l,v) => { s.m_params[0].defaultFriction = v; } ),
@@ -1084,7 +1115,7 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
             (s) => { return s.m_params[0].defaultRestitution; },
             (s,p,l,v) => { s.m_params[0].defaultRestitution = v; } ),
         new ParameterDefn("CollisionMargin", "Margin around objects before collisions are calculated (must be zero!)",
-            0f,
+            0.04f,
             (s,cf,p,v) => { s.m_params[0].collisionMargin = cf.GetFloat(p, v); },
             (s) => { return s.m_params[0].collisionMargin; },
             (s,p,l,v) => { s.m_params[0].collisionMargin = v; } ),
@@ -1151,7 +1182,7 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
             (s) => { return s.m_params[0].terrainImplementation; },
             (s,p,l,v) => { s.m_params[0].terrainImplementation = v; } ),
         new ParameterDefn("TerrainFriction", "Factor to reduce movement against terrain surface" ,
-            0.5f,
+            0.3f,
             (s,cf,p,v) => { s.m_params[0].terrainFriction = cf.GetFloat(p, v); },
             (s) => { return s.m_params[0].terrainFriction; },
             (s,p,l,v) => { s.m_params[0].terrainFriction = v;  /* TODO: set on real terrain */} ),
@@ -1165,13 +1196,19 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
             (s,cf,p,v) => { s.m_params[0].terrainRestitution = cf.GetFloat(p, v); },
             (s) => { return s.m_params[0].terrainRestitution; },
             (s,p,l,v) => { s.m_params[0].terrainRestitution = v;  /* TODO: set on real terrain */ } ),
+        new ParameterDefn("TerrainCollisionMargin", "Margin where collision checking starts" ,
+            0.04f,
+            (s,cf,p,v) => { s.m_params[0].terrainCollisionMargin = cf.GetFloat(p, v); },
+            (s) => { return s.m_params[0].terrainCollisionMargin; },
+            (s,p,l,v) => { s.m_params[0].terrainCollisionMargin = v;  /* TODO: set on real terrain */ } ),
+
         new ParameterDefn("AvatarFriction", "Factor to reduce movement against an avatar. Changed on avatar recreation.",
             0.2f,
             (s,cf,p,v) => { s.m_params[0].avatarFriction = cf.GetFloat(p, v); },
             (s) => { return s.m_params[0].avatarFriction; },
             (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].avatarFriction, p, l, v); } ),
         new ParameterDefn("AvatarStandingFriction", "Avatar friction when standing. Changed on avatar recreation.",
-            10f,
+            10.0f,
             (s,cf,p,v) => { s.m_params[0].avatarStandingFriction = cf.GetFloat(p, v); },
             (s) => { return s.m_params[0].avatarStandingFriction; },
             (s,p,l,v) => { s.m_params[0].avatarStandingFriction = v; } ),
@@ -1206,6 +1243,11 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
             (s) => { return s.m_params[0].avatarContactProcessingThreshold; },
             (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].avatarContactProcessingThreshold, p, l, v); } ),
 
+        new ParameterDefn("VehicleAngularDamping", "Factor to damp vehicle angular movement per second (0.0 - 1.0)",
+            0.95f,
+            (s,cf,p,v) => { s.m_params[0].vehicleAngularDamping = cf.GetFloat(p, v); },
+            (s) => { return s.m_params[0].vehicleAngularDamping; },
+            (s,p,l,v) => { s.m_params[0].vehicleAngularDamping = v; } ),
 
             new ParameterDefn("MaxPersistantManifoldPoolSize", "Number of manifolds pooled (0 means default of 4096)",
             0f,
@@ -1487,7 +1529,7 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
     {
         PhysicsLogging.Write(msg, args);
         // Add the Flush() if debugging crashes. Gets all the messages written out.
-        // PhysicsLogging.Flush();
+        if (m_physicsLoggingDoFlush) PhysicsLogging.Flush();
     }
     // Used to fill in the LocalID when there isn't one. It's the correct number of characters.
     public const string DetailLogZero = "0000000000";
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSShapeCollection.cs b/OpenSim/Region/Physics/BulletSPlugin/BSShapeCollection.cs
index 892c34b..d6e2fe9 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSShapeCollection.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSShapeCollection.cs
@@ -65,9 +65,16 @@ public sealed class BSShapeCollection : IDisposable
     private Dictionary<System.UInt64, MeshDesc> Meshes = new Dictionary<System.UInt64, MeshDesc>();
     private Dictionary<System.UInt64, HullDesc> Hulls = new Dictionary<System.UInt64, HullDesc>();
 
+    private bool DDetail = false;
+
     public BSShapeCollection(BSScene physScene)
     {
         PhysicsScene = physScene;
+        // Set the next to 'true' for very detailed shape update detailed logging (detailed details?)
+        // While detailed debugging is still active, this is better than commenting out all the
+        //     DetailLog statements. When debugging slows down, this and the protected logging
+        //     statements can be commented/removed.
+        DDetail = true;
     }
 
     public void Dispose()
@@ -119,6 +126,11 @@ public sealed class BSShapeCollection : IDisposable
         return ret;
     }
 
+    public bool GetBodyAndShape(bool forceRebuild, BulletSim sim, BSPhysObject prim)
+    {
+        return GetBodyAndShape(forceRebuild, sim, prim, null, null);
+    }
+
     // Track another user of a body.
     // We presume the caller has allocated the body.
     // Bodies only have one user so the body is just put into the world if not already there.
@@ -126,13 +138,13 @@ public sealed class BSShapeCollection : IDisposable
     {
         lock (m_collectionActivityLock)
         {
-            DetailLog("{0},BSShapeCollection.ReferenceBody,newBody,body={1}", body.ID, body);
+            if (DDetail) DetailLog("{0},BSShapeCollection.ReferenceBody,newBody,body={1}", body.ID, body);
             PhysicsScene.TaintedObject(inTaintTime, "BSShapeCollection.ReferenceBody", delegate()
             {
                 if (!BulletSimAPI.IsInWorld2(body.ptr))
                 {
                     BulletSimAPI.AddObjectToWorld2(PhysicsScene.World.ptr, body.ptr);
-                    DetailLog("{0},BSShapeCollection.ReferenceBody,addedToWorld,ref={1}", body.ID, body);
+                    if (DDetail) DetailLog("{0},BSShapeCollection.ReferenceBody,addedToWorld,ref={1}", body.ID, body);
                 }
             });
         }
@@ -142,14 +154,14 @@ public sealed class BSShapeCollection : IDisposable
     // Called when releasing use of a BSBody. BSShape is handled separately.
     public void DereferenceBody(BulletBody body, bool inTaintTime, BodyDestructionCallback bodyCallback )
     {
-        if (body.ptr == IntPtr.Zero)
+        if (!body.HasPhysicalBody)
             return;
 
         lock (m_collectionActivityLock)
         {
             PhysicsScene.TaintedObject(inTaintTime, "BSShapeCollection.DereferenceBody", delegate()
             {
-                DetailLog("{0},BSShapeCollection.DereferenceBody,DestroyingBody,body={1},inTaintTime={2}",
+                if (DDetail) DetailLog("{0},BSShapeCollection.DereferenceBody,DestroyingBody,body={1},inTaintTime={2}",
                                             body.ID, body, inTaintTime);
                 // If the caller needs to know the old body is going away, pass the event up.
                 if (bodyCallback != null) bodyCallback(body);
@@ -157,7 +169,7 @@ public sealed class BSShapeCollection : IDisposable
                 if (BulletSimAPI.IsInWorld2(body.ptr))
                 {
                     BulletSimAPI.RemoveObjectFromWorld2(PhysicsScene.World.ptr, body.ptr);
-                    DetailLog("{0},BSShapeCollection.DereferenceBody,removingFromWorld. Body={1}", body.ID, body);
+                    if (DDetail) DetailLog("{0},BSShapeCollection.DereferenceBody,removingFromWorld. Body={1}", body.ID, body);
                 }
 
                 // Zero any reference to the shape so it is not freed when the body is deleted.
@@ -184,7 +196,7 @@ public sealed class BSShapeCollection : IDisposable
                 {
                     // There is an existing instance of this mesh.
                     meshDesc.referenceCount++;
-                    DetailLog("{0},BSShapeCollection.ReferenceShape,existingMesh,key={1},cnt={2}",
+                    if (DDetail) DetailLog("{0},BSShapeCollection.ReferenceShape,existingMesh,key={1},cnt={2}",
                                 BSScene.DetailLogZero, shape.shapeKey.ToString("X"), meshDesc.referenceCount);
                 }
                 else
@@ -194,7 +206,7 @@ public sealed class BSShapeCollection : IDisposable
                     meshDesc.shapeKey = shape.shapeKey;
                     // We keep a reference to the underlying IMesh data so a hull can be built
                     meshDesc.referenceCount = 1;
-                    DetailLog("{0},BSShapeCollection.ReferenceShape,newMesh,key={1},cnt={2}",
+                    if (DDetail) DetailLog("{0},BSShapeCollection.ReferenceShape,newMesh,key={1},cnt={2}",
                                 BSScene.DetailLogZero, shape.shapeKey.ToString("X"), meshDesc.referenceCount);
                     ret = true;
                 }
@@ -207,7 +219,7 @@ public sealed class BSShapeCollection : IDisposable
                 {
                     // There is an existing instance of this hull.
                     hullDesc.referenceCount++;
-                    DetailLog("{0},BSShapeCollection.ReferenceShape,existingHull,key={1},cnt={2}",
+                    if (DDetail) DetailLog("{0},BSShapeCollection.ReferenceShape,existingHull,key={1},cnt={2}",
                                 BSScene.DetailLogZero, shape.shapeKey.ToString("X"), hullDesc.referenceCount);
                 }
                 else
@@ -216,7 +228,7 @@ public sealed class BSShapeCollection : IDisposable
                     hullDesc.ptr = shape.ptr;
                     hullDesc.shapeKey = shape.shapeKey;
                     hullDesc.referenceCount = 1;
-                    DetailLog("{0},BSShapeCollection.ReferenceShape,newHull,key={1},cnt={2}",
+                    if (DDetail) DetailLog("{0},BSShapeCollection.ReferenceShape,newHull,key={1},cnt={2}",
                                 BSScene.DetailLogZero, shape.shapeKey.ToString("X"), hullDesc.referenceCount);
                     ret = true;
 
@@ -236,17 +248,17 @@ public sealed class BSShapeCollection : IDisposable
     // Release the usage of a shape.
     public void DereferenceShape(BulletShape shape, bool inTaintTime, ShapeDestructionCallback shapeCallback)
     {
-        if (shape.ptr == IntPtr.Zero)
+        if (!shape.HasPhysicalShape)
             return;
 
         PhysicsScene.TaintedObject(inTaintTime, "BSShapeCollection.DereferenceShape", delegate()
         {
-            if (shape.ptr != IntPtr.Zero)
+            if (shape.HasPhysicalShape)
             {
                 if (shape.isNativeShape)
                 {
                     // Native shapes are not tracked and are released immediately
-                    DetailLog("{0},BSShapeCollection.DereferenceShape,deleteNativeShape,ptr={1},taintTime={2}",
+                    if (DDetail) DetailLog("{0},BSShapeCollection.DereferenceShape,deleteNativeShape,ptr={1},taintTime={2}",
                                     BSScene.DetailLogZero, shape.ptr.ToString("X"), inTaintTime);
                     if (shapeCallback != null) shapeCallback(shape);
                     BulletSimAPI.DeleteCollisionShape2(PhysicsScene.World.ptr, shape.ptr);
@@ -286,7 +298,7 @@ public sealed class BSShapeCollection : IDisposable
             if (shapeCallback != null) shapeCallback(shape);
             meshDesc.lastReferenced = System.DateTime.Now;
             Meshes[shape.shapeKey] = meshDesc;
-            DetailLog("{0},BSShapeCollection.DereferenceMesh,shape={1},refCnt={2}",
+            if (DDetail) DetailLog("{0},BSShapeCollection.DereferenceMesh,shape={1},refCnt={2}",
                                 BSScene.DetailLogZero, shape, meshDesc.referenceCount);
 
         }
@@ -307,7 +319,7 @@ public sealed class BSShapeCollection : IDisposable
 
             hullDesc.lastReferenced = System.DateTime.Now;
             Hulls[shape.shapeKey] = hullDesc;
-            DetailLog("{0},BSShapeCollection.DereferenceHull,shape={1},refCnt={2}",
+            if (DDetail) DetailLog("{0},BSShapeCollection.DereferenceHull,shape={1},refCnt={2}",
                     BSScene.DetailLogZero, shape, hullDesc.referenceCount);
         }
     }
@@ -325,13 +337,13 @@ public sealed class BSShapeCollection : IDisposable
             // Failed the sanity check!!
             PhysicsScene.Logger.ErrorFormat("{0} Attempt to free a compound shape that is not compound!! type={1}, ptr={2}",
                                         LogHeader, shape.type, shape.ptr.ToString("X"));
-            DetailLog("{0},BSShapeCollection.DereferenceCompound,notACompoundShape,type={1},ptr={2}",
+            if (DDetail) DetailLog("{0},BSShapeCollection.DereferenceCompound,notACompoundShape,type={1},ptr={2}",
                                         BSScene.DetailLogZero, shape.type, shape.ptr.ToString("X"));
             return;
         }
 
         int numChildren = BulletSimAPI.GetNumberOfCompoundChildren2(shape.ptr);
-        DetailLog("{0},BSShapeCollection.DereferenceCompound,shape={1},children={2}", BSScene.DetailLogZero, shape, numChildren);
+        if (DDetail) DetailLog("{0},BSShapeCollection.DereferenceCompound,shape={1},children={2}", BSScene.DetailLogZero, shape, numChildren);
 
         for (int ii = numChildren - 1; ii >= 0; ii--)
         {
@@ -379,7 +391,7 @@ public sealed class BSShapeCollection : IDisposable
             }
         }
 
-        DetailLog("{0},BSShapeCollection.DereferenceAnonCollisionShape,shape={1}", BSScene.DetailLogZero, shapeInfo);
+        if (DDetail) DetailLog("{0},BSShapeCollection.DereferenceAnonCollisionShape,shape={1}", BSScene.DetailLogZero, shapeInfo);
 
         if (shapeInfo.type != BSPhysicsShapeType.SHAPE_UNKNOWN)
         {
@@ -408,19 +420,19 @@ public sealed class BSShapeCollection : IDisposable
         if (!haveShape && prim.PreferredPhysicalShape == BSPhysicsShapeType.SHAPE_CAPSULE)
         {
             // an avatar capsule is close to a native shape (it is not shared)
-            ret = GetReferenceToNativeShape(prim, BSPhysicsShapeType.SHAPE_CAPSULE,
+            GetReferenceToNativeShape(prim, BSPhysicsShapeType.SHAPE_CAPSULE,
                             FixedShapeKey.KEY_CAPSULE, shapeCallback);
-            DetailLog("{0},BSShapeCollection.CreateGeom,avatarCapsule,shape={1}", prim.LocalID, prim.PhysShape);
+            if (DDetail) DetailLog("{0},BSShapeCollection.CreateGeom,avatarCapsule,shape={1}", prim.LocalID, prim.PhysShape);
             ret = true;
             haveShape = true;
         }
 
         // Compound shapes are handled special as they are rebuilt from scratch.
-        // This isn't too great a hardship since most of the child shapes will already been created.
+        // This isn't too great a hardship since most of the child shapes will have already been created.
         if (!haveShape && prim.PreferredPhysicalShape == BSPhysicsShapeType.SHAPE_COMPOUND)
         {
             ret = GetReferenceToCompoundShape(prim, shapeCallback);
-            DetailLog("{0},BSShapeCollection.CreateGeom,compoundShape,shape={1}", prim.LocalID, prim.PhysShape);
+            if (DDetail) DetailLog("{0},BSShapeCollection.CreateGeom,compoundShape,shape={1}", prim.LocalID, prim.PhysShape);
             haveShape = true;
         }
 
@@ -433,7 +445,7 @@ public sealed class BSShapeCollection : IDisposable
     }
 
     // Create a mesh/hull shape or a native shape if 'nativeShapePossible' is 'true'.
-    private bool CreateGeomNonSpecial(bool forceRebuild, BSPhysObject prim, ShapeDestructionCallback shapeCallback)
+    public bool CreateGeomNonSpecial(bool forceRebuild, BSPhysObject prim, ShapeDestructionCallback shapeCallback)
     {
         bool ret = false;
         bool haveShape = false;
@@ -453,19 +465,27 @@ public sealed class BSShapeCollection : IDisposable
                         && pbs.PathScaleX == 100 && pbs.PathScaleY == 100
                         && pbs.PathShearX == 0 && pbs.PathShearY == 0) ) )
         {
+            // Get the scale of any existing shape so we can see if the new shape is same native type and same size.
+            OMV.Vector3 scaleOfExistingShape = OMV.Vector3.Zero;
+            if (prim.PhysShape.HasPhysicalShape)
+                scaleOfExistingShape = BulletSimAPI.GetLocalScaling2(prim.PhysShape.ptr);
+
+            if (DDetail) DetailLog("{0},BSShapeCollection.CreateGeom,maybeNative,force={1},primScale={2},primSize={3},primShape={4}",
+                        prim.LocalID, forceRebuild, prim.Scale, prim.Size, prim.PhysShape.type);
+
             // It doesn't look like Bullet scales spheres so make sure the scales are all equal
             if ((pbs.ProfileShape == ProfileShape.HalfCircle && pbs.PathCurve == (byte)Extrusion.Curve1)
                                 && pbs.Scale.X == pbs.Scale.Y && pbs.Scale.Y == pbs.Scale.Z)
             {
                 haveShape = true;
                 if (forceRebuild
-                        || prim.Scale != prim.Size
+                        || prim.Scale != scaleOfExistingShape
                         || prim.PhysShape.type != BSPhysicsShapeType.SHAPE_SPHERE
                         )
                 {
                     ret = GetReferenceToNativeShape(prim, BSPhysicsShapeType.SHAPE_SPHERE,
                                             FixedShapeKey.KEY_SPHERE, shapeCallback);
-                    DetailLog("{0},BSShapeCollection.CreateGeom,sphere,force={1},shape={2}",
+                    if (DDetail) DetailLog("{0},BSShapeCollection.CreateGeom,sphere,force={1},shape={2}",
                                         prim.LocalID, forceRebuild, prim.PhysShape);
                 }
             }
@@ -473,13 +493,13 @@ public sealed class BSShapeCollection : IDisposable
             {
                 haveShape = true;
                 if (forceRebuild
-                        || prim.Scale != prim.Size
+                        || prim.Scale != scaleOfExistingShape
                         || prim.PhysShape.type != BSPhysicsShapeType.SHAPE_BOX
                         )
                 {
                     ret = GetReferenceToNativeShape( prim, BSPhysicsShapeType.SHAPE_BOX,
                                             FixedShapeKey.KEY_BOX, shapeCallback);
-                    DetailLog("{0},BSShapeCollection.CreateGeom,box,force={1},shape={2}",
+                    if (DDetail) DetailLog("{0},BSShapeCollection.CreateGeom,box,force={1},shape={2}",
                                         prim.LocalID, forceRebuild, prim.PhysShape);
                 }
             }
@@ -504,13 +524,13 @@ public sealed class BSShapeCollection : IDisposable
         {
             // Update prim.BSShape to reference a hull of this shape.
             ret = GetReferenceToHull(prim,shapeCallback);
-            DetailLog("{0},BSShapeCollection.CreateGeom,hull,shape={1},key={2}",
+            if (DDetail) DetailLog("{0},BSShapeCollection.CreateGeom,hull,shape={1},key={2}",
                                     prim.LocalID, prim.PhysShape, prim.PhysShape.shapeKey.ToString("X"));
         }
         else
         {
             ret = GetReferenceToMesh(prim, shapeCallback);
-            DetailLog("{0},BSShapeCollection.CreateGeom,mesh,shape={1},key={2}",
+            if (DDetail) DetailLog("{0},BSShapeCollection.CreateGeom,mesh,shape={1},key={2}",
                                     prim.LocalID, prim.PhysShape, prim.PhysShape.shapeKey.ToString("X"));
         }
         return ret;
@@ -528,9 +548,10 @@ public sealed class BSShapeCollection : IDisposable
         BulletShape newShape = BuildPhysicalNativeShape(prim, shapeType, shapeKey);
 
         // Don't need to do a 'ReferenceShape()' here because native shapes are not shared.
-        DetailLog("{0},BSShapeCollection.AddNativeShapeToPrim,create,newshape={1},scale={2}",
+        if (DDetail) DetailLog("{0},BSShapeCollection.AddNativeShapeToPrim,create,newshape={1},scale={2}",
                                 prim.LocalID, newShape, prim.Scale);
 
+        // native shapes are scaled by Bullet
         prim.PhysShape = newShape;
         return true;
     }
@@ -554,16 +575,14 @@ public sealed class BSShapeCollection : IDisposable
             newShape = new BulletShape(
                         BulletSimAPI.BuildCapsuleShape2(PhysicsScene.World.ptr, 1f, 1f, prim.Scale)
                         , shapeType);
-            DetailLog("{0},BSShapeCollection.BuiletPhysicalNativeShape,capsule,scale={1}", prim.LocalID, prim.Scale);
+            if (DDetail) DetailLog("{0},BSShapeCollection.BuiletPhysicalNativeShape,capsule,scale={1}", prim.LocalID, prim.Scale);
         }
         else
         {
             // Native shapes are scaled in Bullet so set the scaling to the size
-            prim.Scale = prim.Size;
-            nativeShapeData.Scale = prim.Scale;
             newShape = new BulletShape(BulletSimAPI.BuildNativeShape2(PhysicsScene.World.ptr, nativeShapeData), shapeType);
         }
-        if (newShape.ptr == IntPtr.Zero)
+        if (!newShape.HasPhysicalShape)
         {
             PhysicsScene.Logger.ErrorFormat("{0} BuildPhysicalNativeShape failed. ID={1}, shape={2}",
                                     LogHeader, prim.LocalID, shapeType);
@@ -580,7 +599,7 @@ public sealed class BSShapeCollection : IDisposable
     // Called at taint-time!
     private bool GetReferenceToMesh(BSPhysObject prim, ShapeDestructionCallback shapeCallback)
     {
-        BulletShape newShape = new BulletShape(IntPtr.Zero);
+        BulletShape newShape = new BulletShape();
 
         float lod;
         System.UInt64 newMeshKey = ComputeShapeKey(prim.Size, prim.BaseShape, out lod);
@@ -589,7 +608,7 @@ public sealed class BSShapeCollection : IDisposable
         if (newMeshKey == prim.PhysShape.shapeKey && prim.PhysShape.type == BSPhysicsShapeType.SHAPE_MESH)
             return false;
 
-        DetailLog("{0},BSShapeCollection.GetReferenceToMesh,create,oldKey={1},newKey={2}",
+        if (DDetail) DetailLog("{0},BSShapeCollection.GetReferenceToMesh,create,oldKey={1},newKey={2}",
                                 prim.LocalID, prim.PhysShape.shapeKey.ToString("X"), newMeshKey.ToString("X"));
 
         // Since we're recreating new, get rid of the reference to the previous shape
@@ -601,8 +620,6 @@ public sealed class BSShapeCollection : IDisposable
 
         ReferenceShape(newShape);
 
-        // meshes are already scaled by the meshmerizer
-        prim.Scale = new OMV.Vector3(1f, 1f, 1f);
         prim.PhysShape = newShape;
 
         return true;        // 'true' means a new shape has been added to this prim
@@ -620,8 +637,7 @@ public sealed class BSShapeCollection : IDisposable
         }
         else
         {
-            // Pass false for physicalness as this creates some sort of bounding box which we don't need
-            meshData = PhysicsScene.mesher.CreateMesh(objName, pbs, size, lod, false);
+            meshData = PhysicsScene.mesher.CreateMesh(objName, pbs, size, lod, true, false, false, false);
 
             if (meshData != null)
             {
@@ -663,7 +679,7 @@ public sealed class BSShapeCollection : IDisposable
         if (newHullKey == prim.PhysShape.shapeKey && prim.PhysShape.type == BSPhysicsShapeType.SHAPE_HULL)
             return false;
 
-        DetailLog("{0},BSShapeCollection.GetReferenceToHull,create,oldKey={1},newKey={2}",
+        if (DDetail) DetailLog("{0},BSShapeCollection.GetReferenceToHull,create,oldKey={1},newKey={2}",
                         prim.LocalID, prim.PhysShape.shapeKey.ToString("X"), newHullKey.ToString("X"));
 
         // Remove usage of the previous shape.
@@ -674,8 +690,6 @@ public sealed class BSShapeCollection : IDisposable
 
         ReferenceShape(newShape);
 
-        // hulls are already scaled by the meshmerizer
-        prim.Scale = new OMV.Vector3(1f, 1f, 1f);
         prim.PhysShape = newShape;
         return true;        // 'true' means a new shape has been added to this prim
     }
@@ -694,8 +708,8 @@ public sealed class BSShapeCollection : IDisposable
         else
         {
             // Build a new hull in the physical world
-            // Pass false for physicalness as this creates some sort of bounding box which we don't need
-            IMesh meshData = PhysicsScene.mesher.CreateMesh(objName, pbs, size, lod, false);
+            // Pass true for physicalness as this creates some sort of bounding box which we don't need
+            IMesh meshData = PhysicsScene.mesher.CreateMesh(objName, pbs, size, lod, true, false, false, false);
             if (meshData != null)
             {
 
@@ -784,7 +798,7 @@ public sealed class BSShapeCollection : IDisposable
         BulletShape newShape = new BulletShape(hullPtr, BSPhysicsShapeType.SHAPE_HULL);
         newShape.shapeKey = newHullKey;
 
-        return newShape;        // 'true' means a new shape has been added to this prim
+        return newShape;
     }
 
     // Callback from convex hull creater with a newly created hull.
@@ -809,7 +823,7 @@ public sealed class BSShapeCollection : IDisposable
         // Create the shape for the root prim and add it to the compound shape. Cannot be a native shape.
         CreateGeomMeshOrHull(prim, shapeCallback);
         BulletSimAPI.AddChildShapeToCompoundShape2(cShape.ptr, prim.PhysShape.ptr, OMV.Vector3.Zero, OMV.Quaternion.Identity);
-        DetailLog("{0},BSShapeCollection.GetReferenceToCompoundShape,addRootPrim,compShape={1},rootShape={2}",
+        if (DDetail) DetailLog("{0},BSShapeCollection.GetReferenceToCompoundShape,addRootPrim,compShape={1},rootShape={2}",
                                     prim.LocalID, cShape, prim.PhysShape);
 
         prim.PhysShape = cShape;
@@ -851,7 +865,7 @@ public sealed class BSShapeCollection : IDisposable
     private BulletShape VerifyMeshCreated(BulletShape newShape, BSPhysObject prim)
     {
         // If the shape was successfully created, nothing more to do
-        if (newShape.ptr != IntPtr.Zero)
+        if (newShape.HasPhysicalShape)
             return newShape;
 
         // If this mesh has an underlying asset and we have not failed getting it before, fetch the asset
@@ -910,7 +924,7 @@ public sealed class BSShapeCollection : IDisposable
         bool ret = false;
 
         // the mesh, hull or native shape must have already been created in Bullet
-        bool mustRebuild = (prim.PhysBody.ptr == IntPtr.Zero);
+        bool mustRebuild = !prim.PhysBody.HasPhysicalBody;
 
         // If there is an existing body, verify it's of an acceptable type.
         // If not a solid object, body is a GhostObject. Otherwise a RigidBody.
@@ -936,13 +950,13 @@ public sealed class BSShapeCollection : IDisposable
             {
                 bodyPtr = BulletSimAPI.CreateBodyFromShape2(sim.ptr, shape.ptr,
                                         prim.LocalID, prim.RawPosition, prim.RawOrientation);
-                DetailLog("{0},BSShapeCollection.CreateBody,mesh,ptr={1}", prim.LocalID, bodyPtr.ToString("X"));
+                if (DDetail) DetailLog("{0},BSShapeCollection.CreateBody,mesh,ptr={1}", prim.LocalID, bodyPtr.ToString("X"));
             }
             else
             {
                 bodyPtr = BulletSimAPI.CreateGhostFromShape2(sim.ptr, shape.ptr,
                                         prim.LocalID, prim.RawPosition, prim.RawOrientation);
-                DetailLog("{0},BSShapeCollection.CreateBody,ghost,ptr={1}", prim.LocalID, bodyPtr.ToString("X"));
+                if (DDetail) DetailLog("{0},BSShapeCollection.CreateBody,ghost,ptr={1}", prim.LocalID, bodyPtr.ToString("X"));
             }
             aBody = new BulletBody(prim.LocalID, bodyPtr);
 
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSTerrainHeightmap.cs b/OpenSim/Region/Physics/BulletSPlugin/BSTerrainHeightmap.cs
index 3ca756c..2b120d6 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSTerrainHeightmap.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSTerrainHeightmap.cs
@@ -93,7 +93,7 @@ public sealed class BSTerrainHeightmap : BSTerrainPhys
     {
         m_mapInfo.Ptr = BulletSimAPI.CreateHeightMapInfo2(PhysicsScene.World.ptr, m_mapInfo.ID,
                                 m_mapInfo.minCoords, m_mapInfo.maxCoords, 
-                                m_mapInfo.heightMap, BSTerrainManager.TERRAIN_COLLISION_MARGIN);
+                                m_mapInfo.heightMap, PhysicsScene.Params.terrainCollisionMargin);
 
         // Create the terrain shape from the mapInfo
         m_mapInfo.terrainShape = new BulletShape(BulletSimAPI.CreateTerrainShape2(m_mapInfo.Ptr),
@@ -121,9 +121,8 @@ public sealed class BSTerrainHeightmap : BSTerrainPhys
         // redo its bounding box now that it is in the world
         BulletSimAPI.UpdateSingleAabb2(PhysicsScene.World.ptr, m_mapInfo.terrainBody.ptr);
 
-        BulletSimAPI.SetCollisionFilterMask2(m_mapInfo.terrainBody.ptr,
-                            (uint)CollisionFilterGroups.TerrainFilter,
-                            (uint)CollisionFilterGroups.TerrainMask);
+        m_mapInfo.terrainBody.collisionType = CollisionType.Terrain;
+        m_mapInfo.terrainBody.ApplyCollisionMask();
 
         // Make it so the terrain will not move or be considered for movement.
         BulletSimAPI.ForceActivationState2(m_mapInfo.terrainBody.ptr, ActivationState.DISABLE_SIMULATION);
@@ -136,7 +135,7 @@ public sealed class BSTerrainHeightmap : BSTerrainPhys
     {
         if (m_mapInfo != null)
         {
-            if (m_mapInfo.terrainBody.ptr != IntPtr.Zero)
+            if (m_mapInfo.terrainBody.HasPhysicalBody)
             {
                 BulletSimAPI.RemoveObjectFromWorld2(PhysicsScene.World.ptr, m_mapInfo.terrainBody.ptr);
                 // Frees both the body and the shape.
@@ -148,7 +147,7 @@ public sealed class BSTerrainHeightmap : BSTerrainPhys
     }
 
     // The passed position is relative to the base of the region.
-    public override float GetHeightAtXYZ(Vector3 pos)
+    public override float GetTerrainHeightAtXYZ(Vector3 pos)
     {
         float ret = BSTerrainManager.HEIGHT_GETHEIGHT_RET;
 
@@ -166,5 +165,11 @@ public sealed class BSTerrainHeightmap : BSTerrainPhys
         }
         return ret;
     }
+
+    // The passed position is relative to the base of the region.
+    public override float GetWaterLevelAtXYZ(Vector3 pos)
+    {
+        return PhysicsScene.SimpleWaterLevel;
+    }
 }
 }
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSTerrainManager.cs b/OpenSim/Region/Physics/BulletSPlugin/BSTerrainManager.cs
index 23fcfd3..3428b9c 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSTerrainManager.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSTerrainManager.cs
@@ -62,11 +62,12 @@ public abstract class BSTerrainPhys : IDisposable
         ID = id;
     }
     public abstract void Dispose();
-    public abstract float GetHeightAtXYZ(Vector3 pos);
+    public abstract float GetTerrainHeightAtXYZ(Vector3 pos);
+    public abstract float GetWaterLevelAtXYZ(Vector3 pos);
 }
 
 // ==========================================================================================
-public sealed class BSTerrainManager
+public sealed class BSTerrainManager : IDisposable
 {
     static string LogHeader = "[BULLETSIM TERRAIN MANAGER]";
 
@@ -75,13 +76,12 @@ public sealed class BSTerrainManager
     public const float HEIGHT_INITIALIZATION = 24.987f;
     public const float HEIGHT_INITIAL_LASTHEIGHT = 24.876f;
     public const float HEIGHT_GETHEIGHT_RET = 24.765f;
+    public const float WATER_HEIGHT_GETHEIGHT_RET = 19.998f;
 
     // If the min and max height are equal, we reduce the min by this
     //    amount to make sure that a bounding box is built for the terrain.
     public const float HEIGHT_EQUAL_FUDGE = 0.2f;
 
-    public const float TERRAIN_COLLISION_MARGIN = 0.0f;
-
     // Until the whole simulator is changed to pass us the region size, we rely on constants.
     public Vector3 DefaultRegionSize = new Vector3(Constants.RegionSize, Constants.RegionSize, Constants.RegionHeight);
 
@@ -122,6 +122,11 @@ public sealed class BSTerrainManager
         MegaRegionParentPhysicsScene = null;
     }
 
+    public void Dispose()
+    {
+        ReleaseGroundPlaneAndTerrain();
+    }
+
     // Create the initial instance of terrain and the underlying ground plane.
     // This is called from the initialization routine so we presume it is
     //    safe to call Bullet in real time. We hope no one is moving prims around yet.
@@ -129,7 +134,8 @@ public sealed class BSTerrainManager
     {
         // The ground plane is here to catch things that are trying to drop to negative infinity
         BulletShape groundPlaneShape = new BulletShape(
-                    BulletSimAPI.CreateGroundPlaneShape2(BSScene.GROUNDPLANE_ID, 1f, TERRAIN_COLLISION_MARGIN),
+                    BulletSimAPI.CreateGroundPlaneShape2(BSScene.GROUNDPLANE_ID, 1f, 
+                                    PhysicsScene.Params.terrainCollisionMargin),
                     BSPhysicsShapeType.SHAPE_GROUNDPLANE);
         m_groundPlane = new BulletBody(BSScene.GROUNDPLANE_ID,
                         BulletSimAPI.CreateBodyWithDefaultMotionState2(groundPlaneShape.ptr, BSScene.GROUNDPLANE_ID,
@@ -139,8 +145,8 @@ public sealed class BSTerrainManager
         // Ground plane does not move
         BulletSimAPI.ForceActivationState2(m_groundPlane.ptr, ActivationState.DISABLE_SIMULATION);
         // Everything collides with the ground plane.
-        BulletSimAPI.SetCollisionFilterMask2(m_groundPlane.ptr,
-                        (uint)CollisionFilterGroups.GroundPlaneFilter, (uint)CollisionFilterGroups.GroundPlaneMask);
+        m_groundPlane.collisionType = CollisionType.Groundplane;
+        m_groundPlane.ApplyCollisionMask();
 
         // Build an initial terrain and put it in the world. This quickly gets replaced by the real region terrain.
         BSTerrainPhys initialTerrain = new BSTerrainHeightmap(PhysicsScene, Vector3.Zero, BSScene.TERRAIN_ID, DefaultRegionSize);
@@ -150,13 +156,13 @@ public sealed class BSTerrainManager
     // Release all the terrain structures we might have allocated
     public void ReleaseGroundPlaneAndTerrain()
     {
-        if (m_groundPlane.ptr != IntPtr.Zero)
+        if (m_groundPlane.HasPhysicalBody)
         {
             if (BulletSimAPI.RemoveObjectFromWorld2(PhysicsScene.World.ptr, m_groundPlane.ptr))
             {
                 BulletSimAPI.DestroyObject2(PhysicsScene.World.ptr, m_groundPlane.ptr);
             }
-            m_groundPlane.ptr = IntPtr.Zero;
+            m_groundPlane.Clear();
         }
 
         ReleaseTerrain();
@@ -165,17 +171,22 @@ public sealed class BSTerrainManager
     // Release all the terrain we have allocated
     public void ReleaseTerrain()
     {
-        foreach (KeyValuePair<Vector3, BSTerrainPhys> kvp in m_terrains)
+        lock (m_terrains)
         {
-            kvp.Value.Dispose();
+            foreach (KeyValuePair<Vector3, BSTerrainPhys> kvp in m_terrains)
+            {
+                kvp.Value.Dispose();
+            }
+            m_terrains.Clear();
         }
-        m_terrains.Clear();
     }
 
     // The simulator wants to set a new heightmap for the terrain.
     public void SetTerrain(float[] heightMap) {
         float[] localHeightMap = heightMap;
-        PhysicsScene.TaintedObject("TerrainManager.SetTerrain", delegate()
+        // If there are multiple requests for changes to the same terrain between ticks,
+        //      only do that last one.
+        PhysicsScene.PostTaintObject("TerrainManager.SetTerrain-"+ m_worldOffset.ToString(), 0, delegate()
         {
             if (m_worldOffset != Vector3.Zero && MegaRegionParentPhysicsScene != null)
             {
@@ -211,6 +222,7 @@ public sealed class BSTerrainManager
     //     terrain shape is created and added to the body.
     //     This call is most often used to update the heightMap and parameters of the terrain.
     // (The above does suggest that some simplification/refactoring is in order.)
+    // Called during taint-time.
     private void UpdateTerrain(uint id, float[] heightMap, 
                             Vector3 minCoords, Vector3 maxCoords, bool inTaintTime)
     {
@@ -220,7 +232,7 @@ public sealed class BSTerrainManager
         // Find high and low points of passed heightmap.
         // The min and max passed in is usually the area objects can be in (maximum
         //     object height, for instance). The terrain wants the bounding box for the
-        //     terrain so we replace passed min and max Z with the actual terrain min/max Z.
+        //     terrain so replace passed min and max Z with the actual terrain min/max Z.
         float minZ = float.MaxValue;
         float maxZ = float.MinValue;
         foreach (float height in heightMap)
@@ -238,15 +250,15 @@ public sealed class BSTerrainManager
 
         Vector3 terrainRegionBase = new Vector3(minCoords.X, minCoords.Y, 0f);
 
-        BSTerrainPhys terrainPhys;
-        if (m_terrains.TryGetValue(terrainRegionBase, out terrainPhys))
+        lock (m_terrains)
         {
-            // There is already a terrain in this spot. Free the old and build the new.
-            DetailLog("{0},UpdateTerrain:UpdateExisting,call,id={1},base={2},minC={3},maxC={4}",
-                            BSScene.DetailLogZero, id, terrainRegionBase, minCoords, minCoords);
-
-            PhysicsScene.TaintedObject(inTaintTime, "BSScene.UpdateTerrain:UpdateExisting", delegate()
+            BSTerrainPhys terrainPhys;
+            if (m_terrains.TryGetValue(terrainRegionBase, out terrainPhys))
             {
+                // There is already a terrain in this spot. Free the old and build the new.
+                DetailLog("{0},UpdateTerrain:UpdateExisting,call,id={1},base={2},minC={3},maxC={4}",
+                                BSScene.DetailLogZero, id, terrainRegionBase, minCoords, minCoords);
+
                 // Remove old terrain from the collection
                 m_terrains.Remove(terrainRegionBase);
                 // Release any physical memory it may be using.
@@ -271,35 +283,24 @@ public sealed class BSTerrainManager
                     // I hate doing this, but just bail
                     return;
                 }
-            });
-        }
-        else
-        {
-            // We don't know about this terrain so either we are creating a new terrain or
-            //    our mega-prim child is giving us a new terrain to add to the phys world
-
-            // if this is a child terrain, calculate a unique terrain id
-            uint newTerrainID = id;
-            if (newTerrainID >= BSScene.CHILDTERRAIN_ID)
-                newTerrainID = ++m_terrainCount;
-
-            float[] heightMapX = heightMap;
-            Vector3 minCoordsX = minCoords;
-            Vector3 maxCoordsX = maxCoords;
+            }
+            else
+            {
+                // We don't know about this terrain so either we are creating a new terrain or
+                //    our mega-prim child is giving us a new terrain to add to the phys world
 
-            DetailLog("{0},UpdateTerrain:NewTerrain,call,id={1}, minC={2}, maxC={3}",
-                            BSScene.DetailLogZero, newTerrainID, minCoords, minCoords);
+                // if this is a child terrain, calculate a unique terrain id
+                uint newTerrainID = id;
+                if (newTerrainID >= BSScene.CHILDTERRAIN_ID)
+                    newTerrainID = ++m_terrainCount;
 
-            // Code that must happen at taint-time
-            PhysicsScene.TaintedObject(inTaintTime, "BSScene.UpdateTerrain:NewTerrain", delegate()
-            {
-                DetailLog("{0},UpdateTerrain:NewTerrain,taint,baseX={1},baseY={2}", 
-                                            BSScene.DetailLogZero, minCoordsX.X, minCoordsX.Y);
+                DetailLog("{0},UpdateTerrain:NewTerrain,taint,newID={1},minCoord={2},maxCoord={3}",
+                                            BSScene.DetailLogZero, newTerrainID, minCoords, minCoords);
                 BSTerrainPhys newTerrainPhys = BuildPhysicalTerrain(terrainRegionBase, id, heightMap, minCoords, maxCoords);
                 m_terrains.Add(terrainRegionBase, newTerrainPhys);
 
                 m_terrainModified = true;
-            });
+            }
         }
     }
 
@@ -331,6 +332,13 @@ public sealed class BSTerrainManager
         return newTerrainPhys;
     }
 
+    // Return 'true' of this position is somewhere in known physical terrain space
+    public bool IsWithinKnownTerrain(Vector3 pos)
+    {
+        Vector3 terrainBaseXYZ;
+        BSTerrainPhys physTerrain;
+        return GetTerrainPhysicalAtXYZ(pos, out physTerrain, out terrainBaseXYZ);
+    }
 
     // Given an X and Y, find the height of the terrain.
     // Since we could be handling multiple terrains for a mega-region,
@@ -341,40 +349,74 @@ public sealed class BSTerrainManager
     private float lastHeightTX = 999999f;
     private float lastHeightTY = 999999f;
     private float lastHeight = HEIGHT_INITIAL_LASTHEIGHT;
-    public float GetTerrainHeightAtXYZ(Vector3 loc)
+    public float GetTerrainHeightAtXYZ(Vector3 pos)
     {
-        float tX = loc.X;
-        float tY = loc.Y;
+        float tX = pos.X;
+        float tY = pos.Y;
         // You'd be surprized at the number of times this routine is called
         //    with the same parameters as last time.
-        if (!m_terrainModified && lastHeightTX == tX && lastHeightTY == tY)
+        if (!m_terrainModified && (lastHeightTX == tX) && (lastHeightTY == tY))
             return lastHeight;
+        m_terrainModified = false;
 
         lastHeightTX = tX;
         lastHeightTY = tY;
         float ret = HEIGHT_GETHEIGHT_RET;
 
-        int offsetX = ((int)(tX / (int)DefaultRegionSize.X)) * (int)DefaultRegionSize.X;
-        int offsetY = ((int)(tY / (int)DefaultRegionSize.Y)) * (int)DefaultRegionSize.Y;
-        Vector3 terrainBaseXYZ = new Vector3(offsetX, offsetY, 0f);
-
+        Vector3 terrainBaseXYZ;
         BSTerrainPhys physTerrain;
-        if (m_terrains.TryGetValue(terrainBaseXYZ, out physTerrain))
+        if (GetTerrainPhysicalAtXYZ(pos, out physTerrain, out terrainBaseXYZ))
         {
-            ret = physTerrain.GetHeightAtXYZ(loc - terrainBaseXYZ);
-            DetailLog("{0},BSTerrainManager.GetTerrainHeightAtXYZ,loc={1},base={2},height={3}",
-                                             BSScene.DetailLogZero, loc, terrainBaseXYZ, ret);
+            ret = physTerrain.GetTerrainHeightAtXYZ(pos - terrainBaseXYZ);
         }
         else
         {
             PhysicsScene.Logger.ErrorFormat("{0} GetTerrainHeightAtXY: terrain not found: region={1}, x={2}, y={3}",
                     LogHeader, PhysicsScene.RegionName, tX, tY);
+            DetailLog("{0},BSTerrainManager.GetTerrainHeightAtXYZ,terrainNotFound,pos={1},base={2}",
+                                BSScene.DetailLogZero, pos, terrainBaseXYZ);
         }
-        m_terrainModified = false;
+
         lastHeight = ret;
         return ret;
     }
 
+    public float GetWaterLevelAtXYZ(Vector3 pos)
+    {
+        float ret = WATER_HEIGHT_GETHEIGHT_RET;
+
+        Vector3 terrainBaseXYZ;
+        BSTerrainPhys physTerrain;
+        if (GetTerrainPhysicalAtXYZ(pos, out physTerrain, out terrainBaseXYZ))
+        {
+            ret = physTerrain.GetWaterLevelAtXYZ(pos);
+        }
+        else
+        {
+            PhysicsScene.Logger.ErrorFormat("{0} GetWaterHeightAtXY: terrain not found: pos={1}, terrainBase={2}, height={3}",
+                    LogHeader, PhysicsScene.RegionName, pos, terrainBaseXYZ, ret);
+        }
+        return ret;
+    }
+
+    // Given an address, return 'true' of there is a description of that terrain and output
+    //    the descriptor class and the 'base' fo the addresses therein.
+    private bool GetTerrainPhysicalAtXYZ(Vector3 pos, out BSTerrainPhys outPhysTerrain, out Vector3 outTerrainBase)
+    {
+        int offsetX = ((int)(pos.X / (int)DefaultRegionSize.X)) * (int)DefaultRegionSize.X;
+        int offsetY = ((int)(pos.Y / (int)DefaultRegionSize.Y)) * (int)DefaultRegionSize.Y;
+        Vector3 terrainBaseXYZ = new Vector3(offsetX, offsetY, 0f);
+
+        BSTerrainPhys physTerrain = null;
+        lock (m_terrains)
+        {
+            m_terrains.TryGetValue(terrainBaseXYZ, out physTerrain);
+        }
+        outTerrainBase = terrainBaseXYZ;
+        outPhysTerrain = physTerrain;
+        return (physTerrain != null);
+    }
+
     // Although no one seems to check this, I do support combining.
     public bool SupportsCombining()
     {
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSTerrainMesh.cs b/OpenSim/Region/Physics/BulletSPlugin/BSTerrainMesh.cs
index dca7150..6dc0d92 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSTerrainMesh.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSTerrainMesh.cs
@@ -88,11 +88,13 @@ public sealed class BSTerrainMesh : BSTerrainPhys
             // Something is very messed up and a crash is in our future.
             return;
         }
+        PhysicsScene.DetailLog("{0},BSTerrainMesh.create,meshed,indices={1},indSz={2},vertices={3},vertSz={4}", 
+                                ID, indicesCount, indices.Length, verticesCount, vertices.Length);
 
         m_terrainShape = new BulletShape(BulletSimAPI.CreateMeshShape2(PhysicsScene.World.ptr,
-                                        indicesCount, indices, verticesCount, vertices),
+                                                    indicesCount, indices, verticesCount, vertices),
                                         BSPhysicsShapeType.SHAPE_MESH);
-        if (m_terrainShape.ptr == IntPtr.Zero)
+        if (!m_terrainShape.HasPhysicalShape)
         {
             // DISASTER!!
             PhysicsScene.DetailLog("{0},BSTerrainMesh.create,failedCreationOfShape", ID);
@@ -105,7 +107,7 @@ public sealed class BSTerrainMesh : BSTerrainPhys
         Quaternion rot = Quaternion.Identity;
 
         m_terrainBody = new BulletBody(id, BulletSimAPI.CreateBodyWithDefaultMotionState2( m_terrainShape.ptr, ID, pos, rot));
-        if (m_terrainBody.ptr == IntPtr.Zero)
+        if (!m_terrainBody.HasPhysicalBody)
         {
             // DISASTER!!
             physicsScene.Logger.ErrorFormat("{0} Failed creation of terrain body! base={1}", LogHeader, TerrainBase);
@@ -122,15 +124,14 @@ public sealed class BSTerrainMesh : BSTerrainPhys
         // Static objects are not very massive.
         BulletSimAPI.SetMassProps2(m_terrainBody.ptr, 0f, Vector3.Zero);
 
-        // Return the new terrain to the world of physical objects
+        // Put the new terrain to the world of physical objects
         BulletSimAPI.AddObjectToWorld2(PhysicsScene.World.ptr, m_terrainBody.ptr);
 
-        // redo its bounding box now that it is in the world
+        // Redo its bounding box now that it is in the world
         BulletSimAPI.UpdateSingleAabb2(PhysicsScene.World.ptr, m_terrainBody.ptr);
 
-        BulletSimAPI.SetCollisionFilterMask2(m_terrainBody.ptr,
-                            (uint)CollisionFilterGroups.TerrainFilter,
-                            (uint)CollisionFilterGroups.TerrainMask);
+        m_terrainBody.collisionType = CollisionType.Terrain;
+        m_terrainBody.ApplyCollisionMask();
 
         // Make it so the terrain will not move or be considered for movement.
         BulletSimAPI.ForceActivationState2(m_terrainBody.ptr, ActivationState.DISABLE_SIMULATION);
@@ -138,7 +139,7 @@ public sealed class BSTerrainMesh : BSTerrainPhys
 
     public override void Dispose()
     {
-        if (m_terrainBody.ptr != IntPtr.Zero)
+        if (m_terrainBody.HasPhysicalBody)
         {
             BulletSimAPI.RemoveObjectFromWorld2(PhysicsScene.World.ptr, m_terrainBody.ptr);
             // Frees both the body and the shape.
@@ -146,7 +147,7 @@ public sealed class BSTerrainMesh : BSTerrainPhys
         }
     }
 
-    public override float GetHeightAtXYZ(Vector3 pos)
+    public override float GetTerrainHeightAtXYZ(Vector3 pos)
     {
         // For the moment use the saved heightmap to get the terrain height.
         // TODO: raycast downward to find the true terrain below the position.
@@ -167,6 +168,12 @@ public sealed class BSTerrainMesh : BSTerrainPhys
         return ret;
     }
 
+    // The passed position is relative to the base of the region.
+    public override float GetWaterLevelAtXYZ(Vector3 pos)
+    {
+        return PhysicsScene.SimpleWaterLevel;
+    }
+
     // Convert the passed heightmap to mesh information suitable for CreateMeshShape2().
     // Return 'true' if successfully created.
     public static bool ConvertHeightmapToMesh(
@@ -188,6 +195,11 @@ public sealed class BSTerrainMesh : BSTerrainPhys
         // Simple mesh creation which assumes magnification == 1.
         // TODO: do a more general solution that scales, adds new vertices and smoothes the result.
 
+        // Create an array of vertices that is sizeX+1 by sizeY+1 (note the loop
+        //    from zero to <= sizeX). The triangle indices are then generated as two triangles
+        //    per heightmap point. There are sizeX by sizeY of these squares. The extra row and
+        //    column of vertices are used to complete the triangles of the last row and column
+        //    of the heightmap.
         try
         {
             // One vertice per heightmap value plus the vertices off the top and bottom edge.
@@ -200,16 +212,18 @@ public sealed class BSTerrainMesh : BSTerrainPhys
             float magY = (float)sizeY / extentY;
             physicsScene.DetailLog("{0},BSTerrainMesh.ConvertHeightMapToMesh,totVert={1},totInd={2},extentBase={3},magX={4},magY={5}",
                                     BSScene.DetailLogZero, totalVertices, totalIndices, extentBase, magX, magY);
+            float minHeight = float.MaxValue;
             // Note that sizeX+1 vertices are created since there is land between this and the next region.
             for (int yy = 0; yy <= sizeY; yy++)
             {
-                for (int xx = 0; xx <= sizeX; xx++)     // Hint: the "<=" means we got through sizeX + 1 times
+                for (int xx = 0; xx <= sizeX; xx++)     // Hint: the "<=" means we go around sizeX + 1 times
                 {
                     int offset = yy * sizeX + xx;
-                    // Extend the height from the height from the last row or column
+                    // Extend the height with the height from the last row or column
                     if (yy == sizeY) offset -= sizeX;
                     if (xx == sizeX) offset -= 1;
                     float height = heightMap[offset];
+                    minHeight = Math.Min(minHeight, height);
                     vertices[verticesCount + 0] = (float)xx * magX + extentBase.X;
                     vertices[verticesCount + 1] = (float)yy * magY + extentBase.Y;
                     vertices[verticesCount + 2] = height + extentBase.Z;
@@ -217,14 +231,12 @@ public sealed class BSTerrainMesh : BSTerrainPhys
                 }
             }
             verticesCount = verticesCount / 3;
-            physicsScene.DetailLog("{0},BSTerrainMesh.ConvertHeightMapToMesh,completeVerts,verCount={1}", 
-                                            BSScene.DetailLogZero, verticesCount);
 
             for (int yy = 0; yy < sizeY; yy++)
             {
                 for (int xx = 0; xx < sizeX; xx++)
                 {
-                    int offset = yy * sizeX + xx;
+                    int offset = yy * (sizeX + 1) + xx;
                     // Each vertices is presumed to be the upper left corner of a box of two triangles
                     indices[indicesCount + 0] = offset;
                     indices[indicesCount + 1] = offset + 1;
@@ -235,8 +247,7 @@ public sealed class BSTerrainMesh : BSTerrainPhys
                     indicesCount += 6;
                 }
             }
-            physicsScene.DetailLog("{0},BSTerrainMesh.ConvertHeightMapToMesh,completeIndices,indCount={1}",   // DEEBUG DEBUG DEBUG
-                                                        LogHeader, indicesCount);                        // DEBUG
+
             ret = true;
         }
         catch (Exception e)
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BulletSimAPI.cs b/OpenSim/Region/Physics/BulletSPlugin/BulletSimAPI.cs
index e60a760..962b540 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BulletSimAPI.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BulletSimAPI.cs
@@ -25,6 +25,7 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 using System;
+using System.Collections.Generic;
 using System.Runtime.InteropServices;
 using System.Security;
 using System.Text;
@@ -32,93 +33,6 @@ using OpenMetaverse;
 
 namespace OpenSim.Region.Physics.BulletSPlugin {
 
-// Classes to allow some type checking for the API
-// These hold pointers to allocated objects in the unmanaged space.
-
-// The physics engine controller class created at initialization
-public struct BulletSim
-{
-    public BulletSim(uint worldId, BSScene bss, IntPtr xx)
-    {
-        ptr = xx;
-        worldID = worldId;
-        physicsScene = bss;
-    }
-    public IntPtr ptr;
-    public uint worldID;
-    // The scene is only in here so very low level routines have a handle to print debug/error messages
-    public BSScene physicsScene;
-}
-
-// An allocated Bullet btRigidBody
-public struct BulletBody
-{
-    public BulletBody(uint id, IntPtr xx)
-    {
-        ID = id;
-        ptr = xx;
-        collisionFilter = 0;
-        collisionMask = 0;
-    }
-    public IntPtr ptr;
-    public uint ID;
-    public CollisionFilterGroups collisionFilter;
-    public CollisionFilterGroups collisionMask;
-    public override string ToString()
-    {
-        StringBuilder buff = new StringBuilder();
-        buff.Append("<id=");
-        buff.Append(ID.ToString());
-        buff.Append(",p=");
-        buff.Append(ptr.ToString("X"));
-        if (collisionFilter != 0 || collisionMask != 0)
-        {
-            buff.Append(",f=");
-            buff.Append(collisionFilter.ToString("X"));
-            buff.Append(",m=");
-            buff.Append(collisionMask.ToString("X"));
-        }
-        buff.Append(">");
-        return buff.ToString();
-    }
-}
-
-public struct BulletShape
-{
-    public BulletShape(IntPtr xx)
-    {
-        ptr = xx;
-        type=BSPhysicsShapeType.SHAPE_UNKNOWN;
-        shapeKey = (System.UInt64)FixedShapeKey.KEY_NONE;
-        isNativeShape = false;
-    }
-    public BulletShape(IntPtr xx, BSPhysicsShapeType typ)
-    {
-        ptr = xx;
-        type = typ;
-        shapeKey = 0;
-        isNativeShape = false;
-    }
-    public IntPtr ptr;
-    public BSPhysicsShapeType type;
-    public System.UInt64 shapeKey;
-    public bool isNativeShape;
-    public override string ToString()
-    {
-        StringBuilder buff = new StringBuilder();
-        buff.Append("<p=");
-        buff.Append(ptr.ToString("X"));
-        buff.Append(",s=");
-        buff.Append(type.ToString());
-        buff.Append(",k=");
-        buff.Append(shapeKey.ToString("X"));
-        buff.Append(",n=");
-        buff.Append(isNativeShape.ToString());
-        buff.Append(">");
-        return buff.ToString();
-    }
-}
-
     // Constraint type values as defined by Bullet
 public enum ConstraintType : int
 {
@@ -132,44 +46,6 @@ public enum ConstraintType : int
         MAX_CONSTRAINT_TYPE
 }
 
-// An allocated Bullet btConstraint
-public struct BulletConstraint
-{
-    public BulletConstraint(IntPtr xx)
-    {
-        ptr = xx;
-    }
-    public IntPtr ptr;
-}
-
-// An allocated HeightMapThing which holds various heightmap info.
-// Made a class rather than a struct so there would be only one
-//      instance of this and C# will pass around pointers rather
-//      than making copies.
-public class BulletHeightMapInfo
-{
-    public BulletHeightMapInfo(uint id, float[] hm, IntPtr xx) {
-        ID = id;
-        Ptr = xx;
-        heightMap = hm;
-        terrainRegionBase = Vector3.Zero;
-        minCoords = new Vector3(100f, 100f, 25f);
-        maxCoords = new Vector3(101f, 101f, 26f);
-        minZ = maxZ = 0f;
-        sizeX = sizeY = 256f;
-    }
-    public uint ID;
-    public IntPtr Ptr;
-    public float[] heightMap;
-    public Vector3 terrainRegionBase;
-    public Vector3 minCoords;
-    public Vector3 maxCoords;
-    public float sizeX, sizeY;
-    public float minZ, maxZ;
-    public BulletShape terrainShape;
-    public BulletBody terrainBody;
-}
-
 // ===============================================================================
 [StructLayout(LayoutKind.Sequential)]
 public struct ConvexHull
@@ -287,6 +163,8 @@ public struct ConfigurationParameters
     public float terrainFriction;
     public float terrainHitFraction;
     public float terrainRestitution;
+    public float terrainCollisionMargin;
+
     public float avatarFriction;
     public float avatarStandingFriction;
     public float avatarDensity;
@@ -296,6 +174,8 @@ public struct ConfigurationParameters
     public float avatarCapsuleHeight;
         public float avatarContactProcessingThreshold;
 
+    public float vehicleAngularDamping;
+
         public float maxPersistantManifoldPoolSize;
         public float maxCollisionAlgorithmPoolSize;
         public float shouldDisableContactPoolDynamicAllocation;
@@ -353,56 +233,35 @@ public enum CollisionFlags : uint
     CF_CHARACTER_OBJECT              = 1 << 4,
     CF_DISABLE_VISUALIZE_OBJECT      = 1 << 5,
     CF_DISABLE_SPU_COLLISION_PROCESS = 1 << 6,
-    // Following used by BulletSim to control collisions
+    // Following used by BulletSim to control collisions and updates
     BS_SUBSCRIBE_COLLISION_EVENTS    = 1 << 10,
     BS_FLOATS_ON_WATER               = 1 << 11,
+    BS_VEHICLE_COLLISIONS            = 1 << 12,
     BS_NONE                          = 0,
-    BS_ALL                           = 0xFFFFFFFF,
-
-    // These are the collision flags switched depending on physical state.
-    // The other flags are used for other things and should not be fooled with.
-    BS_ACTIVE = CF_STATIC_OBJECT
-                | CF_KINEMATIC_OBJECT
-                | CF_NO_CONTACT_RESPONSE
+    BS_ALL                           = 0xFFFFFFFF
 };
 
-// Values for collisions groups and masks
+// Values f collisions groups and masks
 public enum CollisionFilterGroups : uint
 {
     // Don't use the bit definitions!!  Define the use in a
     //   filter/mask definition below. This way collision interactions
-    //   are more easily debugged.
-    BNoneFilter              = 0,
-    BDefaultFilter           = 1 << 0,
-    BStaticFilter            = 1 << 1,
-    BKinematicFilter         = 1 << 2,
-    BDebrisFilter            = 1 << 3,
-    BSensorTrigger           = 1 << 4,
-    BCharacterFilter         = 1 << 5,
-    BAllFilter               = 0xFFFFFFFF,
+    //   are more easily found and debugged.
+    BNoneGroup              = 0,
+    BDefaultGroup           = 1 << 0,
+    BStaticGroup            = 1 << 1,
+    BKinematicGroup         = 1 << 2,
+    BDebrisGroup            = 1 << 3,
+    BSensorTrigger          = 1 << 4,
+    BCharacterGroup         = 1 << 5,
+    BAllGroup               = 0xFFFFFFFF,
     // Filter groups defined by BulletSim
-    BGroundPlaneFilter       = 1 << 10,
-    BTerrainFilter           = 1 << 11,
-    BRaycastFilter           = 1 << 12,
-    BSolidFilter             = 1 << 13,
-    BLinksetFilter           = 1 << 14,
-
-    // The collsion filters and masked are defined in one place -- don't want them scattered
-    AvatarFilter            = BCharacterFilter,
-    AvatarMask              = BAllFilter,
-    ObjectFilter            = BSolidFilter,
-    ObjectMask              = BAllFilter,
-    StaticObjectFilter      = BStaticFilter,
-    StaticObjectMask        = BAllFilter & ~BStaticFilter,   // static objects don't collide with each other
-    LinksetFilter           = BLinksetFilter,
-    LinksetMask             = BAllFilter & ~BLinksetFilter, // linkset objects don't collide with each other
-    VolumeDetectFilter      = BSensorTrigger,
-    VolumeDetectMask        = ~BSensorTrigger,
-    TerrainFilter           = BTerrainFilter,
-    TerrainMask             = BAllFilter & ~BStaticFilter,  // static objects on the ground don't collide
-    GroundPlaneFilter       = BGroundPlaneFilter,
-    GroundPlaneMask         = BAllFilter
-
+    BGroundPlaneGroup       = 1 << 10,
+    BTerrainGroup           = 1 << 11,
+    BRaycastGroup           = 1 << 12,
+    BSolidGroup             = 1 << 13,
+    // BLinksetGroup        = xx  // a linkset proper is either static or dynamic
+    BLinksetChildGroup      = 1 << 14,
 };
 
 // CFM controls the 'hardness' of the constraint. 0=fixed, 0..1=violatable. Default=0
@@ -429,7 +288,7 @@ public enum ConstraintParamAxis : int
 
 // ===============================================================================
 static class BulletSimAPI {
-
+// ===============================================================================
 // Link back to the managed code for outputting log messages
 [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
 public delegate void DebugLogCallback([MarshalAs(UnmanagedType.LPStr)]string msg);
@@ -482,6 +341,9 @@ public static extern IntPtr BuildNativeShape2(IntPtr world, ShapeData shapeData)
 public static extern bool IsNativeShape2(IntPtr shape);
 
 [DllImport("BulletSim", CallingConvention = CallingConvention.Cdecl), SuppressUnmanagedCodeSecurity]
+public static extern void SetShapeCollisionMargin(IntPtr shape, float margin);
+
+[DllImport("BulletSim", CallingConvention = CallingConvention.Cdecl), SuppressUnmanagedCodeSecurity]
 public static extern IntPtr BuildCapsuleShape2(IntPtr world, float radius, float height, Vector3 scale);
 
 [DllImport("BulletSim", CallingConvention = CallingConvention.Cdecl), SuppressUnmanagedCodeSecurity]
@@ -938,7 +800,7 @@ public static extern IntPtr GetConstraintRef2(IntPtr obj, int index);
 public static extern int GetNumConstraintRefs2(IntPtr obj);
 
 [DllImport("BulletSim", CallingConvention = CallingConvention.Cdecl), SuppressUnmanagedCodeSecurity]
-public static extern void SetCollisionFilterMask2(IntPtr body, uint filter, uint mask);
+public static extern bool SetCollisionGroupMask2(IntPtr body, uint filter, uint mask);
 
 // =====================================================================================
 // btCollisionShape entries
@@ -1000,13 +862,16 @@ public static extern void DumpRigidBody2(IntPtr sim, IntPtr collisionObject);
 public static extern void DumpCollisionShape2(IntPtr sim, IntPtr collisionShape);
 
 [DllImport("BulletSim", CallingConvention = CallingConvention.Cdecl), SuppressUnmanagedCodeSecurity]
+public static extern void DumpMapInfo2(IntPtr sim, IntPtr manInfo);
+
+[DllImport("BulletSim", CallingConvention = CallingConvention.Cdecl), SuppressUnmanagedCodeSecurity]
 public static extern void DumpConstraint2(IntPtr sim, IntPtr constrain);
 
 [DllImport("BulletSim", CallingConvention = CallingConvention.Cdecl), SuppressUnmanagedCodeSecurity]
-public static extern void DumpAllInfo2(IntPtr sim);
+public static extern void DumpActivationInfo2(IntPtr sim);
 
 [DllImport("BulletSim", CallingConvention = CallingConvention.Cdecl), SuppressUnmanagedCodeSecurity]
-public static extern void DumpMapInfo2(IntPtr sim, IntPtr manInfo);
+public static extern void DumpAllInfo2(IntPtr sim);
 
 [DllImport("BulletSim", CallingConvention = CallingConvention.Cdecl), SuppressUnmanagedCodeSecurity]
 public static extern void DumpPhysicsStatistics2(IntPtr sim);
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BulletSimData.cs b/OpenSim/Region/Physics/BulletSPlugin/BulletSimData.cs
new file mode 100755
index 0000000..662177f
--- /dev/null
+++ b/OpenSim/Region/Physics/BulletSPlugin/BulletSimData.cs
@@ -0,0 +1,278 @@
+/*
+ * Copyright (c) Contributors, http://opensimulator.org/
+ * See CONTRIBUTORS.TXT for a full list of copyright holders.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyrightD
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of the OpenSimulator Project nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+using System;
+using System.Collections.Generic;
+using System.Text;
+using OMV = OpenMetaverse;
+
+namespace OpenSim.Region.Physics.BulletSPlugin
+{
+// Classes to allow some type checking for the API
+// These hold pointers to allocated objects in the unmanaged space.
+
+// The physics engine controller class created at initialization
+public struct BulletSim
+{
+    public BulletSim(uint worldId, BSScene bss, IntPtr xx)
+    {
+        ptr = xx;
+        worldID = worldId;
+        physicsScene = bss;
+    }
+    public IntPtr ptr;
+    public uint worldID;
+    // The scene is only in here so very low level routines have a handle to print debug/error messages
+    public BSScene physicsScene;
+}
+
+// An allocated Bullet btRigidBody
+public struct BulletBody
+{
+    public BulletBody(uint id) : this(id, IntPtr.Zero)
+    {
+    }
+    public BulletBody(uint id, IntPtr xx)
+    {
+        ID = id;
+        ptr = xx;
+        collisionType = CollisionType.Static;
+    }
+    public IntPtr ptr;
+    public uint ID;
+    public CollisionType collisionType;
+
+    public void Clear()
+    {
+        ptr = IntPtr.Zero;
+    }
+    public bool HasPhysicalBody { get { return ptr != IntPtr.Zero; } }
+
+    // Apply the specificed collision mask into the physical world
+    public void ApplyCollisionMask()
+    {
+        // Should assert the body has been added to the physical world.
+        // (The collision masks are stored in the collision proxy cache which only exists for
+        //    a collision body that is in the world.)
+        BulletSimAPI.SetCollisionGroupMask2(ptr,
+                                BulletSimData.CollisionTypeMasks[collisionType].group,
+                                BulletSimData.CollisionTypeMasks[collisionType].mask);
+    }
+
+    public override string ToString()
+    {
+        StringBuilder buff = new StringBuilder();
+        buff.Append("<id=");
+        buff.Append(ID.ToString());
+        buff.Append(",p=");
+        buff.Append(ptr.ToString("X"));
+        buff.Append(",c=");
+        buff.Append(collisionType);
+        buff.Append(">");
+        return buff.ToString();
+    }
+}
+
+public struct BulletShape
+{
+    public BulletShape(IntPtr xx) : this(xx, BSPhysicsShapeType.SHAPE_UNKNOWN)
+    {
+    }
+    public BulletShape(IntPtr xx, BSPhysicsShapeType typ)
+    {
+        ptr = xx;
+        type = typ;
+        shapeKey = (System.UInt64)FixedShapeKey.KEY_NONE;
+        isNativeShape = false;
+    }
+    public IntPtr ptr;
+    public BSPhysicsShapeType type;
+    public System.UInt64 shapeKey;
+    public bool isNativeShape;
+
+    public void Clear()
+    {
+        ptr = IntPtr.Zero;
+    }
+    public bool HasPhysicalShape { get { return ptr != IntPtr.Zero; } }
+
+    public override string ToString()
+    {
+        StringBuilder buff = new StringBuilder();
+        buff.Append("<p=");
+        buff.Append(ptr.ToString("X"));
+        buff.Append(",s=");
+        buff.Append(type.ToString());
+        buff.Append(",k=");
+        buff.Append(shapeKey.ToString("X"));
+        buff.Append(",n=");
+        buff.Append(isNativeShape.ToString());
+        buff.Append(">");
+        return buff.ToString();
+    }
+}
+
+// An allocated Bullet btConstraint
+public struct BulletConstraint
+{
+    public BulletConstraint(IntPtr xx)
+    {
+        ptr = xx;
+    }
+    public IntPtr ptr;
+
+    public void Clear()
+    {
+        ptr = IntPtr.Zero;
+    }
+    public bool HasPhysicalConstraint { get { return ptr != IntPtr.Zero; } }
+}
+
+// An allocated HeightMapThing which holds various heightmap info.
+// Made a class rather than a struct so there would be only one
+//      instance of this and C# will pass around pointers rather
+//      than making copies.
+public class BulletHeightMapInfo
+{
+    public BulletHeightMapInfo(uint id, float[] hm, IntPtr xx) {
+        ID = id;
+        Ptr = xx;
+        heightMap = hm;
+        terrainRegionBase = OMV.Vector3.Zero;
+        minCoords = new OMV.Vector3(100f, 100f, 25f);
+        maxCoords = new OMV.Vector3(101f, 101f, 26f);
+        minZ = maxZ = 0f;
+        sizeX = sizeY = 256f;
+    }
+    public uint ID;
+    public IntPtr Ptr;
+    public float[] heightMap;
+    public OMV.Vector3 terrainRegionBase;
+    public OMV.Vector3 minCoords;
+    public OMV.Vector3 maxCoords;
+    public float sizeX, sizeY;
+    public float minZ, maxZ;
+    public BulletShape terrainShape;
+    public BulletBody terrainBody;
+}
+
+// The general class of collsion object.
+public enum CollisionType
+{
+    Avatar,
+    Groundplane,
+    Terrain,
+    Static,
+    Dynamic,
+    VolumeDetect,
+    // Linkset, // A linkset should be either Static or Dynamic
+    LinksetChild,
+    Unknown
+};
+
+// Hold specification of group and mask collision flags for a CollisionType
+public struct CollisionTypeFilterGroup
+{
+    public CollisionTypeFilterGroup(CollisionType t, uint g, uint m)
+    {
+        type = t;
+        group = g;
+        mask = m;
+    }
+    public CollisionType type;
+    public uint group;
+    public uint mask;
+};
+
+    /* NOTE: old definitions kept for reference. Delete when things are working.
+    // The collsion filters and masked are defined in one place -- don't want them scattered
+    AvatarGroup             = BCharacterGroup,
+    AvatarMask              = BAllGroup,
+    ObjectGroup             = BSolidGroup,
+    ObjectMask              = BAllGroup,
+    StaticObjectGroup       = BStaticGroup,
+    StaticObjectMask        = AvatarGroup | ObjectGroup,    // static things don't interact with much
+    LinksetGroup            = BLinksetGroup,
+    LinksetMask             = BAllGroup,
+    LinksetChildGroup       = BLinksetChildGroup,
+    LinksetChildMask        = BNoneGroup,   // Linkset children disappear from the world
+    VolumeDetectGroup       = BSensorTrigger,
+    VolumeDetectMask        = ~BSensorTrigger,
+    TerrainGroup            = BTerrainGroup,
+    TerrainMask             = BAllGroup & ~BStaticGroup,  // static objects on the ground don't collide
+    GroundPlaneGroup        = BGroundPlaneGroup,
+    GroundPlaneMask         = BAllGroup
+    */
+
+public static class BulletSimData
+{
+
+// Map of collisionTypes to flags for collision groups and masks.
+// As mentioned above, don't use the CollisionFilterGroups definitions directly in the code
+//     but, instead, use references to this dictionary. Finding and debugging
+//     collision flag problems will be made easier.
+public static Dictionary<CollisionType, CollisionTypeFilterGroup> CollisionTypeMasks 
+            = new Dictionary<CollisionType, CollisionTypeFilterGroup>()
+{
+    { CollisionType.Avatar, 
+                new CollisionTypeFilterGroup(CollisionType.Avatar, 
+                                (uint)CollisionFilterGroups.BCharacterGroup, 
+                                (uint)CollisionFilterGroups.BAllGroup)
+    },
+    { CollisionType.Groundplane, 
+                new CollisionTypeFilterGroup(CollisionType.Groundplane, 
+                                (uint)CollisionFilterGroups.BGroundPlaneGroup, 
+                                (uint)CollisionFilterGroups.BAllGroup)
+    },
+    { CollisionType.Terrain, 
+                new CollisionTypeFilterGroup(CollisionType.Terrain, 
+                                (uint)CollisionFilterGroups.BTerrainGroup, 
+                                (uint)(CollisionFilterGroups.BAllGroup & ~CollisionFilterGroups.BStaticGroup))
+    },
+    { CollisionType.Static, 
+                new CollisionTypeFilterGroup(CollisionType.Static, 
+                                (uint)CollisionFilterGroups.BStaticGroup, 
+                                (uint)(CollisionFilterGroups.BCharacterGroup | CollisionFilterGroups.BSolidGroup))
+    },
+    { CollisionType.Dynamic, 
+                new CollisionTypeFilterGroup(CollisionType.Dynamic, 
+                                (uint)CollisionFilterGroups.BSolidGroup, 
+                                (uint)(CollisionFilterGroups.BAllGroup))
+    },
+    { CollisionType.VolumeDetect, 
+                new CollisionTypeFilterGroup(CollisionType.VolumeDetect, 
+                                (uint)CollisionFilterGroups.BSensorTrigger, 
+                                (uint)(~CollisionFilterGroups.BSensorTrigger))
+    },
+    { CollisionType.LinksetChild,
+                new CollisionTypeFilterGroup(CollisionType.LinksetChild, 
+                                (uint)CollisionFilterGroups.BTerrainGroup, 
+                                (uint)(CollisionFilterGroups.BNoneGroup))
+    },
+};
+
+}
+}
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt b/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
new file mode 100755
index 0000000..c084ab4
--- /dev/null
+++ b/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
@@ -0,0 +1,218 @@
+CURRENT PRIORITIES
+=================================================
+Smooth avatar movement with motor
+        Should motor update be all at taint-time?
+Enable vehicle border crossings (at least as poorly as ODE)
+        Terrain skirts
+        Avatar created in previous region and not new region when crossing border
+        Vehicle recreated in new sim at small Z value (offset from root value?) (DONE)
+Vehicle movement on terrain smoothness
+Vehicle script tuning/debugging
+        Avanti speed script
+        Weapon shooter script
+limitMotorUp calibration (more down?)
+
+CRASHES
+=================================================
+20121129.1411: editting/moving phys object across region boundries causes crash
+    getPos-> btRigidBody::upcast -> getBodyType -> BOOM
+20121128.1600: mesh object not rezzing (no physics mesh).
+    Causes many errors. Doesn't stop after first error with box shape.
+    Eventually crashes when deleting the object.
+20121206.1434: rez Sam-pan into OSGrid BulletSim11 region
+        Immediate simulator crash. Mono does not output any stacktrace and
+        log just stops after reporting taint-time linking of the linkset.
+
+VEHICLES TODO LIST:
+=================================================
+Border crossing with linked vehicle causes crash
+Vehicles (Move smoothly)
+Add vehicle collisions so IsColliding is properly reported.
+        Needed for banking, limitMotorUp, movementLimiting, ...
+Some vehicles should not be able to turn if no speed or off ground.
+Cannot edit/move a vehicle being ridden: it jumps back to the origional position.
+Neb car jiggling left and right
+        Happens on terrain and any other mesh object. Flat cubes are much smoother.
+        This has been reduced but not eliminated.
+Implement referenceFrame for all the motion routines.
+Angular motion around Z moves the vehicle in world Z and not vehicle Z in ODE.
+        Verify that angular motion specified around Z moves in the vehicle coordinates.
+Verify llGetVel() is returning a smooth and good value for vehicle movement.
+llGetVel() should return the root's velocity if requested in a child prim.
+Implement function efficiency for lineaar and angular motion.
+After getting off a vehicle, the root prim is phantom (can be walked through)
+    Need to force a position update for the root prim after compound shape destruction
+Linkset explosion after three "rides" on Nebadon lite vehicle (LinksetConstraint)
+For limitMotorUp, use raycast down to find if vehicle is in the air.
+Remove vehicle angular velocity zeroing in BSPrim.UpdateProperties().
+        A kludge that isn't fixing the real problem of Bullet adding extra motion.
+Incorporate inter-relationship of angular corrections. For instance, angularDeflection
+        and angularMotorUp will compute same X or Y correction. When added together
+        creates over-correction and over-shoot and wabbling.
+
+BULLETSIM TODO LIST:
+=================================================
+Revisit CollisionMargin. Builders notice the 0.04 spacing between prims.
+Duplicating a physical prim causes old prim to jump away
+        Dup a phys prim and the original become unselected and thus interacts w/ selected prim.
+Scenes with hundred of thousands of static objects take a lot of physics CPU time.
+BSPrim.Force should set a continious force on the prim. The force should be
+        applied each tick.  Some limits?
+Gun sending shooter flying.
+Collision margin (gap between physical objects lying on each other)
+Boundry checking (crashes related to crossing boundry)
+    Add check for border edge position for avatars and objects.
+    Verify the events are created for border crossings.
+Avatar rotation (check out changes to ScenePresence for physical rotation)
+Avatar running (what does phys engine need to do?)
+Small physical objects do not interact correctly
+    Create chain of .5x.5x.1 torui and make all but top physical so to hang.
+        The chain will fall apart and pairs will dance around on ground
+    Chains of 1x1x.2 will stay connected but will dance.
+    Chains above 2x2x.4 are move stable and get stablier as torui get larger.
+Add PID motor for avatar movement (slow to stop, ...)
+setForce should set a constant force. Different than AddImpulse.
+Implement raycast.
+Implement ShapeCollection.Dispose()
+Implement water as a plain so raycasting and collisions can happen with same.
+Add osGetPhysicsEngineName() so scripters can tell whether BulletSim or ODE
+        Also osGetPhysicsEngineVerion() maybe.
+Linkset.Position and Linkset.Orientation requre rewrite to properly return
+        child position. LinksetConstraint acts like it's at taint time!!
+Implement LockAngularMotion -- implements llSetStatus(ROTATE_AXIS_*, T/F)
+Should the different PID factors have non-equal contributions for different
+        values of Efficiency?
+
+LINKSETS
+======================================================
+Linksets should allow collisions to individual children
+        Add LocalID to children shapes in LinksetCompound and create events for individuals
+LinksetCompound: when one of the children changes orientation (like tires
+        turning on a vehicle, the whole compound object is rebuilt. Optimize this
+        so orientation/position of individual children can change without a rebuild.
+Verify/think through scripts in children of linksets. What do they reference
+        and return when getting position, velocity, ...
+Confirm constraint linksets still work after making all the changes for compound linksets.
+Add 'changed' flag or similar to reduce the number of times a linkset is rebuilt.
+        For compound linksets, add ability to remove or reposition individual child shapes.
+Disable activity of passive linkset children.
+        Since the linkset is a compound object, the old prims are left lying
+        around and need to be phantomized so they don't collide, ...
+Speed up creation of large physical linksets
+        For instance, sitting in Neb's car (130 prims) takes several seconds to become physical.
+        REALLY bad for very large physical linksets (freezes the sim for many seconds).
+Eliminate collisions between objects in a linkset. (LinksetConstraint)
+    Have UserPointer point to struct with localID and linksetID?
+    Objects in original linkset still collide with each other?
+
+MORE
+======================================================
+Test avatar walking up stairs. How does compare with SL.
+    Radius of the capsule affects ability to climb edges.
+Debounce avatar contact so legs don't keep folding up when standing.
+Implement LSL physics controls. Like STATUS_ROTATE_X.
+Add border extensions to terrain to help region crossings and objects leaving region.
+
+Performance test with lots of avatars. Can BulletSim support a thousand?
+Optimize collisions in C++: only send up to the object subscribed to collisions.
+    Use collision subscription and remove the collsion(A,B) and collision(B,A)
+Check whether SimMotionState needs large if statement (see TODO).
+
+Implement 'top colliders' info.
+Avatar jump
+Performance measurement and changes to make quicker.
+Implement detailed physics stats (GetStats()).
+
+Measure performance improvement from hulls
+Test not using ghost objects for volume detect implementation.
+Performance of closures and delegates for taint processing
+        Are there faster ways?
+        Is any slowdown introduced by the existing implementation significant?
+Is there are more efficient method of implementing pre and post step actions?
+        See http://www.codeproject.com/Articles/29922/Weak-Events-in-C
+
+Physics Arena central pyramid: why is one side permiable?
+
+INTERNAL IMPROVEMENT/CLEANUP
+=================================================
+Consider moving prim/character body and shape destruction in destroy()
+        to postTimeTime rather than protecting all the potential sets that
+        might have been queued up.
+Remove unused fields from ShapeData (not used in API2)
+Remove unused fields from pinned memory shared parameter block
+        Create parameter variables in BSScene to replace same.
+Breakout code for mesh/hull/compound/native into separate BSShape* classes
+    Standardize access to building and reference code.
+        The skeleton classes are in the sources but are not complete or linked in.
+Make BSBody and BSShape real classes to centralize creation/changin/destruction
+        Convert state and parameter calls from BulletSimAPI direct calls to
+                calls on BSBody and BSShape
+Generalize Dynamics and PID with standardized motors.
+Generalize Linkset and vehicles into PropertyManagers
+    Methods for Refresh, RemoveBodyDependencies, RestoreBodyDependencies
+        Potentially add events for shape destruction, etc.
+Complete implemention of preStepActions
+        Replace vehicle step call with prestep event.
+        Is there a need for postStepActions? postStepTaints?
+Implement linkset by setting position of children when root updated. (LinksetManual)
+        Linkset implementation using manual prim movement.
+LinkablePrim class? Would that simplify/centralize the linkset logic?
+BSScene.UpdateParameterSet() is broken. How to set params on objects?
+Remove HeightmapInfo from terrain specification
+    Since C++ code does not need terrain height, this structure et al are not needed.
+Add floating motor for BS_FLOATS_ON_WATER so prim and avatar will
+    bob at the water level. BSPrim.PositionSanityCheck().
+Should taints check for existance or activeness of target?
+        When destroying linksets/etc, taints can be generated for objects that are
+        actually gone when the taint happens. Crashes don't happen because the taint closure
+        keeps the object from being freed, but that is just an accident.
+        Possibly have and 'active' flag that is checked by the taint processor?
+
+THREADING
+=================================================
+Do taint action immediately if not actually executing Bullet.
+        Add lock around Bullet execution and just do taint actions if simulation is not happening.
+
+DONE DONE DONE DONE
+=================================================
+Cleanup code in BSDynamics by using motors. (Resolution: started)
+Consider implementing terrain with a mesh rather than heightmap. (Resolution: done)
+    Would have better and adjustable resolution.
+Build terrain mesh so heighmap is height of the center of the square meter.
+    Resolution: NOT DONE: SL and ODE define meter square as being at one corner with one diagional.
+Terrain as mesh. (Resolution: done)
+How are static linksets seen by the physics engine?
+    Resolution: they are not linked in physics. When moved, all the children are repositioned.
+Convert BSCharacter to use all API2 (Resolution: done)
+Avatar pushing difficult (too heavy?)
+Use asset service passed to BulletSim to get sculptie bodies, etc. (Resolution: done)
+Remove old code in DLL (all non-API2 stuff). (Resolution: done)
+Measurements of mega-physical prim performance (with graph) (Resolution: done, email)
+Debug Bullet internal stats output (why is timing all wrong?)
+        Resolution: Bullet stats logging only works with a single instance of Bullet (one region).
+Implement meshes or just verify that they work. (Resolution: they do!)
+Do prim hash codes work for sculpties and meshes? (Resolution: yes)
+Linkset implementation using compound shapes. (Resolution: implemented LinksetCompound)
+    Compound shapes will need the LocalID in the shapes and collision
+    processing to get it from there.
+Light cycle not banking (Resolution: It doesn't. Banking is roll adding yaw.)
+Package Bullet source mods for Bullet internal stats output
+        (Resolution: move code into WorldData.h rather than relying on patches)
+Single prim vehicles don't seem to properly vehiclize.
+        (Resolution: mass was not getting set properly for single prim linksets)
+Add material type linkage and input all the material property definitions.
+        Skeleton classes and table are in the sources but are not filled or used.
+        (Resolution: 
+Neb vehicle taking > 25ms of physics time!!
+        (Resolution: compound linksets were being rebuild WAY too often)
+Avatar height off after unsitting (floats off ground)
+        Editting appearance then moving restores.
+        Must not be initializing height when recreating capsule after unsit.
+        (Resolution: confusion of scale vs size for native objects removed)
+Light cycle falling over when driving (Resolution: implemented angularMotorUp)
+Should vehicle angular/linear movement friction happen after all the components
+        or does it only apply to the basic movement?
+        (Resolution: friction added before returning newly computed motor value.
+        What is expected by some vehicles (turning up friction to moderate speed))
+Tune terrain/object friction to be closer to SL.
+        (Resolution: added material type with friction and resolution)
diff --git a/OpenSim/Region/Physics/ChOdePlugin/ODEPrim.cs b/OpenSim/Region/Physics/ChOdePlugin/ODEPrim.cs
index 8de70ef..ba24aa7 100644
--- a/OpenSim/Region/Physics/ChOdePlugin/ODEPrim.cs
+++ b/OpenSim/Region/Physics/ChOdePlugin/ODEPrim.cs
@@ -2190,7 +2190,7 @@ namespace OpenSim.Region.Physics.OdePlugin
                         convex = false;
                     try
                     {
-                        _mesh = _parent_scene.mesher.CreateMesh(m_primName, _pbs, _size, (int)LevelOfDetail.High, true,convex,false);
+                        _mesh = _parent_scene.mesher.CreateMesh(m_primName, _pbs, _size, (int)LevelOfDetail.High, true,false,convex,false);
                     }
                     catch
                     {
@@ -2557,7 +2557,7 @@ namespace OpenSim.Region.Physics.OdePlugin
 
                 try
                 {
-                    mesh = _parent_scene.mesher.CreateMesh(oldname, _pbs, _size, (int)LevelOfDetail.High, true, convex,false);
+                    mesh = _parent_scene.mesher.CreateMesh(oldname, _pbs, _size, (int)LevelOfDetail.High, true, false,convex,false);
                 }
                 catch
                 {
diff --git a/OpenSim/Region/Physics/Manager/IMesher.cs b/OpenSim/Region/Physics/Manager/IMesher.cs
index ecc2918..df980ab 100644
--- a/OpenSim/Region/Physics/Manager/IMesher.cs
+++ b/OpenSim/Region/Physics/Manager/IMesher.cs
@@ -37,7 +37,7 @@ namespace OpenSim.Region.Physics.Manager
     {
         IMesh CreateMesh(String primName, PrimitiveBaseShape primShape, Vector3 size, float lod);
         IMesh CreateMesh(String primName, PrimitiveBaseShape primShape, Vector3 size, float lod, bool isPhysical);
-        IMesh CreateMesh(String primName, PrimitiveBaseShape primShape, Vector3 size, float lod, bool isPhysical, bool convex, bool forOde);
+        IMesh CreateMesh(String primName, PrimitiveBaseShape primShape, Vector3 size, float lod, bool isPhysical, bool shouldCache, bool convex, bool forOde);
         IMesh GetMesh(String primName, PrimitiveBaseShape primShape, Vector3 size, float lod, bool isPhysical, bool convex);
         void ReleaseMesh(IMesh mesh);
         void ExpireReleaseMeshs();
diff --git a/OpenSim/Region/Physics/Manager/PhysicsActor.cs b/OpenSim/Region/Physics/Manager/PhysicsActor.cs
index 9338130..e2789d6 100644
--- a/OpenSim/Region/Physics/Manager/PhysicsActor.cs
+++ b/OpenSim/Region/Physics/Manager/PhysicsActor.cs
@@ -349,17 +349,20 @@ namespace OpenSim.Region.Physics.Manager
         }
 
         /// <summary>
-        /// Velocity of this actor.
+        /// The desired velocity of this actor.
         /// </summary>
         /// <remarks>
         /// Setting this provides a target velocity for physics scene updates.
-        /// Getting this returns the velocity calculated by physics scene updates, using factors such as target velocity,
-        /// time to accelerate and collisions.
+        /// Getting this returns the last set target. Fetch Velocity to get the current velocity.
         /// </remarks>
+        protected Vector3 m_targetVelocity;
         public virtual Vector3 TargetVelocity
         {
-            get { return Velocity; }
-            set { Velocity = value; }
+            get { return m_targetVelocity; }
+            set {
+                m_targetVelocity = value;
+                Velocity = m_targetVelocity;
+            }
         }
 
         public abstract Vector3 Velocity { get; set; }
diff --git a/OpenSim/Region/Physics/Manager/ZeroMesher.cs b/OpenSim/Region/Physics/Manager/ZeroMesher.cs
index 16846e6..80ecf66 100644
--- a/OpenSim/Region/Physics/Manager/ZeroMesher.cs
+++ b/OpenSim/Region/Physics/Manager/ZeroMesher.cs
@@ -64,16 +64,21 @@ namespace OpenSim.Region.Physics.Manager
     {
         public IMesh CreateMesh(String primName, PrimitiveBaseShape primShape, Vector3 size, float lod)
         {
-            return CreateMesh(primName, primShape, size, lod, false);
+            return CreateMesh(primName, primShape, size, lod, false, false);
         }
 
-        public IMesh CreateMesh(String primName, PrimitiveBaseShape primShape, Vector3 size, float lod, bool isPhysical, bool convex,bool forOde)
+        public IMesh CreateMesh(String primName, PrimitiveBaseShape primShape, Vector3 size, float lod, bool isPhysical, bool shouldCache, bool convex,bool forOde)
         {
             return CreateMesh(primName, primShape, size, lod, false);
         }
 
         public IMesh CreateMesh(String primName, PrimitiveBaseShape primShape, Vector3 size, float lod, bool isPhysical)
         {
+            return CreateMesh(primName, primShape, size, lod, false, false);
+        }
+
+        public IMesh CreateMesh(String primName, PrimitiveBaseShape primShape, Vector3 size, float lod, bool isPhysical, bool shouldCache)
+        {
             // Remove the reference to the encoded JPEG2000 data so it can be GCed
             primShape.SculptData = OpenMetaverse.Utils.EmptyBytes;
 
diff --git a/OpenSim/Region/Physics/Meshing/Meshmerizer.cs b/OpenSim/Region/Physics/Meshing/Meshmerizer.cs
index f629c4d..d181b78 100644
--- a/OpenSim/Region/Physics/Meshing/Meshmerizer.cs
+++ b/OpenSim/Region/Physics/Meshing/Meshmerizer.cs
@@ -321,6 +321,9 @@ namespace OpenSim.Region.Physics.Meshing
 
             if (primShape.SculptData.Length <= 0)
             {
+                // XXX: At the moment we can not log here since ODEPrim, for instance, ends up triggering this
+                // method twice - once before it has loaded sculpt data from the asset service and once afterwards.
+                // The first time will always call with unloaded SculptData if this needs to be uploaded.
 //                m_log.ErrorFormat("[MESH]: asset data for {0} is zero length", primName);
                 return false;
             }
@@ -699,16 +702,21 @@ namespace OpenSim.Region.Physics.Meshing
 
         public IMesh CreateMesh(String primName, PrimitiveBaseShape primShape, Vector3 size, float lod)
         {
-            return CreateMesh(primName, primShape, size, lod, false);
+            return CreateMesh(primName, primShape, size, lod, false, true);
         }
 
-        public IMesh CreateMesh(String primName, PrimitiveBaseShape primShape, Vector3 size, float lod, bool isPhysical, bool convex, bool forOde)
+        public IMesh CreateMesh(String primName, PrimitiveBaseShape primShape, Vector3 size, float lod, bool isPhysical, bool shouldCache, bool convex, bool forOde)
         {
             return CreateMesh(primName, primShape, size, lod, false);
         }
 
         public IMesh CreateMesh(String primName, PrimitiveBaseShape primShape, Vector3 size, float lod, bool isPhysical)
         {
+            return CreateMesh(primName, primShape, size, lod, isPhysical, true);
+        }
+
+        public IMesh CreateMesh(String primName, PrimitiveBaseShape primShape, Vector3 size, float lod, bool isPhysical, bool shouldCache)
+        {
 #if SPAM
             m_log.DebugFormat("[MESH]: Creating mesh for {0}", primName);
 #endif
@@ -718,9 +726,12 @@ namespace OpenSim.Region.Physics.Meshing
 
             // If this mesh has been created already, return it instead of creating another copy
             // For large regions with 100k+ prims and hundreds of copies of each, this can save a GB or more of memory
-            key = primShape.GetMeshKey(size, lod);
-            if (m_uniqueMeshes.TryGetValue(key, out mesh))
-                return mesh;
+            if (shouldCache)
+            {
+                key = primShape.GetMeshKey(size, lod);
+                if (m_uniqueMeshes.TryGetValue(key, out mesh))
+                    return mesh;
+            }
 
             if (size.X < 0.01f) size.X = 0.01f;
             if (size.Y < 0.01f) size.Y = 0.01f;
@@ -743,7 +754,10 @@ namespace OpenSim.Region.Physics.Meshing
                 // trim the vertex and triangle lists to free up memory
                 mesh.TrimExcess();
 
-                m_uniqueMeshes.Add(key, mesh);
+                if (shouldCache)
+                {
+                    m_uniqueMeshes.Add(key, mesh);
+                }
             }
 
             return mesh;
diff --git a/OpenSim/Region/Physics/OdePlugin/ODEPrim.cs b/OpenSim/Region/Physics/OdePlugin/ODEPrim.cs
index a59f63f..d09aa62 100644
--- a/OpenSim/Region/Physics/OdePlugin/ODEPrim.cs
+++ b/OpenSim/Region/Physics/OdePlugin/ODEPrim.cs
@@ -3367,6 +3367,11 @@ Console.WriteLine(" JointCreateFixed");
                 _pbs.SculptData = new byte[asset.Data.Length];
                 asset.Data.CopyTo(_pbs.SculptData, 0);
 //                m_assetFailed = false;
+
+//                m_log.DebugFormat(
+//                    "[ODE PRIM]: Received mesh/sculpt data asset {0} with {1} bytes for {2} at {3} in {4}", 
+//                    _pbs.SculptTexture, _pbs.SculptData.Length, Name, _position, _parent_scene.Name);
+
                 m_taintshape = true;
                _parent_scene.AddPhysicsActorTaint(this);
             }
diff --git a/OpenSim/Region/Physics/OdePlugin/Tests/ODETestClass.cs b/OpenSim/Region/Physics/OdePlugin/Tests/ODETestClass.cs
index cbc6b95..16404c6 100644
--- a/OpenSim/Region/Physics/OdePlugin/Tests/ODETestClass.cs
+++ b/OpenSim/Region/Physics/OdePlugin/Tests/ODETestClass.cs
@@ -32,13 +32,14 @@ using OpenMetaverse;
 using OpenSim.Framework;
 using OpenSim.Region.Physics.Manager;
 using OpenSim.Region.Physics.OdePlugin;
+using OpenSim.Tests.Common;
 using log4net;
 using System.Reflection;
 
 namespace OpenSim.Region.Physics.OdePlugin.Tests
 {
     [TestFixture]
-    public class ODETestClass
+    public class ODETestClass : OpenSimTestCase
     {
         private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
 
diff --git a/OpenSim/Region/Physics/UbitMeshing/Meshmerizer.cs b/OpenSim/Region/Physics/UbitMeshing/Meshmerizer.cs
index 6e1a105..00cbfbd 100644
--- a/OpenSim/Region/Physics/UbitMeshing/Meshmerizer.cs
+++ b/OpenSim/Region/Physics/UbitMeshing/Meshmerizer.cs
@@ -1031,12 +1031,12 @@ namespace OpenSim.Region.Physics.Meshing
 
         public IMesh CreateMesh(String primName, PrimitiveBaseShape primShape, Vector3 size, float lod)
         {
-            return CreateMesh(primName, primShape, size, lod, false,false,false);
+            return CreateMesh(primName, primShape, size, lod, false,false,false,false);
         }
 
         public IMesh CreateMesh(String primName, PrimitiveBaseShape primShape, Vector3 size, float lod, bool isPhysical)
         {
-            return CreateMesh(primName, primShape, size, lod, false,false,false);
+            return CreateMesh(primName, primShape, size, lod, false,false,false,false);
         }
 
         public IMesh GetMesh(String primName, PrimitiveBaseShape primShape, Vector3 size, float lod, bool isPhysical, bool convex)
@@ -1080,7 +1080,7 @@ namespace OpenSim.Region.Physics.Meshing
 
         private static Vector3 m_MeshUnitSize = new Vector3(1.0f, 1.0f, 1.0f);
         
-        public IMesh CreateMesh(String primName, PrimitiveBaseShape primShape, Vector3 size, float lod, bool isPhysical, bool convex, bool forOde)
+        public IMesh CreateMesh(String primName, PrimitiveBaseShape primShape, Vector3 size, float lod, bool isPhysical, bool shouldCache, bool convex, bool forOde)
         {
 #if SPAM
             m_log.DebugFormat("[MESH]: Creating mesh for {0}", primName);
diff --git a/OpenSim/Region/Physics/UbitOdePlugin/ODEMeshWorker.cs b/OpenSim/Region/Physics/UbitOdePlugin/ODEMeshWorker.cs
index 5030cec..0df71eb 100644
--- a/OpenSim/Region/Physics/UbitOdePlugin/ODEMeshWorker.cs
+++ b/OpenSim/Region/Physics/UbitOdePlugin/ODEMeshWorker.cs
@@ -448,7 +448,7 @@ namespace OpenSim.Region.Physics.OdePlugin
                 else
                 {
                     repData.meshState = MeshState.needMesh;
-                    mesh = m_mesher.CreateMesh(actor.Name, pbs, size, clod, true, convex, true);
+                    mesh = m_mesher.CreateMesh(actor.Name, pbs, size, clod, true, false, convex, true);
                     if (mesh == null)
                     {
                         repData.meshState = MeshState.MeshFailed;
@@ -513,7 +513,7 @@ namespace OpenSim.Region.Physics.OdePlugin
                     clod = (int)LevelOfDetail.Low;
             }
 
-            mesh = m_mesher.CreateMesh(actor.Name, pbs, size, clod, true, convex, true);
+            mesh = m_mesher.CreateMesh(actor.Name, pbs, size, clod, true, false, convex, true);
    
             if (mesh == null)
             {
@@ -929,4 +929,4 @@ namespace OpenSim.Region.Physics.OdePlugin
                     repData.actor.Name);
         }
     }
-}
\ No newline at end of file
+}