Merge branch 'master' of /home/opensim/var/repo/opensim

16 files changed, 314 insertions, 102 deletions

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs b/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
index 21aa9be..83c78f6 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
@@ -124,7 +124,9 @@ 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();
         });
     }
 
@@ -194,8 +196,11 @@ public sealed class BSCharacter : BSPhysObject
 
             PhysicsScene.TaintedObject("BSCharacter.setSize", delegate()
             {
-                BulletSimAPI.SetLocalScaling2(PhysShape.ptr, Scale);
-                UpdatePhysicalMassProperties(RawMass);
+                if (PhysShape.HasPhysicalShape)
+                {
+                    BulletSimAPI.SetLocalScaling2(PhysShape.ptr, Scale);
+                    UpdatePhysicalMassProperties(RawMass);
+                }
             });
 
         }
@@ -236,7 +241,8 @@ public sealed class BSCharacter : BSPhysObject
         // 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 +251,13 @@ 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 +282,8 @@ 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);
             });
         }
     }
@@ -332,7 +342,8 @@ 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 +370,8 @@ 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);
             });
         }
     }
@@ -398,7 +410,8 @@ 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 +419,8 @@ 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 +457,11 @@ 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);
+                }
             });
         }
     }
@@ -517,10 +534,13 @@ 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);
+                }
             });
         }
     }
@@ -553,7 +573,8 @@ public sealed class BSCharacter : BSPhysObject
             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 +620,8 @@ 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
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 fa3110c..82e829e 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
@@ -570,8 +570,8 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                 BulletSimAPI.SetMassProps2(Prim.PhysBody.ptr, m_vehicleMass, localInertia);
                 BulletSimAPI.UpdateInertiaTensor2(Prim.PhysBody.ptr);
 
-                VDetailLog("{0},BSDynamics.Refresh,frict={1},inert={2},aDamp={3}",
-                                Prim.LocalID, friction, localInertia, angularDamping);
+                VDetailLog("{0},BSDynamics.Refresh,mass={1},frict={2},inert={3},aDamp={4}",
+                                Prim.LocalID, m_vehicleMass, friction, localInertia, angularDamping);
             }
             else
             {
@@ -818,6 +818,8 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                             + hoverContribution
                             + limitMotorUpContribution;
 
+            Vector3 newForce = buoyancyContribution;
+
             // If not changing some axis, reduce out velocity
             if ((m_flags & (VehicleFlag.NO_X)) != 0)
                 newVelocity.X = 0;
@@ -845,7 +847,7 @@ namespace OpenSim.Region.Physics.BulletSPlugin
             VehicleVelocity = newVelocity;
 
             // Other linear forces are applied as forces.
-            Vector3 totalDownForce = buoyancyContribution * m_vehicleMass;
+            Vector3 totalDownForce = newForce * m_vehicleMass;
             if (!totalDownForce.ApproxEquals(Vector3.Zero, 0.01f))
             {
                 VehicleAddForce(totalDownForce);
@@ -991,8 +993,8 @@ namespace OpenSim.Region.Physics.BulletSPlugin
 
             if ((m_flags & (VehicleFlag.LIMIT_MOTOR_UP)) != 0)
             {
-                // If the vehicle is motoring into the sky, get it going back down.
-                float distanceAboveGround = VehiclePosition.Z - GetTerrainHeight(VehiclePosition);
+                float targetHeight = Type == Vehicle.TYPE_BOAT ? GetWaterLevel(VehiclePosition) : GetTerrainHeight(VehiclePosition);
+                float distanceAboveGround = VehiclePosition.Z - targetHeight;
                 // Not colliding if the vehicle is off the ground
                 if (!Prim.IsColliding)
                 {
@@ -1005,8 +1007,8 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                 //     has a decay factor. This says this force should
                 //     be computed with a motor.
                 // TODO: add interaction with banking.
-                VDetailLog("{0},  MoveLinear,limitMotorUp,distAbove={1},downForce={2}",
-                                    Prim.LocalID, distanceAboveGround, ret);
+                VDetailLog("{0},  MoveLinear,limitMotorUp,distAbove={1},colliding={2},ret={3}",
+                                    Prim.LocalID, distanceAboveGround, Prim.IsColliding, ret);
             }
             return ret;
         }
@@ -1055,7 +1057,10 @@ namespace OpenSim.Region.Physics.BulletSPlugin
             // TODO: Should this be applied as an angular force (torque)?
             if (!m_lastAngularCorrection.ApproxEquals(Vector3.Zero, 0.01f))
             {
-                Vector3 scaledCorrection = m_lastAngularCorrection * pTimestep;
+                // DEBUG DEBUG DEBUG: optionally scale the angular velocity. Debugging SL vs ODE turning functions.
+                Vector3 scaledCorrection = m_lastAngularCorrection;
+                if (PhysicsScene.VehicleScaleAngularVelocityByTimestep)
+                    scaledCorrection *= pTimestep;
                 VehicleRotationalVelocity = scaledCorrection;
 
                 VDetailLog("{0},  MoveAngular,done,nonZero,angMotorContrib={1},vertAttrContrib={2},bankContrib={3},deflectContrib={4},totalContrib={5},scaledCorr={6}",
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSLinkset.cs b/OpenSim/Region/Physics/BulletSPlugin/BSLinkset.cs
index 0df4310..777c5cb 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSLinkset.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSLinkset.cs
@@ -32,6 +32,14 @@ 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 abstract class BSLinkset
 {
     // private static string LogHeader = "[BULLETSIM LINKSET]";
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs b/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs
index 1f7c398..d2abdb4 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs
@@ -32,6 +32,31 @@ 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 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]";
@@ -44,6 +69,7 @@ public sealed class BSLinksetCompound : BSLinkset
     // 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)
         {
@@ -63,10 +89,10 @@ public sealed class BSLinksetCompound : BSLinkset
         // InternalRefresh(requestor);
     }
 
+    // Schedule a refresh to happen after all the other taint processing.
     private void InternalRefresh(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()
         {
             if (IsRoot(requestor) && HasAnyChildren)
@@ -84,12 +110,19 @@ 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();
+        }
+        else
         {
             // 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);
             ret = true;
         }
         return ret;
@@ -108,7 +141,7 @@ public sealed class BSLinksetCompound : BSLinkset
         {
             // 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.
+            // Don't force activation so setting of DISABLE_SIMULATION can stay if used.
             BulletSimAPI.Activate2(child.PhysBody.ptr, false);
             ret = true;
         }
@@ -146,6 +179,10 @@ public sealed class BSLinksetCompound : BSLinkset
 
         if (!IsRoot(child))
         {
+            // Because it is a convenient time, recompute child world position and rotation based on
+            //    its position in the linkset.
+            RecomputeChildWorldPosition(child, true);
+
             // Cause the current shape to be freed and the new one to be built.
             InternalRefresh(LinksetRoot);
             ret = true;
@@ -154,6 +191,42 @@ public sealed class BSLinksetCompound : BSLinkset
         return ret;
     }
 
+    // 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);
+        }
+    }
+
     // Companion to RemoveBodyDependencies(). If RemoveBodyDependencies() returns 'true',
     // this routine will restore the removed constraints.
     // Called at taint-time!!
@@ -192,6 +265,7 @@ 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)
@@ -226,42 +300,57 @@ public sealed class BSLinksetCompound : BSLinkset
         {
             if (!IsRoot(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;
+                // 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);
+                    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?)
+                    // 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.ptr = IntPtr.Zero;  // Don't let the create free the child's shape
+                    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, displacementPos, displacementRot);
+                    BulletSimAPI.AddChildShapeToCompoundShape2(LinksetRoot.PhysShape.ptr, newShape.ptr, lci.OffsetPos , lci.OffsetRot);
                 }
                 else
                 {
                     // 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, displacementPos, displacementRot);
+                    BulletSimAPI.AddChildShapeToCompoundShape2(LinksetRoot.PhysShape.ptr, cPrim.PhysShape.ptr, lci.OffsetPos , lci.OffsetRot);
                 }
             }
 
-            // TODO: need to phantomize the child prims left behind.
-            //     Maybe just destroy the children bodies and shapes and have them rebuild on unlink.
-            //     Selection/deselection might cause way too many build/destructions esp. for LARGE linksets.
-
             return false;   // 'false' says to move onto the next child in the list
         });
 
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSMotors.cs b/OpenSim/Region/Physics/BulletSPlugin/BSMotors.cs
index 851d508..cf0a9dc 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSMotors.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSMotors.cs
@@ -65,7 +65,7 @@ public abstract class BSMotor
 // Can all the incremental stepping be replaced with motor classes?
 
 // Motor which moves CurrentValue to TargetValue over TimeScale seconds.
-// The TargetValue is decays in TargetValueDecayTimeScale and
+// The TargetValue decays in TargetValueDecayTimeScale and
 //     the CurrentValue will be held back by FrictionTimeScale.
 // TimeScale and TargetDelayTimeScale may be 'infinite' which means go decay.
 
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSPhysObject.cs b/OpenSim/Region/Physics/BulletSPlugin/BSPhysObject.cs
index f6a890e..f3b6993 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; }
@@ -109,6 +113,13 @@ public abstract class BSPhysObject : PhysicsActor
     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; }
@@ -243,7 +265,9 @@ 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 4d203ff..35d22c0 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
@@ -108,8 +108,8 @@ public sealed class BSPrim : BSPhysObject
         _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 +143,9 @@ 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();
         });
     }
 
@@ -189,7 +191,8 @@ public sealed class BSPrim : BSPhysObject
         }
     }
     public override bool Selected {
-        set {
+        set
+        {
             if (value != _isSelected)
             {
                 _isSelected = value;
@@ -247,7 +250,8 @@ 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)
@@ -257,8 +261,11 @@ public sealed class BSPrim : BSPhysObject
         PhysicsScene.TaintedObject(inTaintTime, "BSPrim.ZeroMotion", delegate()
         {
             // DetailLog("{0},BSPrim.ZeroAngularMotion,call,rotVel={1}", LocalID, _rotationalVelocity);
-            BulletSimAPI.SetInterpolationAngularVelocity2(PhysBody.ptr, _rotationalVelocity);
-            BulletSimAPI.SetAngularVelocity2(PhysBody.ptr, _rotationalVelocity);
+            if (PhysBody.HasPhysicalBody)
+            {
+                BulletSimAPI.SetInterpolationAngularVelocity2(PhysBody.ptr, _rotationalVelocity);
+                BulletSimAPI.SetAngularVelocity2(PhysBody.ptr, _rotationalVelocity);
+            }
         });
     }
 
@@ -295,8 +302,11 @@ public sealed class BSPrim : BSPhysObject
             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);
+                if (PhysBody.HasPhysicalBody)
+                {
+                    BulletSimAPI.SetTranslation2(PhysBody.ptr, _position, _orientation);
+                    ActivateIfPhysical(false);
+                }
             });
         }
     }
@@ -322,12 +332,12 @@ public sealed class BSPrim : BSPhysObject
 
         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;
         }
 
@@ -335,10 +345,10 @@ public sealed class BSPrim : BSPhysObject
         {
             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;
             }
         }
@@ -413,7 +423,8 @@ 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);
             });
         }
     }
@@ -507,7 +518,8 @@ public sealed class BSPrim : BSPhysObject
             PhysicsScene.TaintedObject("BSPrim.setVelocity", delegate()
             {
                 // DetailLog("{0},BSPrim.SetVelocity,taint,vel={1}", LocalID, _velocity);
-                BulletSimAPI.SetLinearVelocity2(PhysBody.ptr, _velocity);
+                if (PhysBody.HasPhysicalBody)
+                    BulletSimAPI.SetLinearVelocity2(PhysBody.ptr, _velocity);
             });
         }
     }
@@ -556,9 +568,12 @@ public sealed class BSPrim : BSPhysObject
             // TODO: what does it mean if a child in a linkset changes its orientation? Rebuild the constraint?
             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);
+                }
             });
         }
     }
@@ -683,8 +698,9 @@ public sealed class BSPrim : BSPhysObject
             ZeroMotion(true);
 
             // Set various physical properties so other object interact properly
-            BulletSimAPI.SetFriction2(PhysBody.ptr, PhysicsScene.Params.defaultFriction);
-            BulletSimAPI.SetRestitution2(PhysBody.ptr, PhysicsScene.Params.defaultRestitution);
+            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);
@@ -711,9 +727,10 @@ public sealed class BSPrim : BSPhysObject
             // 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
@@ -861,7 +878,8 @@ 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);
             });
         }
     }
@@ -896,8 +914,11 @@ 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));
+            }
         }
     }
 
@@ -965,7 +986,8 @@ 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);
         });
     }
 
@@ -976,7 +998,8 @@ 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);
         });
     }
 
@@ -1012,7 +1035,8 @@ 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;
             }
         });
@@ -1026,7 +1050,8 @@ public sealed class BSPrim : BSPhysObject
         OMV.Vector3 applyImpulse = impulse;
         PhysicsScene.TaintedObject(inTaintTime, "BSPrim.ApplyTorqueImpulse", delegate()
         {
-            BulletSimAPI.ApplyTorqueImpulse2(PhysBody.ptr, applyImpulse);
+            if (PhysBody.HasPhysicalBody)
+                BulletSimAPI.ApplyTorqueImpulse2(PhysBody.ptr, applyImpulse);
         });
     }
 
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs b/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
index f72bd74..f4f2801 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
@@ -188,6 +188,8 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
     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; }
+    public bool VehicleScaleAngularVelocityByTimestep { get; private set; }
 
     #region Construction and Initialization
     public BSScene(string identifier)
@@ -297,6 +299,7 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
                 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);
@@ -501,7 +504,7 @@ 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,
@@ -510,7 +513,7 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
             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
+            if (VehiclePhysicalLoggingEnabled) DumpVehicles();  // DEBUG
         }
         catch (Exception e)
         {
@@ -1226,6 +1229,11 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
             (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("VehicleScaleAngularVelocityByTimestep", "If true, scale angular turning by timestep",
+            ConfigurationParameters.numericFalse,
+            (s,cf,p,v) => { s.VehicleScaleAngularVelocityByTimestep = cf.GetBoolean(p, s.BoolNumeric(v)); },
+            (s) => { return s.NumericBool(s.VehicleScaleAngularVelocityByTimestep); },
+            (s,p,l,v) => { s.VehicleScaleAngularVelocityByTimestep = s.BoolNumeric(v); } ),
 
             new ParameterDefn("MaxPersistantManifoldPoolSize", "Number of manifolds pooled (0 means default of 4096)",
             0f,
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSShapeCollection.cs b/OpenSim/Region/Physics/BulletSPlugin/BSShapeCollection.cs
index 933f573..4ab9a99 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSShapeCollection.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSShapeCollection.cs
@@ -149,7 +149,7 @@ 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)
@@ -243,12 +243,12 @@ 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)
                 {
@@ -440,7 +440,7 @@ 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;
@@ -573,7 +573,7 @@ public sealed class BSShapeCollection : IDisposable
             // Native shapes are scaled in Bullet so set the scaling to the size
             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);
@@ -590,7 +590,7 @@ 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);
@@ -793,7 +793,7 @@ 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.
@@ -860,7 +860,7 @@ 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
@@ -919,7 +919,7 @@ 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.
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSTerrainHeightmap.cs b/OpenSim/Region/Physics/BulletSPlugin/BSTerrainHeightmap.cs
index 83b9c37..2d379bb 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSTerrainHeightmap.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSTerrainHeightmap.cs
@@ -136,7 +136,7 @@ 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.
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSTerrainManager.cs b/OpenSim/Region/Physics/BulletSPlugin/BSTerrainManager.cs
index 83df360..c28d69d 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSTerrainManager.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSTerrainManager.cs
@@ -151,13 +151,13 @@ 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();
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSTerrainMesh.cs b/OpenSim/Region/Physics/BulletSPlugin/BSTerrainMesh.cs
index 6ce767d..3473006 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSTerrainMesh.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSTerrainMesh.cs
@@ -94,7 +94,7 @@ public sealed class BSTerrainMesh : BSTerrainPhys
         m_terrainShape = new BulletShape(BulletSimAPI.CreateMeshShape2(PhysicsScene.World.ptr,
                                                     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);
@@ -107,7 +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);
@@ -140,7 +140,7 @@ 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.
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BulletSimAPI.cs b/OpenSim/Region/Physics/BulletSPlugin/BulletSimAPI.cs
index 2671995..1559025 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BulletSimAPI.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BulletSimAPI.cs
@@ -53,6 +53,9 @@ public struct BulletSim
 // An allocated Bullet btRigidBody
 public struct BulletBody
 {
+    public BulletBody(uint id) : this(id, IntPtr.Zero)
+    {
+    }
     public BulletBody(uint id, IntPtr xx)
     {
         ID = id;
@@ -64,6 +67,13 @@ public struct BulletBody
     public uint ID;
     public CollisionFilterGroups collisionGroup;
     public CollisionFilterGroups collisionMask;
+
+    public void Clear()
+    {
+        ptr = IntPtr.Zero;
+    }
+    public bool HasPhysicalBody { get { return ptr != IntPtr.Zero; } }
+
     public override string ToString()
     {
         StringBuilder buff = new StringBuilder();
@@ -103,6 +113,13 @@ public struct BulletShape
     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();
@@ -140,6 +157,12 @@ public struct BulletConstraint
         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.
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt b/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
index a2161c3..1c7b577 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
+++ b/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
@@ -11,12 +11,14 @@ CRASHES
 
 VEHICLES TODO LIST:
 =================================================
-Neb car jiggling left and right
-        Happens on terrain and any other mesh object. Flat cubes are much smoother.
+Neb vehicle taking > 25ms of physics time!!
 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.
+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.
 For limitMotorUp, use raycast down to find if vehicle is in the air.
 Implement function efficiency for lineaar and angular motion.
 Should vehicle angular/linear movement friction happen after all the components
@@ -30,6 +32,9 @@ Border crossing with linked vehicle causes crash
 
 BULLETSIM TODO LIST:
 =================================================
+Avatar height off after unsitting (float off ground)
+        Editting appearance then moving restores.
+        Must not be initializing height when recreating capsule after unsit.
 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.
 Disable activity of passive linkset children.
@@ -38,7 +43,8 @@ Disable activity of passive linkset children.
 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?
-Single prim vehicles don't seem to properly vehiclize.
+Linksets should allow collisions to individual children
+        Add LocalID to children shapes in LinksetCompound and create events for individuals
 Gun sending shooter flying.
 Collision margin (gap between physical objects lying on each other)
 Boundry checking (crashes related to crossing boundry)
@@ -145,4 +151,6 @@ Linkset implementation using compound shapes. (Resolution: implemented LinksetCo
 Light cycle falling over when driving (Resolution: implemented VerticalAttractor)
 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)
\ No newline at end of file
+        (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)