BulletSim: Parameters settable from ini file. Linksets. Physical property value tuning

8 files changed, 358 insertions, 213 deletions

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs b/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
index 82361ad..9f9ebcc 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
@@ -51,8 +51,6 @@ public class BSCharacter : PhysicsActor
     private Vector3 _position;
     private float _mass = 80f;
     public float _density = 60f;
-    public float CAPSULE_RADIUS = 0.37f;
-    public float CAPSULE_LENGTH = 2.140599f;
     private Vector3 _force;
     private Vector3 _velocity;
     private Vector3 _torque;
@@ -96,7 +94,8 @@ public class BSCharacter : PhysicsActor
         _velocity = Vector3.Zero;
         _buoyancy = 0f; // characters return a buoyancy of zero
         _scale = new Vector3(1f, 1f, 1f);
-        float AVvolume = (float) (Math.PI*Math.Pow(CAPSULE_RADIUS, 2)*CAPSULE_LENGTH);
+        float AVvolume = (float) (Math.PI*Math.Pow(_scene.Params.avatarCapsuleRadius, 2)*_scene.Params.avatarCapsuleHeight);
+        _density = _scene.Params.avatarDensity;
         _mass = _density*AVvolume;
 
         ShapeData shapeData = new ShapeData();
@@ -109,6 +108,8 @@ public class BSCharacter : PhysicsActor
         shapeData.Mass = _mass;
         shapeData.Buoyancy = isFlying ? 1f : 0f;
         shapeData.Static = ShapeData.numericFalse;
+        shapeData.Friction = _scene.Params.avatarFriction;
+        shapeData.Restitution = _scene.Params.defaultRestitution;
 
         // do actual create at taint time
         _scene.TaintedObject(delegate()
@@ -395,9 +396,9 @@ public class BSCharacter : PhysicsActor
             _acceleration = entprop.Acceleration;
             changed = true;
         }
-        if (_rotationalVelocity != entprop.AngularVelocity)
+        if (_rotationalVelocity != entprop.RotationalVelocity)
         {
-            _rotationalVelocity = entprop.AngularVelocity;
+            _rotationalVelocity = entprop.RotationalVelocity;
             changed = true;
         }
         if (changed)
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
index f2ab2d9..04cb452 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
@@ -71,6 +71,7 @@ public sealed class BSPrim : PhysicsActor
     private bool _isPhysical;
     private bool _flying;
     private float _friction;
+    private float _restitution;
     private bool _setAlwaysRun;
     private bool _throttleUpdates;
     private bool _isColliding;
@@ -101,7 +102,7 @@ public sealed class BSPrim : PhysicsActor
     private float _PIDHoverTao;
 
     public BSPrim(uint localID, String primName, BSScene parent_scene, OMV.Vector3 pos, OMV.Vector3 size,
-                       OMV.Quaternion rotation, IMesh mesh, PrimitiveBaseShape pbs, bool pisPhysical)
+                       OMV.Quaternion rotation, PrimitiveBaseShape pbs, bool pisPhysical)
     {
         // m_log.DebugFormat("{0}: BSPrim creation of {1}, id={2}", LogHeader, primName, localID);
         _localID = localID;
@@ -113,15 +114,16 @@ public sealed class BSPrim : PhysicsActor
         _orientation = rotation;
         _buoyancy = 1f;
         _velocity = OMV.Vector3.Zero;
+        _rotationalVelocity = OMV.Vector3.Zero;
         _angularVelocity = OMV.Vector3.Zero;
-        _mesh = mesh;
         _hullKey = 0;
         _pbs = pbs;
         _isPhysical = pisPhysical;
         _isVolumeDetect = false;
         _subscribedEventsMs = 0;
-        _friction = _scene.DefaultFriction; // TODO: compute based on object material
-        _density = _scene.DefaultDensity; // TODO: compute based on object material
+        _friction = _scene.Params.defaultFriction; // TODO: compute based on object material
+        _density = _scene.Params.defaultDensity; // TODO: compute based on object material
+        _restitution = _scene.Params.defaultRestitution;
         _parentPrim = null;     // not a child or a parent
         _vehicle = new BSDynamics(this);    // add vehicleness
         _childrenPrims = new List<BSPrim>();
@@ -132,8 +134,7 @@ public sealed class BSPrim : PhysicsActor
         // do the actual object creation at taint time
         _scene.TaintedObject(delegate()
         {
-            CreateGeom();
-            CreateObject();
+            RecreateGeomAndObject();
         });
     }
 
@@ -239,6 +240,7 @@ public sealed class BSPrim : PhysicsActor
         return; 
     }
 
+    // I am the root of a linkset and a new child is being added
     public void AddChildToLinkset(BSPrim pchild)
     {
         BSPrim child = pchild;
@@ -254,6 +256,8 @@ public sealed class BSPrim : PhysicsActor
         return;
     }
 
+    // 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.
     public void RemoveChildFromLinkset(BSPrim pchild)
     {
         BSPrim child = pchild;
@@ -290,6 +294,17 @@ public sealed class BSPrim : PhysicsActor
         get { return (_parentPrim == null && _childrenPrims.Count != 0); }
     }
 
+    // Set motion values to zero.
+    // Do it to the properties so the values get set in the physics engine.
+    // Push the setting of the values to the viewer.
+    private void ZeroMotion()
+    {
+        Velocity = OMV.Vector3.Zero;
+        _acceleration = OMV.Vector3.Zero;
+        RotationalVelocity = OMV.Vector3.Zero;
+        base.RequestPhysicsterseUpdate();
+    }
+
     public override void LockAngularMotion(OMV.Vector3 axis) { return; }
 
     public override OMV.Vector3 Position { 
@@ -390,18 +405,6 @@ public sealed class BSPrim : PhysicsActor
             });
         } 
     }
-    public OMV.Vector3 AngularVelocity
-    {
-        get { return _angularVelocity; }
-        set
-        {
-            _angularVelocity = value;
-            _scene.TaintedObject(delegate()
-            {
-                BulletSimAPI.SetObjectAngularVelocity(_scene.WorldID, LocalID, _angularVelocity);
-            });
-        }
-    }
     public override OMV.Vector3 Torque { 
         get { return _torque; } 
         set { _torque = value; 
@@ -419,11 +422,11 @@ public sealed class BSPrim : PhysicsActor
         get { return _orientation; } 
         set {
             _orientation = value;
+            // m_log.DebugFormat("{0}: set orientation: id={1}, ori={2}", LogHeader, LocalID, _orientation);
             _scene.TaintedObject(delegate()
             {
                 // _position = BulletSimAPI.GetObjectPosition(_scene.WorldID, _localID);
                 BulletSimAPI.SetObjectTranslation(_scene.WorldID, _localID, _position, _orientation);
-                // m_log.DebugFormat("{0}: set orientation: {1}", LogHeader, _orientation);
             });
         } 
     }
@@ -505,8 +508,16 @@ public sealed class BSPrim : PhysicsActor
         get { return _rotationalVelocity; } 
         set { _rotationalVelocity = value; 
             // m_log.DebugFormat("{0}: RotationalVelocity={1}", LogHeader, _rotationalVelocity);
+            _scene.TaintedObject(delegate()
+            {
+                BulletSimAPI.SetObjectAngularVelocity(_scene.WorldID, LocalID, _rotationalVelocity);
+            });
         } 
     }
+    public OMV.Vector3 AngularVelocity { 
+        get { return _angularVelocity; } 
+        set { _angularVelocity = value; } 
+    }
     public override bool Kinematic { 
         get { return _kinematic; } 
         set { _kinematic = value; 
@@ -866,9 +877,6 @@ public sealed class BSPrim : PhysicsActor
 
         returnMass = _density * volume;
 
-        if (returnMass <= 0)
-            returnMass = 0.0001f;//ckrinke: Mass must be greater then zero.
-
         if (IsRootOfLinkset)
         {
             foreach (BSPrim prim in _childrenPrims)
@@ -877,8 +885,12 @@ public sealed class BSPrim : PhysicsActor
             }
         }
 
-        if (returnMass > _scene.maximumMassObject)
-            returnMass = _scene.maximumMassObject;
+        if (returnMass <= 0)
+            returnMass = 0.0001f;
+
+        if (returnMass > _scene.MaximumObjectMass)
+            returnMass = _scene.MaximumObjectMass;
+
         return returnMass;
     }// end CalculateMass
     #endregion Mass Calculation
@@ -887,6 +899,15 @@ public sealed class BSPrim : PhysicsActor
     // No locking here because this is done when we know physics is not simulating
     private void CreateGeom()
     {
+        // Since we're recreating new, get rid of any previously generated shape
+        if (_hullKey != 0)
+        {
+            // m_log.DebugFormat("{0}: CreateGeom: deleting old hull. Key={1}", LogHeader, _hullKey);
+            BulletSimAPI.DestroyHull(_scene.WorldID, _hullKey);
+            _hullKey = 0;
+            _hulls.Clear();
+        }
+
         if (_mesh == null)
         {
             // the mesher thought this was too simple to mesh. Use a native Bullet collision shape.
@@ -902,21 +923,13 @@ public sealed class BSPrim : PhysicsActor
             }
             else
             {
-                // m_log.DebugFormat("{0}: CreateGeom: mesh null. Defaulting to box of size {1}", LogHeader, _size);
+                // m_log.DebugFormat("{0}: CreateGeom: mesh null. Defaulting to box. lid={1}, size={2}", LogHeader, LocalID,  _size);
                 _shapeType = ShapeData.PhysicsShapeType.SHAPE_BOX;
                 _scale = _size;
             }
         }
         else
         {
-            if (_hullKey != 0)
-            {
-                // m_log.DebugFormat("{0}: CreateGeom: deleting old hull. Key={1}", LogHeader, _hullKey);
-                BulletSimAPI.DestroyHull(_scene.WorldID, _hullKey);
-                _hullKey = 0;
-                _hulls.Clear();
-            }
-
             int[] indices = _mesh.getIndexListAsInt();
             List<OMV.Vector3> vertices = _mesh.getVertexList();
 
@@ -997,7 +1010,7 @@ public sealed class BSPrim : PhysicsActor
 
             // create the hull definition in Bullet
             _hullKey = (ulong)_pbs.GetHashCode();
-            // m_log.DebugFormat("{0}: CreateGeom: calling CreateHull. lid= {1}, key={2}, hulls={3}", LogHeader, _localID, _hullKey, hullCount);
+            // m_log.DebugFormat("{0}: CreateGeom: calling CreateHull. lid={1}, key={2}, hulls={3}", LogHeader, _localID, _hullKey, hullCount);
             BulletSimAPI.CreateHull(_scene.WorldID, _hullKey, hullCount, convHulls);
             _shapeType = ShapeData.PhysicsShapeType.SHAPE_HULL;
             // meshes are already scaled by the meshmerizer
@@ -1006,6 +1019,8 @@ public sealed class BSPrim : PhysicsActor
         return;
     }
 
+    // Callback from convex hull creater with a newly created hull.
+    // Just add it to the collection of hulls for this shape.
     private void HullReturn(ConvexResult result)
     {
         _hulls.Add(result);
@@ -1019,13 +1034,12 @@ public sealed class BSPrim : PhysicsActor
         if (IsRootOfLinkset)
         {
             // Create a linkset around this object
-            CreateLinksetWithCompoundHull();
-            // CreateLinksetWithConstraints();
+            // CreateLinksetWithCompoundHull();
+            CreateLinksetWithConstraints();
         }
         else
         {
             // simple object
-            // m_log.DebugFormat("{0}: CreateObject. ID={1}", LogHeader, LocalID);
             ShapeData shape;
             FillShapeInfo(out shape);
             BulletSimAPI.CreateObject(_scene.WorldID, shape);
@@ -1034,6 +1048,7 @@ public sealed class BSPrim : PhysicsActor
 
     // Create a linkset by creating a compound hull at the root prim that consists of all
     // the children.
+    // NOTE: This does not allow proper collisions with the children prims so it is not a workable solution
     void CreateLinksetWithCompoundHull()
     {
         // If I am the root prim of a linkset, replace my physical shape with all the
@@ -1055,8 +1070,27 @@ public sealed class BSPrim : PhysicsActor
         BulletSimAPI.CreateLinkset(_scene.WorldID, totalPrimsInLinkset, shapes);
     }
 
+    // Copy prim's info into the BulletSim shape description structure
+    public void FillShapeInfo(out ShapeData shape)
+    {
+        shape.ID = _localID;
+        shape.Type = _shapeType;
+        shape.Position = _position;
+        shape.Rotation = _orientation;
+        shape.Velocity = _velocity;
+        shape.Scale = _scale;
+        shape.Mass = _isPhysical ? _mass : 0f;
+        shape.Buoyancy = _buoyancy;
+        shape.MeshKey = _hullKey;
+        shape.Friction = _friction;
+        shape.Restitution = _restitution;
+        shape.Collidable = (!IsPhantom) ? ShapeData.numericTrue : ShapeData.numericFalse;
+        shape.Static = _isPhysical ? ShapeData.numericFalse : ShapeData.numericTrue;
+    }
+
     // Create the linkset by putting constraints between the objects of the set so they cannot move
     // relative to each other.
+    // TODO: make this more effeicient: a large linkset gets rebuilt over and over and prims are added
     void CreateLinksetWithConstraints()
     {
         // m_log.DebugFormat("{0}: CreateLinkset. Root prim={1}, prims={2}", LogHeader, LocalID, _childrenPrims.Count+1);
@@ -1070,76 +1104,48 @@ public sealed class BSPrim : PhysicsActor
         // create constraints between the root prim and each of the children
         foreach (BSPrim prim in _childrenPrims)
         {
-            // this is a constraint that allows no freedom of movement between the two objects
-            // http://bulletphysics.org/Bullet/phpBB3/viewtopic.php?t=4818
             // m_log.DebugFormat("{0}: CreateObject: AddConstraint between root prim {1} and child prim {2}", LogHeader, LocalID, prim.LocalID);
 
+            // Zero motion for children so they don't interpolate
+            prim.ZeroMotion();
+
             // relative position normalized to the root prim
             OMV.Vector3 childRelativePosition = (prim._position - this._position) * OMV.Quaternion.Inverse(this._orientation);
-            // OMV.Quaternion relativeRotation = OMV.Quaternion.Identity;
 
-            // rotation is pointing up the vector between the object centers
-            OMV.Quaternion relativeRotation = OMV.Quaternion.CreateFromAxisAngle(childRelativePosition, 0f);
-
-            /* // the logic for relative rotation from http://bulletphysics.org/Bullet/phpBB3/viewtopic.php?t=6391
-            OMV.Vector3 rrn = childRelativePosition;
-            rrn.Normalize();
-            rrn /= rrn.X;
-            OMV.Matrix4 rotmat = new OMV.Matrix4(rrn.X, rrn.Y, rrn.Z, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1);
-            OMV.Quaternion relativeRotation = OMV.Quaternion.CreateFromRotationMatrix(rotmat);
-             */
+            // relative rotation of the child to the parent
+            OMV.Quaternion relativeRotation = OMV.Quaternion.Inverse(prim._orientation) * this._orientation;
 
+            // this is a constraint that allows no freedom of movement between the two objects
+            // http://bulletphysics.org/Bullet/phpBB3/viewtopic.php?t=4818
             BulletSimAPI.AddConstraint(_scene.WorldID, LocalID, prim.LocalID, 
-                childRelativePosition / 2,
-                relativeRotation,
-                -childRelativePosition / 2,
+                childRelativePosition,
                 relativeRotation,
+                OMV.Vector3.Zero,
+                OMV.Quaternion.Identity,
                 OMV.Vector3.Zero, OMV.Vector3.Zero,
                 OMV.Vector3.Zero, OMV.Vector3.Zero);
         }
     }
 
-    // Copy prim's info into the BulletSim shape description structure
-    public void FillShapeInfo(out ShapeData shape)
-    {
-        shape.ID = _localID;
-        shape.Type = _shapeType;
-        shape.Position = _position;
-        shape.Rotation = _orientation;
-        shape.Velocity = _velocity;
-        shape.Scale = _scale;
-        shape.Mass = _isPhysical ? _mass : 0f;
-        shape.Buoyancy = _buoyancy;
-        shape.MeshKey = _hullKey;
-        shape.Collidable = (!IsPhantom) ? ShapeData.numericTrue : ShapeData.numericFalse;
-        shape.Friction = _friction;
-        shape.Static = _isPhysical ? ShapeData.numericFalse : ShapeData.numericTrue;
-    }
-
     // Rebuild the geometry and object.
     // This is called when the shape changes so we need to recreate the mesh/hull.
     // No locking here because this is done when the physics engine is not simulating
     private void RecreateGeomAndObject()
     {
-        if (_hullKey != 0)
-        {
-            // if a hull already exists, delete the old one
-            BulletSimAPI.DestroyHull(_scene.WorldID, _hullKey);
-            _hullKey = 0;
-        }
         // If this object is complex or we are the root of a linkset, build a mesh.
         // The root of a linkset must be a mesh so we can create the linked compound object.
-        if (_scene.NeedsMeshing(_pbs) || IsRootOfLinkset )
+        // if (_scene.NeedsMeshing(_pbs) || IsRootOfLinkset )
+        if (_scene.NeedsMeshing(_pbs))  // linksets with constraints don't need a root mesh
         {
             // m_log.DebugFormat("{0}: RecreateGeomAndObject: creating mesh", LogHeader);
-            _mesh = _scene.mesher.CreateMesh(_avName, _pbs, _size, _scene.meshLOD, _isPhysical);
+            _mesh = _scene.mesher.CreateMesh(_avName, _pbs, _size, _scene.MeshLOD, _isPhysical);
         }
         else
         {
-            // it's a BulletSim native shape.
+            // implement the shape with a Bullet native shape.
             _mesh = null;
         }
-        CreateGeom();   // create the geometry for this prim
+        CreateGeom();
         CreateObject();
         return;
     }
@@ -1152,48 +1158,82 @@ public sealed class BSPrim : PhysicsActor
         Rotation      = 1 << 1,
         Velocity      = 1 << 2,
         Acceleration  = 1 << 3,
-        AngularVel    = 1 << 4
+        RotationalVel = 1 << 4
     }
 
+    const float ROTATION_TOLERANCE = 0.01f;
+    const float VELOCITY_TOLERANCE = 0.001f;
+    const float POSITION_TOLERANCE = 0.05f;
+    const float ACCELERATION_TOLERANCE = 0.01f;
+    const float ROTATIONAL_VELOCITY_TOLERANCE = 0.01f;
+    const bool SHOULD_DAMP_UPDATES = false;
+
     public void UpdateProperties(EntityProperties entprop)
     {
         UpdatedProperties changed = 0;
-        // assign to the local variables so the normal set action does not happen
-        if (_position != entprop.Position)
-        {
-            _position = entprop.Position;
-            // m_log.DebugFormat("{0}: UpdateProperties: position = {1}", LogHeader, _position);
-            changed |= UpdatedProperties.Position;
-        }
-        if (_orientation != entprop.Rotation)
-        {
-            _orientation = entprop.Rotation;
-            // m_log.DebugFormat("{0}: UpdateProperties: rotation = {1}", LogHeader, _orientation);
-            changed |= UpdatedProperties.Rotation;
-        }
-        if (_velocity != entprop.Velocity)
-        {
-            _velocity = entprop.Velocity;
-            // m_log.DebugFormat("{0}: UpdateProperties: velocity = {1}", LogHeader, _velocity);
-            changed |= UpdatedProperties.Velocity;
-        }
-        if (_acceleration != entprop.Acceleration)
-        {
-            _acceleration = entprop.Acceleration;
-            // m_log.DebugFormat("{0}: UpdateProperties: acceleration = {1}", LogHeader, _acceleration);
-            changed |= UpdatedProperties.Acceleration;
-        }
-        if (_rotationalVelocity != entprop.AngularVelocity)
+        if (SHOULD_DAMP_UPDATES)
         {
-            _rotationalVelocity = entprop.AngularVelocity;
-            // m_log.DebugFormat("{0}: UpdateProperties: rotationalVelocity = {1}", LogHeader, _rotationalVelocity);
-            changed |= UpdatedProperties.AngularVel;
+            // 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;
+                // m_log.DebugFormat("{0}: UpdateProperties: id={1}, pos = {2}", LogHeader, LocalID, _position);
+                changed |= UpdatedProperties.Position;
+            }
+            // if (_orientation != entprop.Rotation)
+            if (!_orientation.ApproxEquals(entprop.Rotation, ROTATION_TOLERANCE))
+            {
+                _orientation = entprop.Rotation;
+                // m_log.DebugFormat("{0}: UpdateProperties: id={1}, rot = {2}", LogHeader, LocalID, _orientation);
+                changed |= UpdatedProperties.Rotation;
+            }
+            // if (_velocity != entprop.Velocity)
+            if (!_velocity.ApproxEquals(entprop.Velocity, VELOCITY_TOLERANCE))
+            {
+                _velocity = entprop.Velocity;
+                // m_log.DebugFormat("{0}: UpdateProperties: velocity = {1}", LogHeader, _velocity);
+                changed |= UpdatedProperties.Velocity;
+            }
+            // if (_acceleration != entprop.Acceleration)
+            if (!_acceleration.ApproxEquals(entprop.Acceleration, ACCELERATION_TOLERANCE))
+            {
+                _acceleration = entprop.Acceleration;
+                // m_log.DebugFormat("{0}: UpdateProperties: acceleration = {1}", LogHeader, _acceleration);
+                changed |= UpdatedProperties.Acceleration;
+            }
+            // if (_rotationalVelocity != entprop.RotationalVelocity)
+            if (!_rotationalVelocity.ApproxEquals(entprop.RotationalVelocity, ROTATIONAL_VELOCITY_TOLERANCE))
+            {
+                _rotationalVelocity = entprop.RotationalVelocity;
+                // m_log.DebugFormat("{0}: UpdateProperties: rotationalVelocity = {1}", LogHeader, _rotationalVelocity);
+                changed |= UpdatedProperties.RotationalVel;
+            }
+            if (changed != 0)
+            {
+                // m_log.DebugFormat("{0}: UpdateProperties: id={1}, c={2}, pos={3}, rot={4}", LogHeader, LocalID, changed, _position, _orientation);
+                // Only update the position of single objects and linkset roots
+                if (this._parentPrim == null)
+                {
+                    // m_log.DebugFormat("{0}: RequestTerseUpdate. id={1}, ch={2}, pos={3}, rot={4}", LogHeader, LocalID, changed, _position, _orientation);
+                    base.RequestPhysicsterseUpdate();
+                }
+            }
         }
-        if (changed != 0)
+        else
         {
-            // m_log.DebugFormat("{0}: UpdateProperties: id={1}, c={2}, pos={3}, rot={4}", LogHeader, LocalID, changed, _position, _orientation);
+            // Don't check for damping here -- it's done in BulletSim and SceneObjectPart.
             if (this._parentPrim == null)
+            {
+                // Assign to the local variables so the normal set action does not happen
+                _position = entprop.Position;
+                _orientation = entprop.Rotation;
+                _velocity = entprop.Velocity;
+                _acceleration = entprop.Acceleration;
+                _rotationalVelocity = entprop.RotationalVelocity;
+                // m_log.DebugFormat("{0}: RequestTerseUpdate. id={1}, ch={2}, pos={3}, rot={4}", LogHeader, LocalID, changed, _position, _orientation);
                 base.RequestPhysicsterseUpdate();
+            }
         }
     }
 
@@ -1201,7 +1241,8 @@ public sealed class BSPrim : PhysicsActor
     public void Collide(uint collidingWith, ActorTypes type, OMV.Vector3 contactPoint, OMV.Vector3 contactNormal, float pentrationDepth)
     {
         // m_log.DebugFormat("{0}: Collide: ms={1}, id={2}, with={3}", LogHeader, _subscribedEventsMs, LocalID, collidingWith);
-        // The following makes IsColliding() and IsCollidingGround() work
+
+        // The following lines make IsColliding() and IsCollidingGround() work
         _collidingStep = _scene.SimulationStep;
         if (collidingWith == BSScene.TERRAIN_ID || collidingWith == BSScene.GROUNDPLANE_ID)
         {
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs b/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
index 7c11f2b..de86d59 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
@@ -71,11 +71,17 @@ public class BSScene : PhysicsScene
     private uint m_worldID;
     public uint WorldID { get { return m_worldID; } }
 
+    private bool m_initialized = false;
+
     public IMesher mesher;
-    public int meshLOD = 32;
+    private int m_meshLOD;
+    public int MeshLOD
+    {
+        get { return m_meshLOD; }
+    }
 
-    private int m_maxSubSteps = 10;
-    private float m_fixedTimeStep = 1f / 60f;
+    private int m_maxSubSteps;
+    private float m_fixedTimeStep;
     private long m_simulationStep = 0;
     public long SimulationStep { get { return m_simulationStep; } }
 
@@ -84,68 +90,65 @@ public class BSScene : PhysicsScene
     private int m_simulationNowTime;
     public int SimulationNowTime { get { return m_simulationNowTime; } }
 
-    private int m_maxCollisionsPerFrame = 2048;
+    private int m_maxCollisionsPerFrame;
     private CollisionDesc[] m_collisionArray;
     private GCHandle m_collisionArrayPinnedHandle;
 
-    private int m_maxUpdatesPerFrame = 2048;
+    private int m_maxUpdatesPerFrame;
     private EntityProperties[] m_updateArray;
     private GCHandle m_updateArrayPinnedHandle;
 
     private bool _meshSculptedPrim = true;         // cause scuplted prims to get meshed
     private bool _forceSimplePrimMeshing = false;   // if a cube or sphere, let Bullet do internal shapes
-    public float maximumMassObject = 10000.01f;
 
-    public const uint TERRAIN_ID = 0;
+    public const uint TERRAIN_ID = 0;       // OpenSim senses terrain with a localID of zero
     public const uint GROUNDPLANE_ID = 1;
 
-    public float DefaultFriction = 0.70f;
-    public float DefaultDensity = 10.000006836f; // Aluminum g/cm3;  TODO: compute based on object material
-    public Vector3 DefaultGravity = new Vector3(0, 0, -9.80665f);
+    public ConfigurationParameters Params
+    {
+        get { return m_params[0]; }
+    }
+    public Vector3 DefaultGravity
+    {
+        get { return new Vector3(0f, 0f, Params.gravity); }
+    }
+
+    private float m_maximumObjectMass;
+    public float MaximumObjectMass
+    {
+        get { return m_maximumObjectMass; }
+    }
 
     public delegate void TaintCallback();
     private List<TaintCallback> _taintedObjects;
     private Object _taintLock = new Object();
 
     // A pointer to an instance if this structure is passed to the C++ code
-    // Format of this structure must match the definition in the C++ code
-    private struct ConfigurationParameters
-    {
-        public float defaultFriction;
-        public float defaultDensity;
-        public float collisionMargin;
-        public float gravity;
-
-        public float linearDamping;
-        public float angularDamping;
-        public float deactivationTime;
-        public float linearSleepingThreshold;
-        public float angularSleepingThreshold;
-
-        public float terrainFriction;
-        public float terrainHitFriction;
-        public float terrainRestitution;
-        public float avatarFriction;
-        public float avatarCapsuleRadius;
-        public float avatarCapsuleHeight;
-    }
-    ConfigurationParameters m_params;
+    ConfigurationParameters[] m_params;
     GCHandle m_paramsHandle;
 
     private BulletSimAPI.DebugLogCallback debugLogCallbackHandle;
 
     public BSScene(string identifier)
     {
+        m_initialized = false;
     }
 
     public override void Initialise(IMesher meshmerizer, IConfigSource config)
     {
-        m_params = new ConfigurationParameters();
+        // Allocate pinned memory to pass parameters.
+        m_params = new ConfigurationParameters[1];
         m_paramsHandle = GCHandle.Alloc(m_params, GCHandleType.Pinned);
 
         // Set default values for physics parameters plus any overrides from the ini file
         GetInitialParameterValues(config);
 
+        // allocate more pinned memory close to the above in an attempt to get the memory all together
+        m_collisionArray = new CollisionDesc[m_maxCollisionsPerFrame];
+        m_collisionArrayPinnedHandle = GCHandle.Alloc(m_collisionArray, GCHandleType.Pinned);
+        m_updateArray = new EntityProperties[m_maxUpdatesPerFrame];
+        m_updateArrayPinnedHandle = GCHandle.Alloc(m_updateArray, GCHandleType.Pinned);
+
         // if Debug, enable logging from the unmanaged code
         if (m_log.IsDebugEnabled)
         {
@@ -160,68 +163,95 @@ public class BSScene : PhysicsScene
         // The bounding box for the simulated world
         Vector3 worldExtent = new Vector3(Constants.RegionSize, Constants.RegionSize, 4096f);
 
-        // Allocate pinned memory to pass back object property updates and collisions from simulation step
-        m_collisionArray = new CollisionDesc[m_maxCollisionsPerFrame];
-        m_collisionArrayPinnedHandle = GCHandle.Alloc(m_collisionArray, GCHandleType.Pinned);
-        m_updateArray = new EntityProperties[m_maxUpdatesPerFrame];
-        m_updateArrayPinnedHandle = GCHandle.Alloc(m_updateArray, GCHandleType.Pinned);
-
         // m_log.DebugFormat("{0}: Initialize: Calling BulletSimAPI.Initialize.", LogHeader);
-        m_worldID = BulletSimAPI.Initialize(worldExtent, 
+        m_worldID = BulletSimAPI.Initialize(worldExtent, m_paramsHandle.AddrOfPinnedObject(),
                                         m_maxCollisionsPerFrame, m_collisionArrayPinnedHandle.AddrOfPinnedObject(),
                                         m_maxUpdatesPerFrame, m_updateArrayPinnedHandle.AddrOfPinnedObject());
+
+        m_initialized = true;
     }
 
+    // All default parameter values are set here. There should be no values set in the
+    // variable definitions.
     private void GetInitialParameterValues(IConfigSource config)
     {
+        ConfigurationParameters parms = new ConfigurationParameters();
+
         _meshSculptedPrim = true;           // mesh sculpted prims
         _forceSimplePrimMeshing = false;    // use complex meshing if called for
 
-        // Set the default values for the physics parameters
-        m_params.defaultFriction = 0.70f;
-        m_params.defaultDensity = 10.000006836f; // Aluminum g/cm3
-        m_params.collisionMargin = 0.0f;
-        m_params.gravity = -9.80665f;
-
-        m_params.linearDamping = 0.1f;
-        m_params.angularDamping = 0.85f;
-        m_params.deactivationTime = 0.2f;
-        m_params.linearSleepingThreshold = 0.8f;
-        m_params.angularSleepingThreshold = 1.0f;
-
-        m_params.terrainFriction = 0.85f;
-        m_params.terrainHitFriction = 0.8f;
-        m_params.terrainRestitution = 0.2f;
-        m_params.avatarFriction = 0.85f;
-        m_params.avatarCapsuleRadius = 0.37f;
-        m_params.avatarCapsuleHeight = 1.5f; // 2.140599f
+        m_meshLOD = 32;
+
+        m_maxSubSteps = 10;
+        m_fixedTimeStep = 1f / 60f;
+        m_maxCollisionsPerFrame = 2048;
+        m_maxUpdatesPerFrame = 2048;
+        m_maximumObjectMass = 10000.01f;
+
+        parms.defaultFriction = 0.70f;
+        parms.defaultDensity = 10.000006836f; // Aluminum g/cm3
+        parms.defaultRestitution = 0f;
+        parms.collisionMargin = 0.0f;
+        parms.gravity = -9.80665f;
+
+        parms.linearDamping = 0.0f;
+        parms.angularDamping = 0.0f;
+        parms.deactivationTime = 0.2f;
+        parms.linearSleepingThreshold = 0.8f;
+        parms.angularSleepingThreshold = 1.0f;
+        parms.ccdMotionThreshold = 0.5f;    // set to zero to disable
+        parms.ccdSweptSphereRadius = 0.2f;
+
+        parms.terrainFriction = 0.85f;
+        parms.terrainHitFriction = 0.8f;
+        parms.terrainRestitution = 0.2f;
+        parms.avatarFriction = 0.85f;
+        parms.avatarDensity = 60f;
+        parms.avatarCapsuleRadius = 0.37f;
+        parms.avatarCapsuleHeight = 1.5f; // 2.140599f
 
         if (config != null)
         {
             // If there are specifications in the ini file, use those values
+            // WHEN ADDING OR UPDATING THIS SECTION, BE SURE TO ALSO UPDATE OpenSimDefaults.ini
             IConfig pConfig = config.Configs["BulletSim"];
             if (pConfig != null)
             {
-                _meshSculptedPrim = pConfig.GetBoolean("MeshSculptedPrim", true);
-                _forceSimplePrimMeshing = pConfig.GetBoolean("ForceSimplePrimMeshing", false);
-
-                m_params.defaultFriction = pConfig.GetFloat("DefaultFriction", m_params.defaultFriction);
-                m_params.defaultDensity = pConfig.GetFloat("DefaultDensity", m_params.defaultDensity);
-                m_params.collisionMargin = pConfig.GetFloat("CollisionMargin", m_params.collisionMargin);
-                m_params.gravity = pConfig.GetFloat("Gravity", m_params.gravity);
-                m_params.linearDamping = pConfig.GetFloat("LinearDamping", m_params.linearDamping);
-                m_params.angularDamping = pConfig.GetFloat("AngularDamping", m_params.angularDamping);
-                m_params.deactivationTime = pConfig.GetFloat("DeactivationTime", m_params.deactivationTime);
-                m_params.linearSleepingThreshold = pConfig.GetFloat("LinearSleepingThreshold", m_params.linearSleepingThreshold);
-                m_params.angularSleepingThreshold = pConfig.GetFloat("AngularSleepingThreshold", m_params.angularSleepingThreshold);
-                m_params.terrainFriction = pConfig.GetFloat("TerrainFriction", m_params.terrainFriction);
-                m_params.terrainHitFriction = pConfig.GetFloat("TerrainHitFriction", m_params.terrainHitFriction);
-                m_params.terrainRestitution = pConfig.GetFloat("TerrainRestitution", m_params.terrainRestitution);
-                m_params.avatarFriction = pConfig.GetFloat("AvatarFriction", m_params.avatarFriction);
-                m_params.avatarCapsuleRadius = pConfig.GetFloat("AvatarCapsuleRadius", m_params.avatarCapsuleRadius);
-                m_params.avatarCapsuleHeight = pConfig.GetFloat("AvatarCapsuleHeight", m_params.avatarCapsuleHeight);
+                _meshSculptedPrim = pConfig.GetBoolean("MeshSculptedPrim", _meshSculptedPrim);
+                _forceSimplePrimMeshing = pConfig.GetBoolean("ForceSimplePrimMeshing", _forceSimplePrimMeshing);
+
+                m_meshLOD = pConfig.GetInt("MeshLevelOfDetail", m_meshLOD);
+
+                m_maxSubSteps = pConfig.GetInt("MaxSubSteps", m_maxSubSteps);
+                m_fixedTimeStep = pConfig.GetFloat("FixedTimeStep", m_fixedTimeStep);
+                m_maxCollisionsPerFrame = pConfig.GetInt("MaxCollisionsPerFrame", m_maxCollisionsPerFrame);
+                m_maxUpdatesPerFrame = pConfig.GetInt("MaxUpdatesPerFrame", m_maxUpdatesPerFrame);
+                m_maximumObjectMass = pConfig.GetFloat("MaxObjectMass", m_maximumObjectMass);
+
+                parms.defaultFriction = pConfig.GetFloat("DefaultFriction", parms.defaultFriction);
+                parms.defaultDensity = pConfig.GetFloat("DefaultDensity", parms.defaultDensity);
+                parms.defaultRestitution = pConfig.GetFloat("DefaultRestitution", parms.defaultRestitution);
+                parms.collisionMargin = pConfig.GetFloat("CollisionMargin", parms.collisionMargin);
+                parms.gravity = pConfig.GetFloat("Gravity", parms.gravity);
+
+                parms.linearDamping = pConfig.GetFloat("LinearDamping", parms.linearDamping);
+                parms.angularDamping = pConfig.GetFloat("AngularDamping", parms.angularDamping);
+                parms.deactivationTime = pConfig.GetFloat("DeactivationTime", parms.deactivationTime);
+                parms.linearSleepingThreshold = pConfig.GetFloat("LinearSleepingThreshold", parms.linearSleepingThreshold);
+                parms.angularSleepingThreshold = pConfig.GetFloat("AngularSleepingThreshold", parms.angularSleepingThreshold);
+                parms.ccdMotionThreshold = pConfig.GetFloat("CcdMotionThreshold", parms.ccdMotionThreshold);
+                parms.ccdSweptSphereRadius = pConfig.GetFloat("CcdSweptSphereRadius", parms.ccdSweptSphereRadius);
+
+                parms.terrainFriction = pConfig.GetFloat("TerrainFriction", parms.terrainFriction);
+                parms.terrainHitFriction = pConfig.GetFloat("TerrainHitFriction", parms.terrainHitFriction);
+                parms.terrainRestitution = pConfig.GetFloat("TerrainRestitution", parms.terrainRestitution);
+                parms.avatarFriction = pConfig.GetFloat("AvatarFriction", parms.avatarFriction);
+                parms.avatarDensity = pConfig.GetFloat("AvatarDensity", parms.avatarDensity);
+                parms.avatarCapsuleRadius = pConfig.GetFloat("AvatarCapsuleRadius", parms.avatarCapsuleRadius);
+                parms.avatarCapsuleHeight = pConfig.GetFloat("AvatarCapsuleHeight", parms.avatarCapsuleHeight);
             }
         }
+        m_params[0] = parms;
     }
 
     // Called directly from unmanaged code so don't do much
@@ -282,20 +312,13 @@ public class BSScene : PhysicsScene
                                               Vector3 size, Quaternion rotation, bool isPhysical, uint localID)
     {
         // m_log.DebugFormat("{0}: AddPrimShape2: {1}", LogHeader, primName);
-        IMesh mesh = null;
-        if (NeedsMeshing(pbs))
-        {
-            // if the prim is complex, create the mesh for it.
-            // If simple (box or sphere) leave 'mesh' null and physics will do a native shape.
-            mesh = mesher.CreateMesh(primName, pbs, size, this.meshLOD, isPhysical);
-        }
-        BSPrim prim = new BSPrim(localID, primName, this, position, size, rotation, mesh, pbs, isPhysical);
+        BSPrim prim = new BSPrim(localID, primName, this, position, size, rotation, pbs, isPhysical);
         lock (m_prims) m_prims.Add(localID, prim);
         return prim;
     }
 
     // This is a call from the simulator saying that some physical property has been updated.
-    // The BulletS driver senses the changing of relevant properties so this taint 
+    // The BulletSim driver senses the changing of relevant properties so this taint 
     // information call is not needed.
     public override void AddPhysicsActorTaint(PhysicsActor prim) { }
 
@@ -307,6 +330,9 @@ public class BSScene : PhysicsScene
         int collidersCount;
         IntPtr collidersPtr;
 
+        // prevent simulation until we've been initialized
+        if (!m_initialized) return 10.0f;
+
         // update the prim states while we know the physics engine is not busy
         ProcessTaints();
 
@@ -360,7 +386,7 @@ public class BSScene : PhysicsScene
             }
         }
 
-        // fps calculation wrong. This calculation always returns about 1 in normal operation.
+        // FIX THIS: fps calculation wrong. This calculation always returns about 1 in normal operation.
         return timeStep / (numSubSteps * m_fixedTimeStep) * 1000f;
     }
 
@@ -369,8 +395,7 @@ public class BSScene : PhysicsScene
     {
         if (localID == TERRAIN_ID || localID == GROUNDPLANE_ID)
         {
-            // we never send collisions to the terrain
-            return;
+            return;         // don't send collisions to the terrain
         }
 
         ActorTypes type = ActorTypes.Prim;
@@ -381,12 +406,12 @@ public class BSScene : PhysicsScene
 
         BSPrim prim;
         if (m_prims.TryGetValue(localID, out prim)) {
-            prim.Collide(collidingWith, type, collidePoint, collideNormal, 0.01f);
+            prim.Collide(collidingWith, type, collidePoint, collideNormal, penitration);
             return;
         }
         BSCharacter actor;
         if (m_avatars.TryGetValue(localID, out actor)) {
-            actor.Collide(collidingWith, type, collidePoint, collideNormal, 0.01f);
+            actor.Collide(collidingWith, type, collidePoint, collideNormal, penitration);
             return;
         }
         return;
@@ -448,7 +473,7 @@ public class BSScene : PhysicsScene
 
         if (pbs.SculptEntry && !_meshSculptedPrim)
         {
-            // m_log.DebugFormat("{0}: NeedsMeshing: scultpy mesh", LogHeader);
+            // Render sculpties as boxes
             return false;
         }
 
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BulletSimAPI.cs b/OpenSim/Region/Physics/BulletSPlugin/BulletSimAPI.cs
index ace8158..819fce1 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BulletSimAPI.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BulletSimAPI.cs
@@ -32,12 +32,14 @@ using OpenMetaverse;
 
 namespace OpenSim.Region.Physics.BulletSPlugin {
 
+[StructLayout(LayoutKind.Sequential)]
 public struct ConvexHull 
 {
         Vector3 Offset;
         int VertexCount;
         Vector3[] Vertices;
 }
+[StructLayout(LayoutKind.Sequential)]
 public struct ShapeData 
 {
     public enum PhysicsShapeType
@@ -49,6 +51,7 @@ public struct ShapeData
                 SHAPE_SPHERE = 4,
                 SHAPE_HULL = 5
     };
+    // note that bools are passed as ints since bool size changes by language
     public const int numericTrue = 1;
     public const int numericFalse = 0;
     public uint ID;
@@ -60,11 +63,12 @@ public struct ShapeData
     public float Mass;
     public float Buoyancy;
     public System.UInt64 MeshKey;
-    public int Collidable;
     public float Friction;
+    public float Restitution;
+    public int Collidable;
     public int Static;  // true if a static object. Otherwise gravity, etc.
-    // note that bools are passed as ints since bool size changes by language
 }
+[StructLayout(LayoutKind.Sequential)]
 public struct SweepHit 
 {
     public uint ID;
@@ -72,12 +76,14 @@ public struct SweepHit
     public Vector3 Normal;
     public Vector3 Point;
 }
+[StructLayout(LayoutKind.Sequential)]
 public struct RaycastHit
 {
     public uint ID;
     public float Fraction;
     public Vector3 Normal;
 }
+[StructLayout(LayoutKind.Sequential)]
 public struct CollisionDesc
 {
     public uint aID;
@@ -85,6 +91,7 @@ public struct CollisionDesc
     public Vector3 point;
     public Vector3 normal;
 }
+[StructLayout(LayoutKind.Sequential)]
 public struct EntityProperties
 {
     public uint ID;
@@ -92,13 +99,42 @@ public struct EntityProperties
     public Quaternion Rotation;
     public Vector3 Velocity;
     public Vector3 Acceleration;
-    public Vector3 AngularVelocity;
+    public Vector3 RotationalVelocity;
+}
+
+// Format of this structure must match the definition in the C++ code
+[StructLayout(LayoutKind.Sequential)]
+public struct ConfigurationParameters
+{
+    public float defaultFriction;
+    public float defaultDensity;
+    public float defaultRestitution;
+    public float collisionMargin;
+    public float gravity;
+
+    public float linearDamping;
+    public float angularDamping;
+    public float deactivationTime;
+    public float linearSleepingThreshold;
+    public float angularSleepingThreshold;
+        public float ccdMotionThreshold;
+        public float ccdSweptSphereRadius;
+
+    public float terrainFriction;
+    public float terrainHitFriction;
+    public float terrainRestitution;
+    public float avatarFriction;
+    public float avatarDensity;
+    public float avatarRestitution;
+    public float avatarCapsuleRadius;
+    public float avatarCapsuleHeight;
 }
 
 static class BulletSimAPI {
 
 [DllImport("BulletSim", CallingConvention = CallingConvention.Cdecl), SuppressUnmanagedCodeSecurity]
-public static extern uint Initialize(Vector3 maxPosition, int maxCollisions, IntPtr collisionArray, 
+public static extern uint Initialize(Vector3 maxPosition, IntPtr parms, 
+                        int maxCollisions, IntPtr collisionArray, 
                         int maxUpdates, IntPtr updateArray);
 
 [DllImport("BulletSim", CallingConvention = CallingConvention.Cdecl), SuppressUnmanagedCodeSecurity]
diff --git a/bin/BulletSim-x86_64.dll b/bin/BulletSim-x86_64.dll
index bcdea44..750b2f5 100755
--- a/bin/BulletSim-x86_64.dll
+++ b/bin/BulletSim-x86_64.dll
diff --git a/bin/BulletSim.dll b/bin/BulletSim.dll
index 5dc51db..d5c76da 100755
--- a/bin/BulletSim.dll
+++ b/bin/BulletSim.dll
diff --git a/bin/OpenSimDefaults.ini b/bin/OpenSimDefaults.ini
index bf36228..d487ce6 100644
--- a/bin/OpenSimDefaults.ini
+++ b/bin/OpenSimDefaults.ini
@@ -159,6 +159,7 @@
     ;physics = basicphysics
     ;physics = POS
     ;physics = modified_BulletX
+    ;physics = BulletSim
 
     ; ##
     ; ## PERMISSIONS
@@ -725,6 +726,47 @@
     ; true. Note that this will increase memory usage and region startup time. Default is false.
     ;force_simple_prim_meshing = true
 
+[BulletSim]
+    ; World parameters
+    DefaultFriction = 0.70
+    DefaultDensity = 10.000006836
+    DefaultRestitution = 0.0
+    Gravity = -9.80665
+
+    TerrainFriction = 0.85
+    TerrainHitFriction = 0.8
+    TerrainRestitution = 0.2
+    AvatarFriction = 0.85
+    AvatarDensity = 60.0
+    AvatarCapsuleRadius = 0.37
+    AvatarCapsuleHeight = 1.5
+
+    MaxObjectMass = 10000.01
+
+    ; Dynamic parameters
+    LinearDamping = 0.0
+    AngularDamping = 0.0
+    DeactivationTime = 0.2
+    LinearSleepingThreshold = 0.8
+    AngularSleepingThreshold = 1.0
+    CcdMotionThreshold = 0.5
+    CcdSweptSphereRadius = 0.2
+
+    ; Whether to mesh sculpties
+    MeshSculptedPrim = true
+
+    ; If 'true', force simple prims (box and sphere) to be meshed
+    ForceSimplePrimMeshing = false
+
+    ; number^2 non-physical level of detail of the sculpt texture.  32x32 - 1024 verticies
+    MeshLevelOfDetail = 32
+
+    ; Bullet step parameters
+    MaxSubSteps = 10;
+    FixedTimeStep = .01667
+
+    MaxCollisionsPerFrame = 2048
+    MaxUpdatesPerFrame = 2048
 
 [RemoteAdmin]
     enabled = false
diff --git a/bin/libBulletSim.so b/bin/libBulletSim.so
index 82d3b34..275355d 100755
--- a/bin/libBulletSim.so
+++ b/bin/libBulletSim.so