From 5f71ee57c44f277e9e78392c616509498459c027 Mon Sep 17 00:00:00 2001
From: Robert Adams <Robert.Adams@intel.com>
Date: Tue, 25 Dec 2012 23:54:10 -0800
Subject: [PATCH 01/13] BulletSim: stop avatar from sliding VERY slowly after
 walking by only zeroing the movement motor in the UpdateProperties routine.

---
 OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs b/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
index bf0545afb1..9f0d5afdbe 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
@@ -260,7 +260,6 @@ public sealed class BSCharacter : BSPhysObject
     public override void ZeroMotion(bool inTaintTime)
     {
         _velocity = OMV.Vector3.Zero;
-        _velocityMotor.Zero();
         _acceleration = OMV.Vector3.Zero;
         _rotationalVelocity = OMV.Vector3.Zero;
 
@@ -772,9 +771,9 @@ public sealed class BSCharacter : BSPhysObject
             //     the motor can be turned off. Set the velocity to zero so the zero motion is sent to the viewer.
             if (_velocityMotor.TargetValue.ApproxEquals(OMV.Vector3.Zero, 0.01f) && _velocityMotor.ErrorIsZero)
             {
-                _velocityMotor.Enabled = false;
-                stepVelocity = OMV.Vector3.Zero;
                 ZeroMotion(true);
+                stepVelocity = OMV.Vector3.Zero;
+                _velocityMotor.Enabled = false;
                 DetailLog("{0},BSCharacter.UpdateProperties,taint,disableVelocityMotor,m={1}", LocalID, _velocityMotor);
             }
 

From d1ede1df3a04428c83a9937059a0df00d7f3e281 Mon Sep 17 00:00:00 2001
From: Robert Adams <Robert.Adams@intel.com>
Date: Tue, 25 Dec 2012 23:55:25 -0800
Subject: [PATCH 02/13] BulletSim: make llBuoyancy work. For some reason,
 Bullet resets an object's individual gravity to the world gravity when the
 object is added to the physical world.

---
 OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs   |  3 +++
 OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs       | 12 ++++++++----
 .../Region/Physics/BulletSPlugin/BulletSimTODO.txt   |  3 ++-
 3 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs b/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
index 3fde57bed4..a8edd2305b 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
@@ -573,6 +573,9 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                 BulletSimAPI.SetMassProps2(Prim.PhysBody.ptr, m_vehicleMass, localInertia);
                 BulletSimAPI.UpdateInertiaTensor2(Prim.PhysBody.ptr);
 
+                Vector3 grav = PhysicsScene.DefaultGravity * (1f - Prim.Buoyancy);
+                BulletSimAPI.SetGravity2(Prim.PhysBody.ptr, grav);
+
                 VDetailLog("{0},BSDynamics.Refresh,mass={1},frict={2},inert={3},aDamp={4}",
                                 Prim.LocalID, m_vehicleMass, friction, localInertia, angularDamping);
             }
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
index 159f79f922..0d130964dd 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
@@ -422,20 +422,24 @@ public sealed class BSPrim : BSPhysObject
                     BulletSimAPI.RemoveObjectFromWorld2(PhysicsScene.World.ptr, PhysBody.ptr);
                 }
 
-                float grav = PhysicsScene.Params.gravity * (1f - _buoyancy);
-                BulletSimAPI.SetGravity2(PhysBody.ptr, new OMV.Vector3(0f, 0f, grav));
-
                 Inertia = BulletSimAPI.CalculateLocalInertia2(PhysShape.ptr, physMass);
                 BulletSimAPI.SetMassProps2(PhysBody.ptr, physMass, Inertia);
                 BulletSimAPI.UpdateInertiaTensor2(PhysBody.ptr);
+
                 // center of mass is at the zero of the object
                 // DEBUG DEBUG BulletSimAPI.SetCenterOfMassByPosRot2(PhysBody.ptr, ForcePosition, ForceOrientation);
-                DetailLog("{0},BSPrim.UpdateMassProperties,mass={1},localInertia={2}", LocalID, physMass, Inertia);
+                DetailLog("{0},BSPrim.UpdateMassProperties,mass={1},localInertia={2},inWorld={3}", LocalID, physMass, Inertia, inWorld);
 
                 if (inWorld)
                 {
                     BulletSimAPI.AddObjectToWorld2(PhysicsScene.World.ptr, PhysBody.ptr);
                 }
+
+                // Must set gravity after it has been added to the world because, for unknown reasons,
+                //     adding the object resets the object's gravity to world gravity
+                OMV.Vector3 grav = PhysicsScene.DefaultGravity * (1f - Buoyancy);
+                BulletSimAPI.SetGravity2(PhysBody.ptr, grav);
+
             }
         }
     }
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt b/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
index 35cb8f3d49..9d07d72fdb 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
+++ b/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
@@ -58,7 +58,6 @@ Incorporate inter-relationship of angular corrections. For instance, angularDefl
 
 BULLETSIM TODO LIST:
 =================================================
-In SL, perfect spheres don't seem to have rolling friction. Add special case.
 Avatar density is WAY off. Compare and calibrate with what's in SL.
 Revisit CollisionMargin. Builders notice the 0.04 spacing between prims.
 Duplicating a physical prim causes old prim to jump away
@@ -146,6 +145,8 @@ Is there are more efficient method of implementing pre and post step actions?
 	See http://www.codeproject.com/Articles/29922/Weak-Events-in-C
 
 Physics Arena central pyramid: why is one side permiable?
+
+In SL, perfect spheres don't seem to have rolling friction. Add special case.
 Enforce physical parameter min/max:
 	Gravity: [-1, 28]
 	Friction: [0, 255]

From 225b564573a5ac12ca1b1e592834476feccf8ebb Mon Sep 17 00:00:00 2001
From: Robert Adams <Robert.Adams@intel.com>
Date: Wed, 26 Dec 2012 10:25:50 -0800
Subject: [PATCH 03/13] BulletSim: scale the force for external AddForce by the
 simulation step time so it will be applied completely the next step. The
 internal AddForce routine does not scale the force.

---
 OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs       | 12 +++++++++++-
 OpenSim/Region/Physics/BulletSPlugin/BSScene.cs      |  4 ++++
 .../Region/Physics/BulletSPlugin/BulletSimTODO.txt   |  4 ++++
 3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
index 0d130964dd..901341444e 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
@@ -1014,7 +1014,9 @@ public sealed class BSPrim : BSPhysObject
     public override float APIDDamping { set { return; } }
 
     public override void AddForce(OMV.Vector3 force, bool pushforce) {
-        AddForce(force, pushforce, false);
+        // Since this force is being applied in only one step, make this a force per second.
+        OMV.Vector3 addForce = force / PhysicsScene.LastTimeStep;
+        AddForce(addForce, pushforce, false);
     }
     // Applying a force just adds this to the total force on the object.
     // This added force will only last the next simulation tick.
@@ -1022,8 +1024,16 @@ public sealed class BSPrim : BSPhysObject
         // for an object, doesn't matter if force is a pushforce or not
         if (force.IsFinite())
         {
+            float magnitude = force.Length();
+            if (magnitude > 20000f)
+            {
+                // Force has a limit
+                force = force / magnitude * 20000f;
+            }
+
             OMV.Vector3 addForce = force;
             DetailLog("{0},BSPrim.addForce,call,force={1}", LocalID, addForce);
+
             PhysicsScene.TaintedObject(inTaintTime, "BSPrim.AddForce", delegate()
             {
                 // Bullet adds this central force to the total force for this tick
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs b/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
index 0022e45cde..b67c0ed532 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
@@ -495,6 +495,10 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
 
         InTaintTime = false; // Only used for debugging so locking is not necessary.
 
+        // The following causes the unmanaged code to output ALL the values found in ALL the objects in the world.
+        // Only enable this in a limited test world with few objects.
+        // BulletSimAPI.DumpAllInfo2(World.ptr);    // DEBUG DEBUG DEBUG
+
         // step the physical world one interval
         m_simulationStep++;
         int numSubSteps = 0;
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt b/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
index 9d07d72fdb..78cc26c780 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
+++ b/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
@@ -35,6 +35,8 @@ Border crossing with linked vehicle causes crash
 Vehicles (Move smoothly)
 Add vehicle collisions so IsColliding is properly reported.
 	Needed for banking, limitMotorUp, movementLimiting, ...
+VehicleAddForce is not scaled by the simulation step but it is only
+	applied for one step. Should it be scaled?
 Some vehicles should not be able to turn if no speed or off ground.
 Cannot edit/move a vehicle being ridden: it jumps back to the origional position.
 Neb car jiggling left and right
@@ -92,6 +94,8 @@ Should the different PID factors have non-equal contributions for different
 Selecting and deselecting physical objects causes CPU processing time to jump
 	http://www.youtube.com/watch?v=Hjg57fWg8yI&hd=1
 	put thousand physical objects, select and deselect same. CPU time will be large.
+Re-implement buoyancy as a separate force on the object rather than diddling gravity.
+	Register a pre-step event to add the force.
 
 LINKSETS
 ======================================================

From 29cdf0f3dd99605192f29fc83bbacdf8ecb0ea8d Mon Sep 17 00:00:00 2001
From: teravus <teravus@gmail.com>
Date: Tue, 18 Dec 2012 15:00:10 -0500
Subject: [PATCH 04/13] * Merges BulletSim Updates to
 BulletSimN(BulletSNPlugin)

---
 .../Physics/BulletSNPlugin/BSCharacter.cs     |  8 +-
 .../Physics/BulletSNPlugin/BSConstraint.cs    |  2 +-
 .../BulletSNPlugin/BSConstraint6Dof.cs        |  4 +-
 .../BulletSNPlugin/BSConstraintCollection.cs  |  4 +-
 .../BulletSNPlugin/BSConstraintHinge.cs       |  2 +-
 .../Physics/BulletSNPlugin/BSDynamics.cs      |  3 +
 .../Physics/BulletSNPlugin/BSLinkset.cs       | 20 ++---
 .../BulletSNPlugin/BSLinksetCompound.cs       | 11 +--
 .../BulletSNPlugin/BSLinksetConstraints.cs    |  6 +-
 .../Physics/BulletSNPlugin/BSMaterials.cs     | 16 ++--
 .../Region/Physics/BulletSNPlugin/BSParam.cs  |  2 +-
 .../Physics/BulletSNPlugin/BSPhysObject.cs    |  3 +-
 .../Region/Physics/BulletSNPlugin/BSPrim.cs   | 87 +++++++++++++------
 .../Region/Physics/BulletSNPlugin/BSScene.cs  | 11 ++-
 .../BulletSNPlugin/BSShapeCollection.cs       |  6 +-
 .../BulletSNPlugin/BSTerrainHeightmap.cs      |  2 +-
 .../BulletSNPlugin/BSTerrainManager.cs        |  3 +-
 .../Physics/BulletSNPlugin/BulletSimAPI.cs    |  1 -
 .../Physics/BulletSNPlugin/BulletSimData.cs   |  4 +-
 19 files changed, 116 insertions(+), 79 deletions(-)

diff --git a/OpenSim/Region/Physics/BulletSNPlugin/BSCharacter.cs b/OpenSim/Region/Physics/BulletSNPlugin/BSCharacter.cs
index 4c4e95048f..d91c47f1a3 100644
--- a/OpenSim/Region/Physics/BulletSNPlugin/BSCharacter.cs
+++ b/OpenSim/Region/Physics/BulletSNPlugin/BSCharacter.cs
@@ -174,7 +174,7 @@ public sealed class BSCharacter : BSPhysObject
             BulletSimAPI.SetCcdSweptSphereRadius2(PhysBody.ptr, BSParam.CcdSweptSphereRadius);
         }
 
-        UpdatePhysicalMassProperties(RawMass);
+        UpdatePhysicalMassProperties(RawMass, false);
 
         // Make so capsule does not fall over
         BulletSimAPI.SetAngularFactorV2(PhysBody.ptr, OMV.Vector3.Zero);
@@ -224,7 +224,7 @@ public sealed class BSCharacter : BSPhysObject
                 if (PhysBody.HasPhysicalBody && PhysShape.HasPhysicalShape)
                 {
                     BulletSimAPI.SetLocalScaling2(PhysShape.ptr, Scale);
-                    UpdatePhysicalMassProperties(RawMass);
+                    UpdatePhysicalMassProperties(RawMass, true);
                     // Make sure this change appears as a property update event
                     BulletSimAPI.PushUpdate2(PhysBody.ptr);
                 }
@@ -260,7 +260,6 @@ public sealed class BSCharacter : BSPhysObject
     public override void ZeroMotion(bool inTaintTime)
     {
         _velocity = OMV.Vector3.Zero;
-        _velocityMotor.Zero();
         _acceleration = OMV.Vector3.Zero;
         _rotationalVelocity = OMV.Vector3.Zero;
 
@@ -390,7 +389,7 @@ public sealed class BSCharacter : BSPhysObject
     public override float RawMass { 
         get {return _mass; }
     }
-    public override void UpdatePhysicalMassProperties(float physMass)
+    public override void UpdatePhysicalMassProperties(float physMass, bool inWorld)
     {
         OMV.Vector3 localInertia = BulletSimAPI.CalculateLocalInertia2(PhysShape.ptr, physMass);
         BulletSimAPI.SetMassProps2(PhysBody.ptr, physMass, localInertia);
@@ -787,6 +786,7 @@ public sealed class BSCharacter : BSPhysObject
             //     the motor can be turned off. Set the velocity to zero so the zero motion is sent to the viewer.
             if (_velocityMotor.TargetValue.ApproxEquals(OMV.Vector3.Zero, 0.01f) && _velocityMotor.ErrorIsZero)
             {
+                ZeroMotion(true);
                 stepVelocity = OMV.Vector3.Zero;
                 _velocityMotor.Enabled = false;
                 DetailLog("{0},BSCharacter.UpdateProperties,taint,disableVelocityMotor,m={1}", LocalID, _velocityMotor);
diff --git a/OpenSim/Region/Physics/BulletSNPlugin/BSConstraint.cs b/OpenSim/Region/Physics/BulletSNPlugin/BSConstraint.cs
index 426bdc2ea7..f1bed3987b 100644
--- a/OpenSim/Region/Physics/BulletSNPlugin/BSConstraint.cs
+++ b/OpenSim/Region/Physics/BulletSNPlugin/BSConstraint.cs
@@ -36,7 +36,7 @@ public abstract class BSConstraint : IDisposable
 {
     private static string LogHeader = "[BULLETSIM CONSTRAINT]";
 
-    protected BulletSim m_world;
+    protected BulletWorld m_world;
     protected BulletBody m_body1;
     protected BulletBody m_body2;
     protected BulletConstraint m_constraint;
diff --git a/OpenSim/Region/Physics/BulletSNPlugin/BSConstraint6Dof.cs b/OpenSim/Region/Physics/BulletSNPlugin/BSConstraint6Dof.cs
index 0181d9dffb..d1e3f550a1 100644
--- a/OpenSim/Region/Physics/BulletSNPlugin/BSConstraint6Dof.cs
+++ b/OpenSim/Region/Physics/BulletSNPlugin/BSConstraint6Dof.cs
@@ -39,7 +39,7 @@ public sealed class BSConstraint6Dof : BSConstraint
     public override ConstraintType Type { get { return ConstraintType.D6_CONSTRAINT_TYPE; } }
 
     // Create a btGeneric6DofConstraint
-    public BSConstraint6Dof(BulletSim world, BulletBody obj1, BulletBody obj2,
+    public BSConstraint6Dof(BulletWorld world, BulletBody obj1, BulletBody obj2,
                     Vector3 frame1, Quaternion frame1rot,
                     Vector3 frame2, Quaternion frame2rot,
                     bool useLinearReferenceFrameA, bool disableCollisionsBetweenLinkedBodies)
@@ -58,7 +58,7 @@ public sealed class BSConstraint6Dof : BSConstraint
                             obj1.ID, obj1.ptr.ToString(), obj2.ID, obj2.ptr.ToString());
     }
 
-    public BSConstraint6Dof(BulletSim world, BulletBody obj1, BulletBody obj2,
+    public BSConstraint6Dof(BulletWorld world, BulletBody obj1, BulletBody obj2,
                     Vector3 joinPoint,
                     bool useLinearReferenceFrameA, bool disableCollisionsBetweenLinkedBodies)
     {
diff --git a/OpenSim/Region/Physics/BulletSNPlugin/BSConstraintCollection.cs b/OpenSim/Region/Physics/BulletSNPlugin/BSConstraintCollection.cs
index 5c00b1a3ce..87d1e44d30 100644
--- a/OpenSim/Region/Physics/BulletSNPlugin/BSConstraintCollection.cs
+++ b/OpenSim/Region/Physics/BulletSNPlugin/BSConstraintCollection.cs
@@ -41,9 +41,9 @@ public sealed class BSConstraintCollection : IDisposable
     delegate bool ConstraintAction(BSConstraint constrain);
 
     private List<BSConstraint> m_constraints;
-    private BulletSim m_world;
+    private BulletWorld m_world;
 
-    public BSConstraintCollection(BulletSim world)
+    public BSConstraintCollection(BulletWorld world)
     {
         m_world = world;
         m_constraints = new List<BSConstraint>();
diff --git a/OpenSim/Region/Physics/BulletSNPlugin/BSConstraintHinge.cs b/OpenSim/Region/Physics/BulletSNPlugin/BSConstraintHinge.cs
index 7951f06b18..fbd1bc0c21 100644
--- a/OpenSim/Region/Physics/BulletSNPlugin/BSConstraintHinge.cs
+++ b/OpenSim/Region/Physics/BulletSNPlugin/BSConstraintHinge.cs
@@ -36,7 +36,7 @@ public sealed class BSConstraintHinge : BSConstraint
 {
     public override ConstraintType Type { get { return ConstraintType.HINGE_CONSTRAINT_TYPE; } }
 
-    public BSConstraintHinge(BulletSim world, BulletBody obj1, BulletBody obj2,
+    public BSConstraintHinge(BulletWorld world, BulletBody obj1, BulletBody obj2,
                     Vector3 pivotInA, Vector3 pivotInB,
                     Vector3 axisInA, Vector3 axisInB,
                     bool useLinearReferenceFrameA, bool disableCollisionsBetweenLinkedBodies)
diff --git a/OpenSim/Region/Physics/BulletSNPlugin/BSDynamics.cs b/OpenSim/Region/Physics/BulletSNPlugin/BSDynamics.cs
index 72afacc8f1..415ad4f34f 100644
--- a/OpenSim/Region/Physics/BulletSNPlugin/BSDynamics.cs
+++ b/OpenSim/Region/Physics/BulletSNPlugin/BSDynamics.cs
@@ -573,6 +573,9 @@ namespace OpenSim.Region.Physics.BulletSNPlugin
                 BulletSimAPI.SetMassProps2(Prim.PhysBody.ptr, m_vehicleMass, localInertia);
                 BulletSimAPI.UpdateInertiaTensor2(Prim.PhysBody.ptr);
 
+                Vector3 grav = PhysicsScene.DefaultGravity * (1f - Prim.Buoyancy);
+                BulletSimAPI.SetGravity2(Prim.PhysBody.ptr, grav);
+
                 VDetailLog("{0},BSDynamics.Refresh,mass={1},frict={2},inert={3},aDamp={4}",
                                 Prim.LocalID, m_vehicleMass, friction, localInertia, angularDamping);
             }
diff --git a/OpenSim/Region/Physics/BulletSNPlugin/BSLinkset.cs b/OpenSim/Region/Physics/BulletSNPlugin/BSLinkset.cs
index 253128b4ba..845a1136c5 100644
--- a/OpenSim/Region/Physics/BulletSNPlugin/BSLinkset.cs
+++ b/OpenSim/Region/Physics/BulletSNPlugin/BSLinkset.cs
@@ -97,14 +97,7 @@ public abstract class BSLinkset
     }
 
     // We keep the prim's mass in the linkset structure since it could be dependent on other prims
-    protected float m_mass;
-    public float LinksetMass
-    {
-        get
-        {
-            return m_mass;
-        }
-    }
+    public float LinksetMass { get; protected set; }
 
     public virtual bool LinksetIsColliding { get { return false; } }
 
@@ -128,7 +121,7 @@ public abstract class BSLinkset
         PhysicsScene = scene;
         LinksetRoot = parent;
         m_children = new HashSet<BSPhysObject>();
-        m_mass = parent.RawMass;
+        LinksetMass = parent.RawMass;
         Rebuilding = false;
     }
 
@@ -143,7 +136,7 @@ public abstract class BSLinkset
             // Don't add the root to its own linkset
             if (!IsRoot(child))
                 AddChildToLinkset(child);
-            m_mass = ComputeLinksetMass();
+            LinksetMass = ComputeLinksetMass();
         }
         return this;
     }
@@ -162,7 +155,7 @@ public abstract class BSLinkset
                 return this;
             }
             RemoveChildFromLinkset(child);
-            m_mass = ComputeLinksetMass();
+            LinksetMass = ComputeLinksetMass();
         }
 
         // The child is down to a linkset of just itself
@@ -230,7 +223,10 @@ public abstract class BSLinkset
     // When physical properties are changed the linkset needs to recalculate
     //   its internal properties.
     // May be called at runtime or taint-time.
-    public abstract void Refresh(BSPhysObject requestor);
+    public virtual void Refresh(BSPhysObject requestor)
+    {
+        LinksetMass = ComputeLinksetMass();
+    }
 
     // Flag denoting the linkset is in the process of being rebuilt.
     // Used to know not the schedule a rebuild in the middle of a rebuild.
diff --git a/OpenSim/Region/Physics/BulletSNPlugin/BSLinksetCompound.cs b/OpenSim/Region/Physics/BulletSNPlugin/BSLinksetCompound.cs
index 23a0b8bbf6..9a977e6ad2 100644
--- a/OpenSim/Region/Physics/BulletSNPlugin/BSLinksetCompound.cs
+++ b/OpenSim/Region/Physics/BulletSNPlugin/BSLinksetCompound.cs
@@ -89,6 +89,8 @@ public sealed class BSLinksetCompound : BSLinkset
     //   its internal properties.
     public override void Refresh(BSPhysObject requestor)
     {
+        base.Refresh(requestor);
+
         // Something changed so do the rebuilding thing
         // ScheduleRebuild();
     }
@@ -96,13 +98,13 @@ public sealed class BSLinksetCompound : BSLinkset
     // Schedule a refresh to happen after all the other taint processing.
     private void ScheduleRebuild(BSPhysObject requestor)
     {
-        DetailLog("{0},BSLinksetCompound.Refresh,schedulingRefresh,rebuilding={1}", 
+        DetailLog("{0},BSLinksetCompound.ScheduleRebuild,,rebuilding={1}", 
                             requestor.LocalID, Rebuilding);
         // When rebuilding, it is possible to set properties that would normally require a rebuild.
         //    If already rebuilding, don't request another rebuild.
         if (!Rebuilding)
         {
-            PhysicsScene.PostTaintObject("BSLinksetCompound.Refresh", LinksetRoot.LocalID, delegate()
+            PhysicsScene.PostTaintObject("BSLinksetCompound.ScheduleRebuild", LinksetRoot.LocalID, delegate()
             {
                 if (HasAnyChildren)
                     RecomputeLinksetCompound();
@@ -123,7 +125,6 @@ public sealed class BSLinksetCompound : BSLinkset
         if (IsRoot(child))
         {
             // The root is going dynamic. Make sure mass is properly set.
-            m_mass = ComputeLinksetMass();
             ScheduleRebuild(LinksetRoot);
         }
         else
@@ -377,8 +378,8 @@ public sealed class BSLinksetCompound : BSLinkset
             });
 
             // With all of the linkset packed into the root prim, it has the mass of everyone.
-            float linksetMass = LinksetMass;
-            LinksetRoot.UpdatePhysicalMassProperties(linksetMass);
+            LinksetMass = LinksetMass;
+            LinksetRoot.UpdatePhysicalMassProperties(LinksetMass, true);
         }
         finally
         {
diff --git a/OpenSim/Region/Physics/BulletSNPlugin/BSLinksetConstraints.cs b/OpenSim/Region/Physics/BulletSNPlugin/BSLinksetConstraints.cs
index 5757e64e78..46ff99f98d 100644
--- a/OpenSim/Region/Physics/BulletSNPlugin/BSLinksetConstraints.cs
+++ b/OpenSim/Region/Physics/BulletSNPlugin/BSLinksetConstraints.cs
@@ -46,6 +46,8 @@ public sealed class BSLinksetConstraints : BSLinkset
     //   refresh will happen once after all the other taints are applied.
     public override void Refresh(BSPhysObject requestor)
     {
+        base.Refresh(requestor);
+
         // Queue to happen after all the other taint processing
         PhysicsScene.PostTaintObject("BSLinksetContraints.Refresh", requestor.LocalID, delegate()
             {
@@ -279,7 +281,7 @@ public sealed class BSLinksetConstraints : BSLinkset
     private void RecomputeLinksetConstraints()
     {
         float linksetMass = LinksetMass;
-        LinksetRoot.UpdatePhysicalMassProperties(linksetMass);
+        LinksetRoot.UpdatePhysicalMassProperties(linksetMass, true);
 
         // DEBUG: see of inter-linkset collisions are causing problems
         // BulletSimAPI.SetCollisionFilterMask2(LinksetRoot.BSBody.ptr, 
@@ -292,7 +294,7 @@ public sealed class BSLinksetConstraints : BSLinkset
             // A child in the linkset physically shows the mass of the whole linkset.
             // This allows Bullet to apply enough force on the child to move the whole linkset.
             // (Also do the mass stuff before recomputing the constraint so mass is not zero.)
-            child.UpdatePhysicalMassProperties(linksetMass);
+            child.UpdatePhysicalMassProperties(linksetMass, true);
 
             BSConstraint constrain;
             if (!PhysicsScene.Constraints.TryGetConstraint(LinksetRoot.PhysBody, child.PhysBody, out constrain))
diff --git a/OpenSim/Region/Physics/BulletSNPlugin/BSMaterials.cs b/OpenSim/Region/Physics/BulletSNPlugin/BSMaterials.cs
index 732191f9b6..d7941b6f1a 100644
--- a/OpenSim/Region/Physics/BulletSNPlugin/BSMaterials.cs
+++ b/OpenSim/Region/Physics/BulletSNPlugin/BSMaterials.cs
@@ -119,26 +119,26 @@ public static class BSMaterials
         Attributes[(int)MaterialAttributes.Material.Light] =
                     new MaterialAttributes("light",dDensity, dFriction, dRestitution);
         Attributes[(int)MaterialAttributes.Material.Avatar] =
-                    new MaterialAttributes("avatar",60f, 0.2f, 0f);
+                    new MaterialAttributes("avatar",3.5f, 0.2f, 0f);
 
         Attributes[(int)MaterialAttributes.Material.Stone + (int)MaterialAttributes.Material.NumberOfTypes] =
                     new MaterialAttributes("stonePhysical",dDensity, 0.8f, 0.4f);
         Attributes[(int)MaterialAttributes.Material.Metal + (int)MaterialAttributes.Material.NumberOfTypes] =
-                    new MaterialAttributes("metalPhysical",dDensity, 0.8f, 0.4f);
+                    new MaterialAttributes("metalPhysical",dDensity, 0.3f, 0.4f);
         Attributes[(int)MaterialAttributes.Material.Glass + (int)MaterialAttributes.Material.NumberOfTypes] =
-                    new MaterialAttributes("glassPhysical",dDensity, 0.8f, 0.7f);
+                    new MaterialAttributes("glassPhysical",dDensity, 0.2f, 0.7f);
         Attributes[(int)MaterialAttributes.Material.Wood + (int)MaterialAttributes.Material.NumberOfTypes] =
-                    new MaterialAttributes("woodPhysical",dDensity, 0.8f, 0.5f);
+                    new MaterialAttributes("woodPhysical",dDensity, 0.6f, 0.5f);
         Attributes[(int)MaterialAttributes.Material.Flesh + (int)MaterialAttributes.Material.NumberOfTypes] =
-                    new MaterialAttributes("fleshPhysical",dDensity, 0.8f, 0.3f);
+                    new MaterialAttributes("fleshPhysical",dDensity, 0.9f, 0.3f);
         Attributes[(int)MaterialAttributes.Material.Plastic + (int)MaterialAttributes.Material.NumberOfTypes] =
-                    new MaterialAttributes("plasticPhysical",dDensity, 0.8f, 0.7f);
+                    new MaterialAttributes("plasticPhysical",dDensity, 0.4f, 0.7f);
         Attributes[(int)MaterialAttributes.Material.Rubber + (int)MaterialAttributes.Material.NumberOfTypes] =
-                    new MaterialAttributes("rubberPhysical",dDensity, 0.8f, 0.9f);
+                    new MaterialAttributes("rubberPhysical",dDensity, 0.9f, 0.9f);
         Attributes[(int)MaterialAttributes.Material.Light + (int)MaterialAttributes.Material.NumberOfTypes] =
                     new MaterialAttributes("lightPhysical",dDensity, dFriction, dRestitution);
         Attributes[(int)MaterialAttributes.Material.Avatar + (int)MaterialAttributes.Material.NumberOfTypes] =
-                    new MaterialAttributes("avatarPhysical",60f, 0.2f, 0f);
+                    new MaterialAttributes("avatarPhysical",3.5f, 0.2f, 0f);
     }
 
     // Under the [BulletSim] section, one can change the individual material
diff --git a/OpenSim/Region/Physics/BulletSNPlugin/BSParam.cs b/OpenSim/Region/Physics/BulletSNPlugin/BSParam.cs
index 20c0939871..5e93a0335a 100644
--- a/OpenSim/Region/Physics/BulletSNPlugin/BSParam.cs
+++ b/OpenSim/Region/Physics/BulletSNPlugin/BSParam.cs
@@ -351,7 +351,7 @@ public static class BSParam
             (s) => { return AvatarStandingFriction; },
             (s,p,l,v) => { AvatarStandingFriction = v; } ),
         new ParameterDefn("AvatarDensity", "Density of an avatar. Changed on avatar recreation.",
-            60f,
+            3.5f,
             (s,cf,p,v) => { AvatarDensity = cf.GetFloat(p, v); },
             (s) => { return AvatarDensity; },
             (s,p,l,v) => { s.UpdateParameterObject((x)=>{AvatarDensity=x;}, p, l, v); } ),
diff --git a/OpenSim/Region/Physics/BulletSNPlugin/BSPhysObject.cs b/OpenSim/Region/Physics/BulletSNPlugin/BSPhysObject.cs
index 4096ef8583..689da7f962 100644
--- a/OpenSim/Region/Physics/BulletSNPlugin/BSPhysObject.cs
+++ b/OpenSim/Region/Physics/BulletSNPlugin/BSPhysObject.cs
@@ -96,7 +96,8 @@ public abstract class BSPhysObject : PhysicsActor
     // Return the object mass without calculating it or having side effects
     public abstract float RawMass { get; }
     // Set the raw mass but also update physical mass properties (inertia, ...)
-    public abstract void UpdatePhysicalMassProperties(float mass);
+    // 'inWorld' true if the object has already been added to the dynamic world.
+    public abstract void UpdatePhysicalMassProperties(float mass, bool inWorld);
 
     // The last value calculated for the prim's inertia
     public OMV.Vector3 Inertia { get; set; }
diff --git a/OpenSim/Region/Physics/BulletSNPlugin/BSPrim.cs b/OpenSim/Region/Physics/BulletSNPlugin/BSPrim.cs
index a889c2415f..9c4ba3021f 100644
--- a/OpenSim/Region/Physics/BulletSNPlugin/BSPrim.cs
+++ b/OpenSim/Region/Physics/BulletSNPlugin/BSPrim.cs
@@ -115,6 +115,8 @@ public sealed class BSPrim : BSPhysObject
         PhysBody = new BulletBody(LocalID);
         PhysShape = new BulletShape();
 
+        Linkset.Refresh(this);
+
         DetailLog("{0},BSPrim.constructor,call", LocalID);
         // do the actual object creation at taint time
         PhysicsScene.TaintedObject("BSPrim.create", delegate()
@@ -384,13 +386,13 @@ public sealed class BSPrim : BSPhysObject
     }
 
     // Return the effective mass of the object.
-    // If there are multiple items in the linkset, add them together for the root
+        // The definition of this call is to return the mass of the prim.
+        // If the simulator cares about the mass of the linkset, it will sum it itself.
     public override float Mass
     {
         get
         {
-            return Linkset.LinksetMass;
-            // return _mass;
+            return _mass;
         }
     }
 
@@ -400,22 +402,45 @@ public sealed class BSPrim : BSPhysObject
     }
     // Set the physical mass to the passed mass.
     // Note that this does not change _mass!
-    public override void UpdatePhysicalMassProperties(float physMass)
+    public override void UpdatePhysicalMassProperties(float physMass, bool inWorld)
     {
-        if (IsStatic)
+        if (PhysBody.HasPhysicalBody)
         {
-            Inertia = OMV.Vector3.Zero;
-            BulletSimAPI.SetMassProps2(PhysBody.ptr, 0f, Inertia);
-            BulletSimAPI.UpdateInertiaTensor2(PhysBody.ptr);
-        }
-        else
-        {
-            Inertia = BulletSimAPI.CalculateLocalInertia2(PhysShape.ptr, physMass);
-            BulletSimAPI.SetMassProps2(PhysBody.ptr, physMass, Inertia);
-            BulletSimAPI.UpdateInertiaTensor2(PhysBody.ptr);
-            // center of mass is at the zero of the object
-            // DEBUG DEBUG BulletSimAPI.SetCenterOfMassByPosRot2(PhysBody.ptr, ForcePosition, ForceOrientation);
-            DetailLog("{0},BSPrim.UpdateMassProperties,mass={1},localInertia={2}", LocalID, physMass, Inertia);
+            if (IsStatic)
+            {
+                Inertia = OMV.Vector3.Zero;
+                BulletSimAPI.SetMassProps2(PhysBody.ptr, 0f, Inertia);
+                BulletSimAPI.UpdateInertiaTensor2(PhysBody.ptr);
+            }
+            else
+            {
+                if (inWorld)
+                {
+                    // Changing interesting properties doesn't change proxy and collision cache
+                    //    information. The Bullet solution is to re-add the object to the world
+                    //    after parameters are changed.
+                    BulletSimAPI.RemoveObjectFromWorld2(PhysicsScene.World.ptr, PhysBody.ptr);
+                }
+
+                Inertia = BulletSimAPI.CalculateLocalInertia2(PhysShape.ptr, physMass);
+                BulletSimAPI.SetMassProps2(PhysBody.ptr, physMass, Inertia);
+                BulletSimAPI.UpdateInertiaTensor2(PhysBody.ptr);
+
+                // center of mass is at the zero of the object
+                // DEBUG DEBUG BulletSimAPI.SetCenterOfMassByPosRot2(PhysBody.ptr, ForcePosition, ForceOrientation);
+                DetailLog("{0},BSPrim.UpdateMassProperties,mass={1},localInertia={2},inWorld={3}", LocalID, physMass, Inertia, inWorld);
+
+                if (inWorld)
+                {
+                    BulletSimAPI.AddObjectToWorld2(PhysicsScene.World.ptr, PhysBody.ptr,_position,_orientation);
+                }
+
+                // Must set gravity after it has been added to the world because, for unknown reasons,
+                //     adding the object resets the object's gravity to world gravity
+                OMV.Vector3 grav = PhysicsScene.DefaultGravity * (1f - Buoyancy);
+                BulletSimAPI.SetGravity2(PhysBody.ptr, grav);
+
+            }
         }
     }
 
@@ -714,7 +739,7 @@ public sealed class BSPrim : BSPhysObject
         Linkset.Refresh(this);
 
         DetailLog("{0},BSPrim.UpdatePhysicalParameters,taintExit,static={1},solid={2},mass={3},collide={4},cf={5:X},body={6},shape={7}",
-                        LocalID, IsStatic, IsSolid, _mass, SubscribedEvents(), CurrentCollisionFlags, PhysBody, PhysShape);
+                        LocalID, IsStatic, IsSolid, Mass, SubscribedEvents(), CurrentCollisionFlags, PhysBody, PhysShape);
     }
 
     // "Making dynamic" means changing to and from static.
@@ -737,7 +762,7 @@ public sealed class BSPrim : BSPhysObject
             BulletSimAPI.SetRestitution2(PhysBody.ptr, matAttrib.restitution);
 
             // Mass is zero which disables a bunch of physics stuff in Bullet
-            UpdatePhysicalMassProperties(0f);
+            UpdatePhysicalMassProperties(0f, false);
             // Set collision detection parameters
             if (BSParam.CcdMotionThreshold > 0f)
             {
@@ -777,7 +802,7 @@ public sealed class BSPrim : BSPhysObject
             // DEBUG DEBUG BulletSimAPI.SetCenterOfMassByPosRot2(Linkset.LinksetRoot.PhysBody.ptr, _position, _orientation);
 
             // A dynamic object has mass
-            UpdatePhysicalMassProperties(RawMass);
+            UpdatePhysicalMassProperties(RawMass, false);
 
             // Set collision detection parameters
             if (BSParam.CcdMotionThreshold > 0f)
@@ -950,13 +975,9 @@ public sealed class BSPrim : BSPhysObject
         set {
             _buoyancy = value;
             // DetailLog("{0},BSPrim.setForceBuoyancy,taint,buoy={1}", LocalID, _buoyancy);
-            // Buoyancy is faked by changing the gravity applied to the object
-            if (PhysBody.HasPhysicalBody)
-            {
-                float grav = PhysicsScene.Params.gravity * (1f - _buoyancy);
-                BulletSimAPI.SetGravity2(PhysBody.ptr, new OMV.Vector3(0f, 0f, grav));
-                ActivateIfPhysical(false);
-            }
+            // Force the recalculation of the various inertia,etc variables in the object
+            UpdatePhysicalMassProperties(_mass, true);
+            ActivateIfPhysical(false);
         }
     }
 
@@ -993,7 +1014,9 @@ public sealed class BSPrim : BSPhysObject
     public override float APIDDamping { set { return; } }
 
     public override void AddForce(OMV.Vector3 force, bool pushforce) {
-        AddForce(force, pushforce, false);
+        // Since this force is being applied in only one step, make this a force per second.
+        OMV.Vector3 addForce = force / PhysicsScene.LastTimeStep;
+        AddForce(addForce, pushforce, false);
     }
     // Applying a force just adds this to the total force on the object.
     // This added force will only last the next simulation tick.
@@ -1001,8 +1024,16 @@ public sealed class BSPrim : BSPhysObject
         // for an object, doesn't matter if force is a pushforce or not
         if (force.IsFinite())
         {
+            float magnitude = force.Length();
+            if (magnitude > 20000f)
+            {
+                // Force has a limit
+                force = force / magnitude * 20000f;
+            }
+
             OMV.Vector3 addForce = force;
             DetailLog("{0},BSPrim.addForce,call,force={1}", LocalID, addForce);
+
             PhysicsScene.TaintedObject(inTaintTime, "BSPrim.AddForce", delegate()
             {
                 // Bullet adds this central force to the total force for this tick
diff --git a/OpenSim/Region/Physics/BulletSNPlugin/BSScene.cs b/OpenSim/Region/Physics/BulletSNPlugin/BSScene.cs
index 6bcea3f0fc..1a7c34b4ff 100644
--- a/OpenSim/Region/Physics/BulletSNPlugin/BSScene.cs
+++ b/OpenSim/Region/Physics/BulletSNPlugin/BSScene.cs
@@ -74,7 +74,7 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
 
     public IMesher mesher;
     public uint WorldID { get; private set; }
-    public BulletSim World { get; private set; }
+    public BulletWorld World { get; private set; }
 
     // All the constraints that have been allocated in this instance.
     public BSConstraintCollection Constraints { get; private set; }
@@ -244,7 +244,7 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
 
         // m_log.DebugFormat("{0}: Initialize: Calling BulletSimAPI.Initialize.", LogHeader);
 
-        World = new BulletSim(0, this, BulletSimAPI.Initialize2(worldExtent, UnmanagedParams,
+        World = new BulletWorld(0, this, BulletSimAPI.Initialize2(worldExtent, UnmanagedParams,
                                         m_maxCollisionsPerFrame, ref m_collisionArray,
                                         m_maxUpdatesPerFrame,ref m_updateArray,
                                         m_DebugLogCallbackHandle));
@@ -497,13 +497,16 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
 
         InTaintTime = false; // Only used for debugging so locking is not necessary.
 
+        // The following causes the unmanaged code to output ALL the values found in ALL the objects in the world.
+        // Only enable this in a limited test world with few objects.
+        // BulletSimAPI.DumpAllInfo2(World.ptr);    // DEBUG DEBUG DEBUG
+
         // step the physical world one interval
         m_simulationStep++;
         int numSubSteps = 0;
 
         try
         {
-            //if (VehicleLoggingEnabled) DumpVehicles();  // DEBUG
             if (PhysicsLogging.Enabled) beforeTime = Util.EnvironmentTickCount();
 
             numSubSteps = BulletSimAPI.PhysicsStep2(World.ptr, timeStep, m_maxSubSteps, m_fixedTimeStep,
@@ -833,7 +836,7 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
         {
             DetailLog("{0},BSScene.AssertInTaintTime,NOT IN TAINT TIME,Region={1},Where={2}", DetailLogZero, RegionName, whereFrom);
             m_log.ErrorFormat("{0} NOT IN TAINT TIME!! Region={1}, Where={2}", LogHeader, RegionName, whereFrom);
-            Util.PrintCallStack();  // Prints the stack into the DEBUG log file.
+            Util.PrintCallStack(DetailLog);
         }
         return InTaintTime;
     }
diff --git a/OpenSim/Region/Physics/BulletSNPlugin/BSShapeCollection.cs b/OpenSim/Region/Physics/BulletSNPlugin/BSShapeCollection.cs
index 398ece095c..47fb76870e 100644
--- a/OpenSim/Region/Physics/BulletSNPlugin/BSShapeCollection.cs
+++ b/OpenSim/Region/Physics/BulletSNPlugin/BSShapeCollection.cs
@@ -98,7 +98,7 @@ public sealed class BSShapeCollection : IDisposable
     //    higher level dependencies on the shape or body. Mostly used for LinkSets to
     //    remove the physical constraints before the body is destroyed.
     // Called at taint-time!!
-    public bool GetBodyAndShape(bool forceRebuild, BulletSim sim, BSPhysObject prim,
+    public bool GetBodyAndShape(bool forceRebuild, BulletWorld sim, BSPhysObject prim,
                     ShapeDestructionCallback shapeCallback, BodyDestructionCallback bodyCallback)
     {
         PhysicsScene.AssertInTaintTime("BSShapeCollection.GetBodyAndShape");
@@ -126,7 +126,7 @@ public sealed class BSShapeCollection : IDisposable
         return ret;
     }
 
-    public bool GetBodyAndShape(bool forceRebuild, BulletSim sim, BSPhysObject prim)
+    public bool GetBodyAndShape(bool forceRebuild, BulletWorld sim, BSPhysObject prim)
     {
         return GetBodyAndShape(forceRebuild, sim, prim, null, null);
     }
@@ -918,7 +918,7 @@ public sealed class BSShapeCollection : IDisposable
     // Updates prim.BSBody with the information about the new body if one is created.
     // Returns 'true' if an object was actually created.
     // Called at taint-time.
-    private bool CreateBody(bool forceRebuild, BSPhysObject prim, BulletSim sim, BulletShape shape,
+    private bool CreateBody(bool forceRebuild, BSPhysObject prim, BulletWorld sim, BulletShape shape,
                             BodyDestructionCallback bodyCallback)
     {
         bool ret = false;
diff --git a/OpenSim/Region/Physics/BulletSNPlugin/BSTerrainHeightmap.cs b/OpenSim/Region/Physics/BulletSNPlugin/BSTerrainHeightmap.cs
index 252953ba58..ba17059da0 100644
--- a/OpenSim/Region/Physics/BulletSNPlugin/BSTerrainHeightmap.cs
+++ b/OpenSim/Region/Physics/BulletSNPlugin/BSTerrainHeightmap.cs
@@ -103,7 +103,7 @@ public sealed class BSTerrainHeightmap : BSTerrainPhys
         Vector3 centerPos;
         centerPos.X = m_mapInfo.minCoords.X + (m_mapInfo.sizeX / 2f);
         centerPos.Y = m_mapInfo.minCoords.Y + (m_mapInfo.sizeY / 2f);
-        centerPos.Z = m_mapInfo.minZ + ((m_mapInfo.maxZ - m_mapInfo.minZ) / 2f + 0.5f);
+        centerPos.Z = m_mapInfo.minZ + ((m_mapInfo.maxZ - m_mapInfo.minZ) / 2f - 0.5f);
 
         m_mapInfo.terrainBody = new BulletBody(m_mapInfo.ID,
                 BulletSimAPI.CreateBodyWithDefaultMotionState2(m_mapInfo.terrainShape.ptr,
diff --git a/OpenSim/Region/Physics/BulletSNPlugin/BSTerrainManager.cs b/OpenSim/Region/Physics/BulletSNPlugin/BSTerrainManager.cs
index dfad70ed2b..66d62f0afb 100644
--- a/OpenSim/Region/Physics/BulletSNPlugin/BSTerrainManager.cs
+++ b/OpenSim/Region/Physics/BulletSNPlugin/BSTerrainManager.cs
@@ -140,7 +140,7 @@ public sealed class BSTerrainManager : IDisposable
         m_groundPlane = new BulletBody(BSScene.GROUNDPLANE_ID,
                         BulletSimAPI.CreateBodyWithDefaultMotionState2(groundPlaneShape.ptr, BSScene.GROUNDPLANE_ID,
                                                             Vector3.Zero, Quaternion.Identity));
-        BulletSimAPI.AddObjectToWorld2(PhysicsScene.World.ptr, m_groundPlane.ptr);
+        BulletSimAPI.AddObjectToWorld2(PhysicsScene.World.ptr, m_groundPlane.ptr, Vector3.Zero, Quaternion.Identity);
         BulletSimAPI.UpdateSingleAabb2(PhysicsScene.World.ptr, m_groundPlane.ptr);
         // Ground plane does not move
         BulletSimAPI.ForceActivationState2(m_groundPlane.ptr, ActivationState.DISABLE_SIMULATION);
@@ -376,6 +376,7 @@ public sealed class BSTerrainManager : IDisposable
             DetailLog("{0},BSTerrainManager.GetTerrainHeightAtXYZ,terrainNotFound,pos={1},base={2}",
                                 BSScene.DetailLogZero, pos, terrainBaseXYZ);
         }
+
         lastHeight = ret;
         return ret;
     }
diff --git a/OpenSim/Region/Physics/BulletSNPlugin/BulletSimAPI.cs b/OpenSim/Region/Physics/BulletSNPlugin/BulletSimAPI.cs
index 6af59d69b7..93643c9f50 100644
--- a/OpenSim/Region/Physics/BulletSNPlugin/BulletSimAPI.cs
+++ b/OpenSim/Region/Physics/BulletSNPlugin/BulletSimAPI.cs
@@ -58,7 +58,6 @@ public enum ConstraintType : int
 	MAX_CONSTRAINT_TYPE
 }
 
-
 // ===============================================================================
 [StructLayout(LayoutKind.Sequential)]
 public struct ConvexHull
diff --git a/OpenSim/Region/Physics/BulletSNPlugin/BulletSimData.cs b/OpenSim/Region/Physics/BulletSNPlugin/BulletSimData.cs
index a1ed8d86c3..f509dc4092 100644
--- a/OpenSim/Region/Physics/BulletSNPlugin/BulletSimData.cs
+++ b/OpenSim/Region/Physics/BulletSNPlugin/BulletSimData.cs
@@ -35,9 +35,9 @@ namespace OpenSim.Region.Physics.BulletSNPlugin
 // These hold pointers to allocated objects in the unmanaged space.
 
 // The physics engine controller class created at initialization
-public struct BulletSim
+public struct BulletWorld
 {
-    public BulletSim(uint worldId, BSScene bss, object xx)
+    public BulletWorld(uint worldId, BSScene bss, object xx)
     {
         ptr = xx;
         worldID = worldId;

From e98e223927226602d7a050bbb92ebb2904e81562 Mon Sep 17 00:00:00 2001
From: Robert Adams <Robert.Adams@intel.com>
Date: Thu, 27 Dec 2012 06:56:36 -0800
Subject: [PATCH 05/13] BulletSim: complete applyImpulse function in
 BSCharacter (like I said I did last time).

---
 .../Physics/BulletSPlugin/BSCharacter.cs      | 25 +++++++++++++------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs b/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
index 9f0d5afdbe..cbc1772f8d 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
@@ -683,22 +683,31 @@ public sealed class BSCharacter : BSPhysObject
     public override void AddForce(OMV.Vector3 force, bool pushforce) {
         if (force.IsFinite())
         {
-            _force.X += force.X;
-            _force.Y += force.Y;
-            _force.Z += force.Z;
-            // m_log.DebugFormat("{0}: AddForce. adding={1}, newForce={2}", LogHeader, force, _force);
+            float magnitude = force.Length();
+            if (magnitude > BSParam.MaxAddForceMagnitude)
+            {
+                // Force has a limit
+                force = force / magnitude * BSParam.MaxAddForceMagnitude;
+            }
+
+            OMV.Vector3 addForce = force / PhysicsScene.LastTimeStep;
+            DetailLog("{0},BSCharacter.addForce,call,force={1}", LocalID, addForce);
+
             PhysicsScene.TaintedObject("BSCharacter.AddForce", delegate()
             {
-                DetailLog("{0},BSCharacter.setAddForce,taint,addedForce={1}", LocalID, _force);
+                // Bullet adds this central force to the total force for this tick
+                DetailLog("{0},BSCharacter.addForce,taint,force={1}", LocalID, addForce);
                 if (PhysBody.HasPhysicalBody)
-                    BulletSimAPI.SetObjectForce2(PhysBody.ptr, _force);
+                {
+                    BulletSimAPI.ApplyCentralForce2(PhysBody.ptr, addForce);
+                }
             });
         }
         else
         {
-            m_log.ErrorFormat("{0}: Got a NaN force applied to a Character", LogHeader);
+            m_log.WarnFormat("{0}: Got a NaN force applied to a character. LocalID={1}", LogHeader, LocalID);
+            return;
         }
-        //m_lastUpdateSent = false;
     }
 
     public override void AddAngularForce(OMV.Vector3 force, bool pushforce) {

From f3baed5827853c5041f042ff36cf394b1e45538f Mon Sep 17 00:00:00 2001
From: Robert Adams <Robert.Adams@intel.com>
Date: Thu, 27 Dec 2012 06:58:07 -0800
Subject: [PATCH 06/13] BulletSim: add physical parameter min/max constants in
 BSParam. I just don't like raw numbers scattered around the code.

---
 OpenSim/Region/Physics/BulletSPlugin/BSParam.cs      | 12 ++++++++++++
 OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs       |  4 ++--
 OpenSim/Region/Physics/BulletSPlugin/BSScene.cs      |  9 ---------
 .../Region/Physics/BulletSPlugin/BulletSimTODO.txt   |  1 +
 4 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs b/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs
index 7454718af2..8366cef87f 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs
@@ -89,6 +89,18 @@ public static class BSParam
     public static float PID_D { get; private set; }    // derivative
     public static float PID_P { get; private set; }    // proportional
 
+    // Various constants that come from that other virtual world that shall not be named
+    public const float MinGravityZ = -1f;
+    public const float MaxGravityZ = 28f;
+    public const float MinFriction = 0f;
+    public const float MaxFriction = 255f;
+    public const float MinDensity = 0f;
+    public const float MaxDensity = 22587f;
+    public const float MinRestitution = 0f;
+    public const float MaxRestitution = 1f;
+    public const float MaxAddForceMagnitude = 20000f;
+
+    // ===========================================================================
     public delegate void ParamUser(BSScene scene, IConfig conf, string paramName, float val);
     public delegate float ParamGet(BSScene scene);
     public delegate void ParamSet(BSScene scene, string paramName, uint localID, float val);
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
index 901341444e..c7a81e03fc 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
@@ -1025,10 +1025,10 @@ public sealed class BSPrim : BSPhysObject
         if (force.IsFinite())
         {
             float magnitude = force.Length();
-            if (magnitude > 20000f)
+            if (magnitude > BSParam.MaxAddForceMagnitude)
             {
                 // Force has a limit
-                force = force / magnitude * 20000f;
+                force = force / magnitude * BSParam.MaxAddForceMagnitude;
             }
 
             OMV.Vector3 addForce = force;
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs b/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
index b67c0ed532..a5fbf105c2 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
@@ -38,15 +38,6 @@ using Nini.Config;
 using log4net;
 using OpenMetaverse;
 
-// TODOs for BulletSim (for BSScene, BSPrim, BSCharacter and BulletSim)
-// Based on material, set density and friction
-// More efficient memory usage when passing hull information from BSPrim to BulletSim
-// Do attachments need to be handled separately? Need collision events. Do not collide with VolumeDetect
-// Implement LockAngularMotion
-// Add PID movement operations. What does ScenePresence.MoveToTarget do?
-// Check terrain size. 128 or 127?
-// Raycast
-//
 namespace OpenSim.Region.Physics.BulletSPlugin
 {
 public sealed class BSScene : PhysicsScene, IPhysicsParameters
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt b/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
index 78cc26c780..bc6dd7e2ff 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
+++ b/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
@@ -96,6 +96,7 @@ Selecting and deselecting physical objects causes CPU processing time to jump
 	put thousand physical objects, select and deselect same. CPU time will be large.
 Re-implement buoyancy as a separate force on the object rather than diddling gravity.
 	Register a pre-step event to add the force.
+More efficient memory usage when passing hull information from BSPrim to BulletSim
 
 LINKSETS
 ======================================================

From 723099067976dfa71d18182378000df144d618af Mon Sep 17 00:00:00 2001
From: Robert Adams <Robert.Adams@intel.com>
Date: Thu, 27 Dec 2012 10:09:31 -0800
Subject: [PATCH 07/13] BulletSim: fix odd code that wasn't really recomputing
 the mass of a rebuilt linkset. I was burnt by making get/set methods with
 side effects. I should know better.

---
 .../Physics/BulletSPlugin/BSLinksetCompound.cs     | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs b/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs
index d5cbf5f9e8..4e029046eb 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs
@@ -98,11 +98,12 @@ public sealed class BSLinksetCompound : BSLinkset
     // Schedule a refresh to happen after all the other taint processing.
     private void ScheduleRebuild(BSPhysObject requestor)
     {
-        DetailLog("{0},BSLinksetCompound.ScheduleRebuild,,rebuilding={1}", 
-                            requestor.LocalID, Rebuilding);
+        DetailLog("{0},BSLinksetCompound.ScheduleRebuild,,rebuilding={1},hasChildren={2}", 
+                            requestor.LocalID, Rebuilding, HasAnyChildren);
         // When rebuilding, it is possible to set properties that would normally require a rebuild.
         //    If already rebuilding, don't request another rebuild.
-        if (!Rebuilding)
+        //    If a linkset with just a root prim (simple non-linked prim) don't bother rebuilding.
+        if (!Rebuilding && HasAnyChildren)
         {
             PhysicsScene.PostTaintObject("BSLinksetCompound.ScheduleRebuild", LinksetRoot.LocalID, delegate()
             {
@@ -112,8 +113,7 @@ public sealed class BSLinksetCompound : BSLinkset
         }
     }
 
-    // The object is going dynamic (physical). Do any setup necessary
-    //     for a dynamic linkset.
+    // The object is going dynamic (physical). Do any setup necessary for a dynamic linkset.
     // Only the state of the passed object can be modified. The rest of the linkset
     //     has not yet been fully constructed.
     // Return 'true' if any properties updated on the passed object.
@@ -124,7 +124,7 @@ public sealed class BSLinksetCompound : BSLinkset
         DetailLog("{0},BSLinksetCompound.MakeDynamic,call,IsRoot={1}", child.LocalID, IsRoot(child));
         if (IsRoot(child))
         {
-            // The root is going dynamic. Make sure mass is properly set.
+            // The root is going dynamic. Rebuild the linkset so parts and mass get computed properly.
             ScheduleRebuild(LinksetRoot);
         }
         else
@@ -378,7 +378,7 @@ public sealed class BSLinksetCompound : BSLinkset
             });
 
             // With all of the linkset packed into the root prim, it has the mass of everyone.
-            LinksetMass = LinksetMass;
+            LinksetMass = ComputeLinksetMass();
             LinksetRoot.UpdatePhysicalMassProperties(LinksetMass, true);
         }
         finally

From e57c0e6731bff376186ecba2530e76b697ab5887 Mon Sep 17 00:00:00 2001
From: Robert Adams <Robert.Adams@intel.com>
Date: Thu, 27 Dec 2012 13:13:35 -0800
Subject: [PATCH 08/13] BulletSim: fix buoyancy so it's properly set by a
 script when an object is selected. Update TODO list.

---
 .../BulletSPlugin/BSLinksetCompound.cs        |  2 +-
 .../Region/Physics/BulletSPlugin/BSMotors.cs  |  4 +--
 .../Region/Physics/BulletSPlugin/BSPrim.cs    | 29 ++++++++++++++++---
 .../Physics/BulletSPlugin/BulletSimTODO.txt   | 24 ++++++++++-----
 4 files changed, 44 insertions(+), 15 deletions(-)

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs b/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs
index 4e029046eb..19ce62b92f 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs
@@ -5,7 +5,7 @@
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *     * Redistributions of source code must retain the above copyright
- *       notice, this list of conditions and the following disclat simer.
+ *       notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above copyrightD
  *       notice, this list of conditions and the following disclaimer in the
  *       documentation and/or other materials provided with the distribution.
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSMotors.cs b/OpenSim/Region/Physics/BulletSPlugin/BSMotors.cs
index 9e1a9ba6e3..817a5f7e7e 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSMotors.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSMotors.cs
@@ -241,8 +241,8 @@ public class BSVMotor : BSMotor
 
     public override string ToString()
     {
-        return String.Format("<{0},curr={1},targ={2},decayTS={3},frictTS={4}>",
-            UseName, CurrentValue, TargetValue, TargetValueDecayTimeScale, FrictionTimescale);
+        return String.Format("<{0},curr={1},targ={2},lastErr={3},decayTS={4},frictTS={5}>",
+            UseName, CurrentValue, TargetValue, LastError, TargetValueDecayTimeScale, FrictionTimescale);
     }
 }
 
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
index c7a81e03fc..f804a0f716 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
@@ -94,7 +94,7 @@ public sealed class BSPrim : BSPhysObject
         _size = size;
         Scale = size;   // prims are the size the user wants them to be (different for BSCharactes).
         _orientation = rotation;
-        _buoyancy = 1f;
+        _buoyancy = 0f;
         _velocity = OMV.Vector3.Zero;
         _rotationalVelocity = OMV.Vector3.Zero;
         BaseShape = pbs;
@@ -408,12 +408,15 @@ public sealed class BSPrim : BSPhysObject
         {
             if (IsStatic)
             {
+                BulletSimAPI.SetGravity2(PhysBody.ptr, PhysicsScene.DefaultGravity);
                 Inertia = OMV.Vector3.Zero;
                 BulletSimAPI.SetMassProps2(PhysBody.ptr, 0f, Inertia);
                 BulletSimAPI.UpdateInertiaTensor2(PhysBody.ptr);
             }
             else
             {
+                OMV.Vector3 grav = ComputeGravity();
+
                 if (inWorld)
                 {
                     // Changing interesting properties doesn't change proxy and collision cache
@@ -422,13 +425,16 @@ public sealed class BSPrim : BSPhysObject
                     BulletSimAPI.RemoveObjectFromWorld2(PhysicsScene.World.ptr, PhysBody.ptr);
                 }
 
+                // The computation of mass props requires gravity to be set on the object.
+                BulletSimAPI.SetGravity2(PhysBody.ptr, grav);
+
                 Inertia = BulletSimAPI.CalculateLocalInertia2(PhysShape.ptr, physMass);
                 BulletSimAPI.SetMassProps2(PhysBody.ptr, physMass, Inertia);
                 BulletSimAPI.UpdateInertiaTensor2(PhysBody.ptr);
 
                 // center of mass is at the zero of the object
                 // DEBUG DEBUG BulletSimAPI.SetCenterOfMassByPosRot2(PhysBody.ptr, ForcePosition, ForceOrientation);
-                DetailLog("{0},BSPrim.UpdateMassProperties,mass={1},localInertia={2},inWorld={3}", LocalID, physMass, Inertia, inWorld);
+                DetailLog("{0},BSPrim.UpdateMassProperties,mass={1},localInertia={2},grav={3},inWorld={4}", LocalID, physMass, Inertia, grav, inWorld);
 
                 if (inWorld)
                 {
@@ -437,13 +443,23 @@ public sealed class BSPrim : BSPhysObject
 
                 // Must set gravity after it has been added to the world because, for unknown reasons,
                 //     adding the object resets the object's gravity to world gravity
-                OMV.Vector3 grav = PhysicsScene.DefaultGravity * (1f - Buoyancy);
                 BulletSimAPI.SetGravity2(PhysBody.ptr, grav);
 
             }
         }
     }
 
+    // Return what gravity should be set to this very moment
+    private OMV.Vector3 ComputeGravity()
+    {
+        OMV.Vector3 ret = PhysicsScene.DefaultGravity;
+
+        if (!IsStatic)
+            ret *= (1f - Buoyancy);
+
+        return ret;
+    }
+
     // Is this used?
     public override OMV.Vector3 CenterOfMass
     {
@@ -669,7 +685,7 @@ public sealed class BSPrim : BSPhysObject
                 _isPhysical = value;
                 PhysicsScene.TaintedObject("BSPrim.setIsPhysical", delegate()
                 {
-                    // DetailLog("{0},setIsPhysical,taint,isPhys={1}", LocalID, _isPhysical);
+                    DetailLog("{0},setIsPhysical,taint,isPhys={1}", LocalID, _isPhysical);
                     SetObjectDynamic(true);
                     // whether phys-to-static or static-to-phys, the object is not moving.
                     ZeroMotion(true);
@@ -726,6 +742,10 @@ public sealed class BSPrim : BSPhysObject
 
         BulletSimAPI.AddObjectToWorld2(PhysicsScene.World.ptr, PhysBody.ptr);
 
+        // TODO: Fix this. Total kludge because adding object to world resets its gravity to default.
+        // Replace this when the new AddObjectToWorld function is complete.
+        BulletSimAPI.SetGravity2(PhysBody.ptr, ComputeGravity());
+
         // Rebuild its shape
         BulletSimAPI.UpdateSingleAabb2(PhysicsScene.World.ptr, PhysBody.ptr);
 
@@ -976,6 +996,7 @@ public sealed class BSPrim : BSPhysObject
             _buoyancy = value;
             // DetailLog("{0},BSPrim.setForceBuoyancy,taint,buoy={1}", LocalID, _buoyancy);
             // Force the recalculation of the various inertia,etc variables in the object
+            DetailLog("{0},BSPrim.ForceBuoyancy,buoy={1},mass={2}", LocalID, _buoyancy, _mass);
             UpdatePhysicalMassProperties(_mass, true);
             ActivateIfPhysical(false);
         }
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt b/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
index bc6dd7e2ff..a66508a3fe 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
+++ b/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
@@ -1,22 +1,21 @@
 CURRENT PRIORITIES
 =================================================
-Smooth avatar movement with motor (DONE)
-	Should motor update be all at taint-time? (Yes, DONE)
-	Fix avatar slowly sliding when standing (zero motion when stopped)
-llApplyImpulse()
-	Compare mass/movement in OS and SL. Calibrate actions.
-llSetBuoyancy()
-Boats float low in the water
+Redo BulletSimAPI to allow native C# implementation of Bullet option.
+Avatar movement
+	flying into a wall doesn't stop avatar who keeps appearing to move through the obsticle
+	walking up stairs is not calibrated correctly (stairs out of Kepler cabin)
+	avatar capsule rotation completed
 Enable vehicle border crossings (at least as poorly as ODE)
 	Terrain skirts
 	Avatar created in previous region and not new region when crossing border
 	Vehicle recreated in new sim at small Z value (offset from root value?) (DONE)
-Add material densities to the material types.
 Vehicle movement on terrain smoothness
 Vehicle script tuning/debugging
 	Avanti speed script
 	Weapon shooter script
 limitMotorUp calibration (more down?)
+Boats float low in the water
+Add material densities to the material types.
 
 CRASHES
 =================================================
@@ -243,3 +242,12 @@ Should vehicle angular/linear movement friction happen after all the components
 	What is expected by some vehicles (turning up friction to moderate speed))
 Tune terrain/object friction to be closer to SL.
 	(Resolution: added material type with friction and resolution)
+Smooth avatar movement with motor (DONE)
+	Should motor update be all at taint-time? (Yes, DONE)
+	Fix avatar slowly sliding when standing (zero motion when stopped) (DONE)
+	(Resolution: added BSVMotor for avatar starting and stopping)
+llApplyImpulse()
+	Compare mass/movement in OS and SL. Calibrate actions.	(DONE)
+	(Resolution: tested on SL and OS. AddForce scales the force for timestep)
+llSetBuoyancy()	(DONE)
+	(Resolution: Bullet resets object gravity when added to world. Moved set gravity)

From 5afab9bcfe9e163219cf6b4317a8914860e3f969 Mon Sep 17 00:00:00 2001
From: Robert Adams <Robert.Adams@intel.com>
Date: Thu, 27 Dec 2012 16:03:14 -0800
Subject: [PATCH 09/13] Add check to always push terse updates for presences
 that have new velocities of zero.

---
 OpenSim/Region/Framework/Scenes/ScenePresence.cs | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/OpenSim/Region/Framework/Scenes/ScenePresence.cs b/OpenSim/Region/Framework/Scenes/ScenePresence.cs
index 58721b096d..a60c55119a 100644
--- a/OpenSim/Region/Framework/Scenes/ScenePresence.cs
+++ b/OpenSim/Region/Framework/Scenes/ScenePresence.cs
@@ -2335,9 +2335,14 @@ namespace OpenSim.Region.Framework.Scenes
                 // storing a requested force instead of an actual traveling velocity
 
                 // Throw away duplicate or insignificant updates
-                if (!Rotation.ApproxEquals(m_lastRotation, ROTATION_TOLERANCE) ||
-                    !Velocity.ApproxEquals(m_lastVelocity, VELOCITY_TOLERANCE) ||
-                    !m_pos.ApproxEquals(m_lastPosition, POSITION_TOLERANCE))
+                if (
+                    // If the velocity has become zero, send it no matter what.
+                       (Velocity != m_lastVelocity && Velocity == Vector3.Zero)
+                    // otherwise, if things have changed reasonably, send the update
+                    || (!Rotation.ApproxEquals(m_lastRotation, ROTATION_TOLERANCE)
+                        || !Velocity.ApproxEquals(m_lastVelocity, VELOCITY_TOLERANCE)
+                        || !m_pos.ApproxEquals(m_lastPosition, POSITION_TOLERANCE)))
+
                 {
                     SendTerseUpdateToAllClients();
 

From 7a5f598399c7373bd146061b478e6d04cb204879 Mon Sep 17 00:00:00 2001
From: Robert Adams <Robert.Adams@intel.com>
Date: Thu, 27 Dec 2012 16:05:11 -0800
Subject: [PATCH 10/13] BulletSim: move logic for IsColliding, CollidingGround
 and CollidingObj from individual sub-classes and up to parent BSPhysObject
 class.

---
 .../Physics/BulletSPlugin/BSCharacter.cs      | 36 +++++++-----------
 .../Physics/BulletSPlugin/BSPhysObject.cs     | 37 ++++++++++++++++++-
 .../Region/Physics/BulletSPlugin/BSPrim.cs    | 18 ++-------
 .../Physics/BulletSPlugin/BulletSimTODO.txt   |  3 +-
 4 files changed, 55 insertions(+), 39 deletions(-)

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs b/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
index cbc1772f8d..3f7b5e1ce2 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
@@ -584,18 +584,6 @@ public sealed class BSCharacter : BSPhysObject
         get { return _throttleUpdates; }
         set { _throttleUpdates = value; }
     }
-    public override bool IsColliding {
-        get { return (CollidingStep == PhysicsScene.SimulationStep); }
-        set { _isColliding = value; }
-    }
-    public override bool CollidingGround {
-        get { return (CollidingGroundStep == PhysicsScene.SimulationStep); }
-        set { CollidingGround = value; }
-    }
-    public override bool CollidingObj {
-        get { return _collidingObj; }
-        set { _collidingObj = value; }
-    }
     public override bool FloatOnWater {
         set {
             _floatOnWater = value;
@@ -769,22 +757,26 @@ public sealed class BSCharacter : BSPhysObject
 
             OMV.Vector3 stepVelocity = _velocityMotor.Step(PhysicsScene.LastTimeStep);
 
-            // If falling, we keep the world's downward vector no matter what the other axis specify.
-            if (!Flying && !IsColliding)
-            {
-                stepVelocity.Z = entprop.Velocity.Z;
-                DetailLog("{0},BSCharacter.UpdateProperties,taint,overrideStepZWithWorldZ,stepVel={1}", LocalID, stepVelocity);
-            }
-
-            // If the user has said stop and we've stopped applying velocity correction,
-            //     the motor can be turned off. Set the velocity to zero so the zero motion is sent to the viewer.
-            if (_velocityMotor.TargetValue.ApproxEquals(OMV.Vector3.Zero, 0.01f) && _velocityMotor.ErrorIsZero)
+            // Check for cases to turn off the motor.
+            if (
+                // If the walking motor is all done, turn it off
+                (_velocityMotor.TargetValue.ApproxEquals(OMV.Vector3.Zero, 0.01f) && _velocityMotor.ErrorIsZero) )
             {
                 ZeroMotion(true);
                 stepVelocity = OMV.Vector3.Zero;
                 _velocityMotor.Enabled = false;
                 DetailLog("{0},BSCharacter.UpdateProperties,taint,disableVelocityMotor,m={1}", LocalID, _velocityMotor);
             }
+            else
+            {
+                // If the motor is not being turned off...
+                // If falling, we keep the world's downward vector no matter what the other axis specify.
+                if (!Flying && !IsColliding)
+                {
+                    stepVelocity.Z = entprop.Velocity.Z;
+                    DetailLog("{0},BSCharacter.UpdateProperties,taint,overrideStepZWithWorldZ,stepVel={1}", LocalID, stepVelocity);
+                }
+            }
 
             _velocity = stepVelocity;
             entprop.Velocity = _velocity;
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSPhysObject.cs b/OpenSim/Region/Physics/BulletSPlugin/BSPhysObject.cs
index 4bed535b72..73b57643c7 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSPhysObject.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSPhysObject.cs
@@ -182,9 +182,40 @@ public abstract class BSPhysObject : PhysicsActor
     protected long CollidingStep { get; set; }
     // The simulation step that last had a collision with the ground
     protected long CollidingGroundStep { get; set; }
+    // The simulation step that last collided with an object
+    protected long CollidingObjectStep { get; set; }
     // The collision flags we think are set in Bullet
     protected CollisionFlags CurrentCollisionFlags { get; set; }
 
+    public override bool IsColliding {
+        get { return (CollidingStep == PhysicsScene.SimulationStep); }
+        set {
+            if (value)
+                CollidingStep = PhysicsScene.SimulationStep;
+            else
+                CollidingStep = 0;
+            }
+    }
+    public override bool CollidingGround {
+        get { return (CollidingGroundStep == PhysicsScene.SimulationStep); }
+        set
+        {
+            if (value)
+                CollidingGroundStep = PhysicsScene.SimulationStep;
+            else
+                CollidingGroundStep = 0;
+        }
+    }
+    public override bool CollidingObj {
+        get { return (CollidingObjectStep == PhysicsScene.SimulationStep); }
+        set { 
+            if (value)
+                CollidingObjectStep = PhysicsScene.SimulationStep;
+            else
+                CollidingObjectStep = 0;
+        }
+    }
+
     // The collisions that have been collected this tick
     protected CollisionEventUpdate CollisionCollection;
 
@@ -196,12 +227,16 @@ public abstract class BSPhysObject : PhysicsActor
     {
         bool ret = false;
 
-        // The following lines make IsColliding() and IsCollidingGround() work
+        // The following lines make IsColliding(), CollidingGround() and CollidingObj work
         CollidingStep = PhysicsScene.SimulationStep;
         if (collidingWith <= PhysicsScene.TerrainManager.HighestTerrainID)
         {
             CollidingGroundStep = PhysicsScene.SimulationStep;
         }
+        else
+        {
+            CollidingObjectStep = PhysicsScene.SimulationStep;
+        }
 
         // prims in the same linkset cannot collide with each other
         if (collidee != null && (this.Linkset.LinksetID == collidee.Linkset.LinksetID))
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
index f804a0f716..06e4ada819 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
@@ -915,18 +915,6 @@ public sealed class BSPrim : BSPhysObject
         get { return _throttleUpdates; }
         set { _throttleUpdates = value; }
     }
-    public override bool IsColliding {
-        get { return (CollidingStep == PhysicsScene.SimulationStep); }
-        set { _isColliding = value; }
-    }
-    public override bool CollidingGround {
-        get { return (CollidingGroundStep == PhysicsScene.SimulationStep); }
-        set { _collidingGround = value; }
-    }
-    public override bool CollidingObj {
-        get { return _collidingObj; }
-        set { _collidingObj = value; }
-    }
     public bool IsPhantom {
         get {
             // SceneObjectPart removes phantom objects from the physics scene
@@ -1006,12 +994,12 @@ public sealed class BSPrim : BSPhysObject
     public override OMV.Vector3 PIDTarget {
         set { _PIDTarget = value; }
     }
-    public override bool PIDActive {
-        set { _usePID = value; }
-    }
     public override float PIDTau {
         set { _PIDTau = value; }
     }
+    public override bool PIDActive {
+        set { _usePID = value; }
+    }
 
     // Used for llSetHoverHeight and maybe vehicle height
     // Hover Height will override MoveTo target's Z
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt b/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
index a66508a3fe..16131cdf68 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
+++ b/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
@@ -2,9 +2,10 @@ CURRENT PRIORITIES
 =================================================
 Redo BulletSimAPI to allow native C# implementation of Bullet option.
 Avatar movement
-	flying into a wall doesn't stop avatar who keeps appearing to move through the obsticle
+	flying into a wall doesn't stop avatar who keeps appearing to move through the obstacle
 	walking up stairs is not calibrated correctly (stairs out of Kepler cabin)
 	avatar capsule rotation completed
+llMoveToTarget
 Enable vehicle border crossings (at least as poorly as ODE)
 	Terrain skirts
 	Avatar created in previous region and not new region when crossing border

From c1e7539c77480b839d513dbb7db74aa8f260eba0 Mon Sep 17 00:00:00 2001
From: Robert Adams <Robert.Adams@intel.com>
Date: Thu, 27 Dec 2012 18:19:25 -0800
Subject: [PATCH 11/13] BulletSim: Parameterize nominal frame rate (55) and add
 parameters to dynamially turn on/off detailed, unmanaged data dumping of
 prims and vehicles.

---
 OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs |  6 ++++++
 OpenSim/Region/Physics/BulletSPlugin/BSParam.cs    |  5 +++++
 OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs     |  4 ++--
 OpenSim/Region/Physics/BulletSPlugin/BSScene.cs    | 11 ++++++++---
 4 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs b/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
index a8edd2305b..0bdfbe300f 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
@@ -822,6 +822,9 @@ namespace OpenSim.Region.Physics.BulletSPlugin
         {
             if (!IsActive) return;
 
+            if (PhysicsScene.VehiclePhysicalLoggingEnabled)
+                BulletSimAPI.DumpRigidBody2(PhysicsScene.World.ptr, Prim.PhysBody.ptr);
+
             ForgetKnownVehicleProperties();
 
             MoveLinear(pTimestep);
@@ -836,6 +839,9 @@ namespace OpenSim.Region.Physics.BulletSPlugin
             //      for the physics engine to note the changes so an UpdateProperties event will happen.
             PushKnownChanged();
 
+            if (PhysicsScene.VehiclePhysicalLoggingEnabled)
+                BulletSimAPI.DumpRigidBody2(PhysicsScene.World.ptr, Prim.PhysBody.ptr);
+
             VDetailLog("{0},BSDynamics.Step,done,pos={1},force={2},velocity={3},angvel={4}",
                     Prim.LocalID, VehiclePosition, Prim.Force, VehicleVelocity, VehicleRotationalVelocity);
         }
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs b/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs
index 8366cef87f..f8f24bdf76 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs
@@ -212,6 +212,11 @@ public static class BSParam
             (s,cf,p,v) => { s.m_fixedTimeStep = cf.GetFloat(p, v); },
             (s) => { return (float)s.m_fixedTimeStep; },
             (s,p,l,v) => { s.m_fixedTimeStep = v; } ),
+        new ParameterDefn("NominalFrameRate", "The base frame rate we claim",
+            55f,
+            (s,cf,p,v) => { s.NominalFrameRate = cf.GetInt(p, (int)v); },
+            (s) => { return (float)s.NominalFrameRate; },
+            (s,p,l,v) => { s.NominalFrameRate = (int)v; } ),
         new ParameterDefn("MaxCollisionsPerFrame", "Max collisions returned at end of each frame",
             2048f,
             (s,cf,p,v) => { s.m_maxCollisionsPerFrame = cf.GetInt(p, (int)v); },
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
index 06e4ada819..2d429c46e2 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
@@ -758,8 +758,8 @@ public sealed class BSPrim : BSPhysObject
         // For compound based linksets, this enables and disables interactions of the children.
         Linkset.Refresh(this);
 
-        DetailLog("{0},BSPrim.UpdatePhysicalParameters,taintExit,static={1},solid={2},mass={3},collide={4},cf={5:X},body={6},shape={7}",
-                        LocalID, IsStatic, IsSolid, Mass, SubscribedEvents(), CurrentCollisionFlags, PhysBody, PhysShape);
+        DetailLog("{0},BSPrim.UpdatePhysicalParameters,taintExit,static={1},solid={2},mass={3},collide={4},cf={5:X},cType={6},body={7},shape={8}",
+                        LocalID, IsStatic, IsSolid, Mass, SubscribedEvents(), CurrentCollisionFlags, PhysBody.collisionType, PhysBody, PhysShape);
     }
 
     // "Making dynamic" means changing to and from static.
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs b/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
index a5fbf105c2..8edcd20b81 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
@@ -74,6 +74,7 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
     internal int m_maxSubSteps;
     internal float m_fixedTimeStep;
     internal long m_simulationStep = 0;
+    internal float NominalFrameRate { get; set; }
     public long SimulationStep { get { return m_simulationStep; } }
     internal int m_taintsToProcessPerStep;
     internal float LastTimeStep { get; private set; }
@@ -162,6 +163,7 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
     private string m_physicsLoggingPrefix;
     private int m_physicsLoggingFileMinutes;
     private bool m_physicsLoggingDoFlush;
+    private bool m_physicsPhysicalDumpEnabled;
     // 'true' of the vehicle code is to log lots of details
     public bool VehicleLoggingEnabled { get; private set; }
     public bool VehiclePhysicalLoggingEnabled { get; private set; }
@@ -272,6 +274,7 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
                 m_physicsLoggingPrefix = pConfig.GetString("PhysicsLoggingPrefix", "physics-%REGIONNAME%-");
                 m_physicsLoggingFileMinutes = pConfig.GetInt("PhysicsLoggingFileMinutes", 5);
                 m_physicsLoggingDoFlush = pConfig.GetBoolean("PhysicsLoggingDoFlush", false);
+                m_physicsPhysicalDumpEnabled = pConfig.GetBoolean("PhysicsPhysicalDumpEnabled", false);
                 // Very detailed logging for vehicle debugging
                 VehicleLoggingEnabled = pConfig.GetBoolean("VehicleLoggingEnabled", false);
                 VehiclePhysicalLoggingEnabled = pConfig.GetBoolean("VehiclePhysicalLoggingEnabled", false);
@@ -488,7 +491,8 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
 
         // The following causes the unmanaged code to output ALL the values found in ALL the objects in the world.
         // Only enable this in a limited test world with few objects.
-        // BulletSimAPI.DumpAllInfo2(World.ptr);    // DEBUG DEBUG DEBUG
+        if (m_physicsPhysicalDumpEnabled)
+            BulletSimAPI.DumpAllInfo2(World.ptr);
 
         // step the physical world one interval
         m_simulationStep++;
@@ -587,12 +591,13 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
 
         // The following causes the unmanaged code to output ALL the values found in ALL the objects in the world.
         // Only enable this in a limited test world with few objects.
-        // BulletSimAPI.DumpAllInfo2(World.ptr);    // DEBUG DEBUG DEBUG
+        if (m_physicsPhysicalDumpEnabled)
+            BulletSimAPI.DumpAllInfo2(World.ptr);
 
         // The physics engine returns the number of milliseconds it simulated this call.
         // These are summed and normalized to one second and divided by 1000 to give the reported physics FPS.
         // Multiply by 55 to give a nominal frame rate of 55.
-        return (float)numSubSteps * m_fixedTimeStep * 1000f * 55f;
+        return (float)numSubSteps * m_fixedTimeStep * 1000f * NominalFrameRate;
     }
 
     // Something has collided

From 422f0fd6ec6e30c5200dbf81875c64223002f9c7 Mon Sep 17 00:00:00 2001
From: Robert Adams <Robert.Adams@intel.com>
Date: Thu, 27 Dec 2012 22:02:38 -0800
Subject: [PATCH 12/13] BulletSim: fix physical object not interacting with
 static objects. Another instance of the underlying Bullet doing, ah, helpful
 things when items are added to the world.

---
 .../Region/Physics/BulletSPlugin/BSPrim.cs    | 33 ++++++++++++++-----
 1 file changed, 24 insertions(+), 9 deletions(-)

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
index 2d429c46e2..5f3f0d13e2 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
@@ -438,7 +438,7 @@ public sealed class BSPrim : BSPhysObject
 
                 if (inWorld)
                 {
-                    BulletSimAPI.AddObjectToWorld2(PhysicsScene.World.ptr, PhysBody.ptr);
+                    AddObjectToPhysicalWorld();
                 }
 
                 // Must set gravity after it has been added to the world because, for unknown reasons,
@@ -740,18 +740,11 @@ public sealed class BSPrim : BSPhysObject
         // Make solid or not (do things bounce off or pass through this object).
         MakeSolid(IsSolid);
 
-        BulletSimAPI.AddObjectToWorld2(PhysicsScene.World.ptr, PhysBody.ptr);
-
-        // TODO: Fix this. Total kludge because adding object to world resets its gravity to default.
-        // Replace this when the new AddObjectToWorld function is complete.
-        BulletSimAPI.SetGravity2(PhysBody.ptr, ComputeGravity());
+        AddObjectToPhysicalWorld();
 
         // Rebuild its shape
         BulletSimAPI.UpdateSingleAabb2(PhysicsScene.World.ptr, PhysBody.ptr);
 
-        // Collision filter can be set only when the object is in the world
-        PhysBody.ApplyCollisionMask();
-
         // Recompute any linkset parameters.
         // When going from non-physical to physical, this re-enables the constraints that
         //     had been automatically disabled when the mass was set to zero.
@@ -900,6 +893,28 @@ public sealed class BSPrim : BSPhysObject
         }
     }
 
+    // Add me to the physical world.
+    // Object MUST NOT already be in the world.
+    // This routine exists because some assorted properties get mangled by adding to the world.
+    internal void AddObjectToPhysicalWorld()
+    {
+        if (PhysBody.HasPhysicalBody)
+        {
+            BulletSimAPI.AddObjectToWorld2(PhysicsScene.World.ptr, PhysBody.ptr);
+
+            // TODO: Fix this. Total kludge because adding object to world resets its gravity to default.
+            // Replace this when the new AddObjectToWorld function is complete.
+            BulletSimAPI.SetGravity2(PhysBody.ptr, ComputeGravity());
+
+            // Collision filter can be set only when the object is in the world
+            if (!PhysBody.ApplyCollisionMask())
+            {
+                m_log.ErrorFormat("{0} Failed setting object collision mask: id={1}", LogHeader, LocalID);
+                DetailLog("{0},BSPrim.UpdatePhysicalParameters,failedSetMaskGroup,cType={1}", LocalID, PhysBody.collisionType);
+            }
+        }
+    }
+
     // prims don't fly
     public override bool Flying {
         get { return _flying; }

From 1f6aaad0b587f1589afd7a7ca6feb8d2bbba8641 Mon Sep 17 00:00:00 2001
From: Robert Adams <Robert.Adams@intel.com>
Date: Thu, 27 Dec 2012 22:04:12 -0800
Subject: [PATCH 13/13] BulletSim: correct collision mask definition for
 linkset children. Remove unused code. Add comments and TODOs.

---
 .../Region/Physics/BulletSPlugin/BSScene.cs   |  1 +
 .../Physics/BulletSPlugin/BulletSimAPI.cs     | 24 ++++++++---------
 .../Physics/BulletSPlugin/BulletSimData.cs    | 27 +++----------------
 .../Physics/BulletSPlugin/BulletSimTODO.txt   |  1 +
 4 files changed, 18 insertions(+), 35 deletions(-)

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs b/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
index 8edcd20b81..4133107f25 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
@@ -269,6 +269,7 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
                 BSParam.SetParameterConfigurationValues(this, pConfig);
 
                 // Very detailed logging for physics debugging
+                // TODO: the boolean values can be moved to the normal parameter processing.
                 m_physicsLoggingEnabled = pConfig.GetBoolean("PhysicsLoggingEnabled", false);
                 m_physicsLoggingDir = pConfig.GetString("PhysicsLoggingDir", ".");
                 m_physicsLoggingPrefix = pConfig.GetString("PhysicsLoggingPrefix", "physics-%REGIONNAME%-");
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BulletSimAPI.cs b/OpenSim/Region/Physics/BulletSPlugin/BulletSimAPI.cs
index afe5bcad96..eb4d039c3c 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BulletSimAPI.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BulletSimAPI.cs
@@ -250,20 +250,20 @@ public enum CollisionFilterGroups : uint
     //   filter/mask definition below. This way collision interactions
     //   are more easily found and debugged.
     BNoneGroup              = 0,
-    BDefaultGroup           = 1 << 0,
-    BStaticGroup            = 1 << 1,
-    BKinematicGroup         = 1 << 2,
-    BDebrisGroup            = 1 << 3,
-    BSensorTrigger          = 1 << 4,
-    BCharacterGroup         = 1 << 5,
-    BAllGroup               = 0xFFFFFFFF,
+    BDefaultGroup           = 1 << 0,   // 0001
+    BStaticGroup            = 1 << 1,   // 0002
+    BKinematicGroup         = 1 << 2,   // 0004
+    BDebrisGroup            = 1 << 3,   // 0008
+    BSensorTrigger          = 1 << 4,   // 0010
+    BCharacterGroup         = 1 << 5,   // 0020
+    BAllGroup               = 0x000FFFFF,
     // Filter groups defined by BulletSim
-    BGroundPlaneGroup       = 1 << 10,
-    BTerrainGroup           = 1 << 11,
-    BRaycastGroup           = 1 << 12,
-    BSolidGroup             = 1 << 13,
+    BGroundPlaneGroup       = 1 << 10,  // 0400
+    BTerrainGroup           = 1 << 11,  // 0800
+    BRaycastGroup           = 1 << 12,  // 1000
+    BSolidGroup             = 1 << 13,  // 2000
     // BLinksetGroup        = xx  // a linkset proper is either static or dynamic
-    BLinksetChildGroup      = 1 << 14,
+    BLinksetChildGroup      = 1 << 14,  // 4000
 };
 
 // CFM controls the 'hardness' of the constraint. 0=fixed, 0..1=violatable. Default=0
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BulletSimData.cs b/OpenSim/Region/Physics/BulletSPlugin/BulletSimData.cs
index 36d38d4c99..5ad6746fc4 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BulletSimData.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BulletSimData.cs
@@ -72,12 +72,12 @@ public struct BulletBody
     public bool HasPhysicalBody { get { return ptr != IntPtr.Zero; } }
 
     // Apply the specificed collision mask into the physical world
-    public void ApplyCollisionMask()
+    public bool ApplyCollisionMask()
     {
         // Should assert the body has been added to the physical world.
         // (The collision masks are stored in the collision proxy cache which only exists for
         //    a collision body that is in the world.)
-        BulletSimAPI.SetCollisionGroupMask2(ptr,
+        return BulletSimAPI.SetCollisionGroupMask2(ptr,
                                 BulletSimData.CollisionTypeMasks[collisionType].group,
                                 BulletSimData.CollisionTypeMasks[collisionType].mask);
     }
@@ -207,26 +207,6 @@ public struct CollisionTypeFilterGroup
     public uint mask;
 };
 
-    /* NOTE: old definitions kept for reference. Delete when things are working.
-    // The collsion filters and masked are defined in one place -- don't want them scattered
-    AvatarGroup             = BCharacterGroup,
-    AvatarMask              = BAllGroup,
-    ObjectGroup             = BSolidGroup,
-    ObjectMask              = BAllGroup,
-    StaticObjectGroup       = BStaticGroup,
-    StaticObjectMask        = AvatarGroup | ObjectGroup,    // static things don't interact with much
-    LinksetGroup            = BLinksetGroup,
-    LinksetMask             = BAllGroup,
-    LinksetChildGroup       = BLinksetChildGroup,
-    LinksetChildMask        = BNoneGroup,   // Linkset children disappear from the world
-    VolumeDetectGroup       = BSensorTrigger,
-    VolumeDetectMask        = ~BSensorTrigger,
-    TerrainGroup            = BTerrainGroup,
-    TerrainMask             = BAllGroup & ~BStaticGroup,  // static objects on the ground don't collide
-    GroundPlaneGroup        = BGroundPlaneGroup,
-    GroundPlaneMask         = BAllGroup
-    */
-
 public static class BulletSimData
 {
 
@@ -269,8 +249,9 @@ public static Dictionary<CollisionType, CollisionTypeFilterGroup> CollisionTypeM
     },
     { CollisionType.LinksetChild,
                 new CollisionTypeFilterGroup(CollisionType.LinksetChild, 
-                                (uint)CollisionFilterGroups.BTerrainGroup, 
+                                (uint)CollisionFilterGroups.BLinksetChildGroup, 
                                 (uint)(CollisionFilterGroups.BNoneGroup))
+                                // (uint)(CollisionFilterGroups.BCharacterGroup | CollisionFilterGroups.BSolidGroup))
     },
 };
 
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt b/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
index 16131cdf68..f805836eaa 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
+++ b/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
@@ -194,6 +194,7 @@ Should taints check for existance or activeness of target?
 	actually gone when the taint happens. Crashes don't happen because the taint closure
 	keeps the object from being freed, but that is just an accident.
 	Possibly have and 'active' flag that is checked by the taint processor?
+Parameters for physics logging should be moved from BSScene to BSParam (at least boolean ones)
 
 THREADING
 =================================================