14 files changed, 619 insertions, 260 deletions

diff --git a/OpenSim/Region/OptionalModules/Scripting/ExtendedPhysics/ExtendedPhysics.cs b/OpenSim/Region/OptionalModules/Scripting/ExtendedPhysics/ExtendedPhysics.cs
new file mode 100755
index 0000000..6009dc5
--- /dev/null
+++ b/OpenSim/Region/OptionalModules/Scripting/ExtendedPhysics/ExtendedPhysics.cs
@@ -0,0 +1,171 @@
+/*
+ * Copyright (c) Contributors, http://opensimulator.org/
+ * See CONTRIBUTORS.TXT for a full list of copyright holders.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyrightD
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of the OpenSimulator Project nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reflection;
+using System.Text;
+
+using OpenSim.Framework;
+using OpenSim.Region.Framework;
+using OpenSim.Region.Framework.Interfaces;
+using OpenSim.Region.Framework.Scenes;
+using OpenSim.Region.CoreModules;
+
+using Mono.Addins;
+using Nini.Config;
+using log4net;
+using OpenMetaverse;
+
+namespace OpenSim.Region.OptionalModules.Scripting
+{
+[Extension(Path = "/OpenSim/RegionModules", NodeName = "RegionModule")]
+public class ExtendedPhysics : INonSharedRegionModule
+{
+    private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
+    private static string LogHeader = "[EXTENDED PHYSICS]";
+
+    private IConfig Configuration { get; set; }
+    private bool Enabled { get; set; }
+    private Scene BaseScene { get; set; }
+    private IScriptModuleComms Comms { get; set; }
+
+    #region INonSharedRegionModule
+
+    public string Name { get { return this.GetType().Name; } }
+
+    public void Initialise(IConfigSource config)
+    {
+        BaseScene = null;
+        Enabled = false;
+        Configuration = null;
+        Comms = null;
+
+        try
+        {
+            if ((Configuration = config.Configs["ExtendedPhysics"]) != null)
+            {
+                Enabled = Configuration.GetBoolean("Enabled", Enabled);
+            }
+        }
+        catch (Exception e)
+        {
+            m_log.ErrorFormat("{0} Initialization error: {0}", LogHeader, e);
+        }
+
+        m_log.InfoFormat("{0} module {1} enabled", LogHeader, (Enabled ? "is" : "is not"));
+    }
+
+    public void Close()
+    {
+        if (BaseScene != null)
+        {
+            BaseScene.EventManager.OnObjectAddedToScene -= EventManager_OnObjectAddedToScene;
+            BaseScene.EventManager.OnSceneObjectPartUpdated -= EventManager_OnSceneObjectPartUpdated;
+            BaseScene = null;
+        }
+    }
+
+    public void AddRegion(Scene scene)
+    {
+    }
+
+    public void RemoveRegion(Scene scene)
+    {
+        if (BaseScene != null && BaseScene == scene)
+        {
+            Close();
+        }
+    }
+
+    public void RegionLoaded(Scene scene)
+    {
+        if (!Enabled) return;
+
+        BaseScene = scene;
+
+        Comms = BaseScene.RequestModuleInterface<IScriptModuleComms>();
+        if (Comms == null)
+        {
+            m_log.WarnFormat("{0} ScriptModuleComms interface not defined", LogHeader);
+            Enabled = false;
+
+            return;
+        }
+ 
+        // Register as LSL functions all the [ScriptInvocation] marked methods.
+        Comms.RegisterScriptInvocations(this);
+
+        // When an object is modified, we might need to update its extended physics parameters
+        BaseScene.EventManager.OnObjectAddedToScene += EventManager_OnObjectAddedToScene;
+        BaseScene.EventManager.OnSceneObjectPartUpdated += EventManager_OnSceneObjectPartUpdated;
+
+    }
+
+    public Type ReplaceableInterface { get { return null; } }
+
+    #endregion // INonSharedRegionModule
+
+    private void EventManager_OnObjectAddedToScene(SceneObjectGroup obj)
+    {
+        throw new NotImplementedException();
+    }
+
+    // Event generated when some property of a prim changes.
+    private void EventManager_OnSceneObjectPartUpdated(SceneObjectPart sop, bool isFullUpdate)
+    {
+    }
+
+    [ScriptConstant]
+    public static int PHYS_CENTER_OF_MASS =     1 << 0;
+
+    [ScriptConstant]
+    public static int PHYS_LINKSET_TYPE_CONSTRAINT  = 1;
+    [ScriptConstant]
+    public static int PHYS_LINKSET_TYPE_COMPOUND    = 2;
+    [ScriptConstant]
+    public static int PHYS_LINKSET_TYPE_MANUAL      = 3;
+
+    [ScriptInvocation]
+    public string physGetEngineType(UUID hostID, UUID scriptID)
+    {
+        string ret = string.Empty;
+
+        if (BaseScene.PhysicsScene != null)
+        {
+            ret = BaseScene.PhysicsScene.EngineType;
+        }
+
+        return ret;
+    }
+
+    [ScriptInvocation]
+    public void physSetLinksetType(UUID hostID, UUID scriptID, int linksetType)
+    {
+    }
+}
+}
diff --git a/OpenSim/Region/OptionalModules/Scripting/JsonStore/Tests/JsonStoreScriptModuleTests.cs b/OpenSim/Region/OptionalModules/Scripting/JsonStore/Tests/JsonStoreScriptModuleTests.cs
index ca88d1a..af97ac7 100644
--- a/OpenSim/Region/OptionalModules/Scripting/JsonStore/Tests/JsonStoreScriptModuleTests.cs
+++ b/OpenSim/Region/OptionalModules/Scripting/JsonStore/Tests/JsonStoreScriptModuleTests.cs
@@ -144,8 +144,7 @@ namespace OpenSim.Region.OptionalModules.Scripting.JsonStore.Tests
 
             int dsrv = (int)InvokeOp("JsonDestroyStore", fakeStoreId);
 
-            // XXX: Current returns 'true' even though no such store existed.  Need to ask if this is best behaviour.
-            Assert.That(dsrv, Is.EqualTo(1));
+            Assert.That(dsrv, Is.EqualTo(0));
         }
 
         [Test]
@@ -211,9 +210,7 @@ namespace OpenSim.Region.OptionalModules.Scripting.JsonStore.Tests
 
             // Test remove of non-existing value
             int fakeValueRemove = (int)InvokeOp("JsonRemoveValue", storeId, "Hello");
-
-            // XXX: Is this the best response to removing a value that isn't there?
-            Assert.That(fakeValueRemove, Is.EqualTo(1));
+            Assert.That(fakeValueRemove, Is.EqualTo(0));
 
             // Test get from non-existing store
             UUID fakeStoreId = TestHelpers.ParseTail(0x500);
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSApiTemplate.cs b/OpenSim/Region/Physics/BulletSPlugin/BSApiTemplate.cs
index 5e06c1e..7ab86d2 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSApiTemplate.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSApiTemplate.cs
@@ -183,6 +183,7 @@ public struct ConfigurationParameters
         public float shouldEnableFrictionCaching;
         public float numberOfSolverIterations;
     public float useSingleSidedMeshes;
+        public float globalContactBreakingThreshold;
 
     public float physicsLoggingFrames;
 
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs b/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
index d694a6a..f781aea 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSCharacter.cs
@@ -45,7 +45,6 @@ public sealed class BSCharacter : BSPhysObject
     private bool _selected;
     private OMV.Vector3 _position;
     private float _mass;
-    private float _avatarDensity;
     private float _avatarVolume;
     private OMV.Vector3 _force;
     private OMV.Vector3 _velocity;
@@ -63,9 +62,6 @@ public sealed class BSCharacter : BSPhysObject
     private bool _kinematic;
     private float _buoyancy;
 
-    // The friction and velocity of the avatar is modified depending on whether walking or not.
-    private float _currentFriction;         // the friction currently being used (changed by setVelocity).
-
     private BSVMotor _velocityMotor;
 
     private OMV.Vector3 _PIDTarget;
@@ -86,8 +82,8 @@ public sealed class BSCharacter : BSPhysObject
         _orientation = OMV.Quaternion.Identity;
         _velocity = OMV.Vector3.Zero;
         _buoyancy = ComputeBuoyancyFromFlying(isFlying);
-        _currentFriction = BSParam.AvatarStandingFriction;
-        _avatarDensity = BSParam.AvatarDensity;
+        Friction = BSParam.AvatarStandingFriction;
+        Density = BSParam.AvatarDensity;
 
         // Old versions of ScenePresence passed only the height. If width and/or depth are zero,
         //     replace with the default values.
@@ -104,7 +100,7 @@ public sealed class BSCharacter : BSPhysObject
         SetupMovementMotor();
 
         DetailLog("{0},BSCharacter.create,call,size={1},scale={2},density={3},volume={4},mass={5}",
-                            LocalID, _size, Scale, _avatarDensity, _avatarVolume, RawMass);
+                            LocalID, _size, Scale, Density, _avatarVolume, RawMass);
 
         // do actual creation in taint time
         PhysicsScene.TaintedObject("BSCharacter.create", delegate()
@@ -140,7 +136,7 @@ public sealed class BSCharacter : BSPhysObject
         ZeroMotion(true);
         ForcePosition = _position;
 
-        // Set the velocity and compute the proper friction
+        // Set the velocity
         _velocityMotor.Reset();
         _velocityMotor.SetTarget(_velocity);
         _velocityMotor.SetCurrent(_velocity);
@@ -214,35 +210,38 @@ public sealed class BSCharacter : BSPhysObject
             _velocityMotor.Step(timeStep);
 
             // If we're not supposed to be moving, make sure things are zero.
-            if (_velocityMotor.ErrorIsZero() && _velocityMotor.TargetValue == OMV.Vector3.Zero && IsColliding)
+            if (_velocityMotor.ErrorIsZero() && _velocityMotor.TargetValue == OMV.Vector3.Zero)
             {
                 // The avatar shouldn't be moving
                 _velocityMotor.Zero();
 
-                // If we are colliding with a stationary object, presume we're standing and don't move around
-                if (!ColliderIsMoving)
+                if (IsColliding)
                 {
-                    DetailLog("{0},BSCharacter.MoveMotor,collidingWithStationary,zeroingMotion", LocalID);
-                    ZeroMotion(true /* inTaintTime */);
-                }
+                    // If we are colliding with a stationary object, presume we're standing and don't move around
+                    if (!ColliderIsMoving)
+                    {
+                        DetailLog("{0},BSCharacter.MoveMotor,collidingWithStationary,zeroingMotion", LocalID);
+                        ZeroMotion(true /* inTaintTime */);
+                    }
 
-                // Standing has more friction on the ground
-                if (_currentFriction != BSParam.AvatarStandingFriction)
-                {
-                    _currentFriction = BSParam.AvatarStandingFriction;
-                    PhysicsScene.PE.SetFriction(PhysBody, _currentFriction);
+                    // Standing has more friction on the ground
+                    if (Friction != BSParam.AvatarStandingFriction)
+                    {
+                        Friction = BSParam.AvatarStandingFriction;
+                        PhysicsScene.PE.SetFriction(PhysBody, Friction);
+                    }
                 }
-                DetailLog("{0},BSCharacter.MoveMotor,taint,stopping,target={1}", LocalID, _velocityMotor.TargetValue);
+                DetailLog("{0},BSCharacter.MoveMotor,taint,stopping,target={1},colliding={2}", LocalID, _velocityMotor.TargetValue, IsColliding);
             }
             else
             {
                 OMV.Vector3 stepVelocity = _velocityMotor.CurrentValue;
 
-                if (_currentFriction != BSParam.AvatarFriction)
+                if (Friction != BSParam.AvatarFriction)
                 {
                     // Probably starting up walking. Set friction to moving friction.
-                    _currentFriction = BSParam.AvatarFriction;
-                    PhysicsScene.PE.SetFriction(PhysBody, _currentFriction);
+                    Friction = BSParam.AvatarFriction;
+                    PhysicsScene.PE.SetFriction(PhysBody, Friction);
                 }
 
                 // If falling, we keep the world's downward vector no matter what the other axis specify.
@@ -342,7 +341,7 @@ public sealed class BSCharacter : BSPhysObject
             Scale = ComputeAvatarScale(_size);
             ComputeAvatarVolumeAndMass();
             DetailLog("{0},BSCharacter.setSize,call,size={1},scale={2},density={3},volume={4},mass={5}",
-                            LocalID, _size, Scale, _avatarDensity, _avatarVolume, RawMass);
+                            LocalID, _size, Scale, Density, _avatarVolume, RawMass);
 
             PhysicsScene.TaintedObject("BSCharacter.setSize", delegate()
             {
@@ -870,7 +869,7 @@ public sealed class BSCharacter : BSPhysObject
                         * Math.Min(Size.X, Size.Y) / 2
                         * Size.Y / 2f    // plus the volume of the capsule end caps
                         );
-        _mass = _avatarDensity * _avatarVolume;
+        _mass = Density * _avatarVolume;
     }
 
     // The physics engine says that properties have updated. Update same and inform
@@ -901,7 +900,7 @@ public sealed class BSCharacter : BSPhysObject
         CurrentEntityProperties = entprop;
 
         // Tell the linkset about value changes
-        Linkset.UpdateProperties(UpdatedProperties.EntPropUpdates, this);
+        // Linkset.UpdateProperties(UpdatedProperties.EntPropUpdates, this);
 
         // Avatars don't report their changes the usual way. Changes are checked for in the heartbeat loop.
         // base.RequestPhysicsterseUpdate();
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs b/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
index b51e9fd..41d353a 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
@@ -597,7 +597,7 @@ namespace OpenSim.Region.Physics.BulletSPlugin
             if (IsActive)
             {
                 // Remember the mass so we don't have to fetch it every step
-                m_vehicleMass = Prim.Linkset.LinksetMass;
+                m_vehicleMass = Prim.TotalMass;
 
                 // Friction affects are handled by this vehicle code
                 PhysicsScene.PE.SetFriction(Prim.PhysBody, BSParam.VehicleFriction);
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSLinkset.cs b/OpenSim/Region/Physics/BulletSPlugin/BSLinkset.cs
index 1e3e5d8..e35311f 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSLinkset.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSLinkset.cs
@@ -52,7 +52,7 @@ public abstract class BSLinkset
         Manual       = 2    // linkset tied together manually (code moves all the pieces)
     }
     // Create the correct type of linkset for this child
-    public static BSLinkset Factory(BSScene physScene, BSPhysObject parent)
+    public static BSLinkset Factory(BSScene physScene, BSPrimLinkable parent)
     {
         BSLinkset ret = null;
 
@@ -71,10 +71,14 @@ public abstract class BSLinkset
                 ret = new BSLinksetCompound(physScene, parent);
                 break;
         }
+        if (ret == null)
+        {
+            physScene.Logger.ErrorFormat("[BULLETSIM LINKSET] Factory could not create linkset. Parent name={1}, ID={2}", parent.Name, parent.LocalID);
+        }
         return ret;
     }
 
-    public BSPhysObject LinksetRoot { get; protected set; }
+    public BSPrimLinkable LinksetRoot { get; protected set; }
 
     public BSScene PhysicsScene { get; private set; }
 
@@ -82,7 +86,7 @@ public abstract class BSLinkset
     public int LinksetID { get; private set; }
 
     // The children under the root in this linkset.
-    protected HashSet<BSPhysObject> m_children;
+    protected HashSet<BSPrimLinkable> m_children;
 
     // We lock the diddling of linkset classes to prevent any badness.
     // This locks the modification of the instances of this class. Changes
@@ -91,7 +95,7 @@ public abstract class BSLinkset
 
     // Some linksets have a preferred physical shape.
     // Returns SHAPE_UNKNOWN if there is no preference. Causes the correct shape to be selected.
-    public virtual BSPhysicsShapeType PreferredPhysicalShape(BSPhysObject requestor)
+    public virtual BSPhysicsShapeType PreferredPhysicalShape(BSPrimLinkable requestor)
     {
         return BSPhysicsShapeType.SHAPE_UNKNOWN;
     }
@@ -111,7 +115,7 @@ public abstract class BSLinkset
         get { return ComputeLinksetGeometricCenter(); }
     }
 
-    protected BSLinkset(BSScene scene, BSPhysObject parent)
+    protected BSLinkset(BSScene scene, BSPrimLinkable parent)
     {
         // A simple linkset of one (no children)
         LinksetID = m_nextLinksetID++;
@@ -120,7 +124,7 @@ public abstract class BSLinkset
             m_nextLinksetID = 1;
         PhysicsScene = scene;
         LinksetRoot = parent;
-        m_children = new HashSet<BSPhysObject>();
+        m_children = new HashSet<BSPrimLinkable>();
         LinksetMass = parent.RawMass;
         Rebuilding = false;
     }
@@ -129,7 +133,7 @@ public abstract class BSLinkset
     // Parent changing should not happen so do some sanity checking.
     // We return the parent's linkset so the child can track its membership.
     // Called at runtime.
-    public BSLinkset AddMeToLinkset(BSPhysObject child)
+    public BSLinkset AddMeToLinkset(BSPrimLinkable child)
     {
         lock (m_linksetActivityLock)
         {
@@ -145,14 +149,13 @@ public abstract class BSLinkset
     // Returns a new linkset for the child which is a linkset of one (just the
     //    orphened child).
     // Called at runtime.
-    public BSLinkset RemoveMeFromLinkset(BSPhysObject child)
+    public BSLinkset RemoveMeFromLinkset(BSPrimLinkable child)
     {
         lock (m_linksetActivityLock)
         {
             if (IsRoot(child))
             {
                 // Cannot remove the root from a linkset.
-                child.PositionDisplacement = OMV.Vector3.Zero;
                 return this;
             }
             RemoveChildFromLinkset(child);
@@ -160,12 +163,11 @@ public abstract class BSLinkset
         }
 
         // The child is down to a linkset of just itself
-        child.PositionDisplacement = OMV.Vector3.Zero;
         return BSLinkset.Factory(PhysicsScene, child);
     }
 
     // Return 'true' if the passed object is the root object of this linkset
-    public bool IsRoot(BSPhysObject requestor)
+    public bool IsRoot(BSPrimLinkable requestor)
     {
         return (requestor.LocalID == LinksetRoot.LocalID);
     }
@@ -176,14 +178,14 @@ public abstract class BSLinkset
     public bool HasAnyChildren { get { return (m_children.Count > 0); } }
 
     // Return 'true' if this child is in this linkset
-    public bool HasChild(BSPhysObject child)
+    public bool HasChild(BSPrimLinkable child)
     {
         bool ret = false;
         lock (m_linksetActivityLock)
         {
             ret = m_children.Contains(child);
             /* Safer version but the above should work
-            foreach (BSPhysObject bp in m_children)
+            foreach (BSPrimLinkable bp in m_children)
             {
                 if (child.LocalID == bp.LocalID)
                 {
@@ -198,14 +200,14 @@ public abstract class BSLinkset
 
     // Perform an action on each member of the linkset including root prim.
     // Depends on the action on whether this should be done at taint time.
-    public delegate bool ForEachMemberAction(BSPhysObject obj);
+    public delegate bool ForEachMemberAction(BSPrimLinkable obj);
     public virtual bool ForEachMember(ForEachMemberAction action)
     {
         bool ret = false;
         lock (m_linksetActivityLock)
         {
             action(LinksetRoot);
-            foreach (BSPhysObject po in m_children)
+            foreach (BSPrimLinkable po in m_children)
             {
                 if (action(po))
                     break;
@@ -216,16 +218,16 @@ public abstract class BSLinkset
 
     // I am the root of a linkset and a new child is being added
     // Called while LinkActivity is locked.
-    protected abstract void AddChildToLinkset(BSPhysObject child);
+    protected abstract void AddChildToLinkset(BSPrimLinkable child);
     
     // I am the root of a linkset and one of my children is being removed.
     // Safe to call even if the child is not really in my linkset.
-    protected abstract void RemoveChildFromLinkset(BSPhysObject child);
+    protected abstract void RemoveChildFromLinkset(BSPrimLinkable child);
 
     // When physical properties are changed the linkset needs to recalculate
     //   its internal properties.
     // May be called at runtime or taint-time.
-    public virtual void Refresh(BSPhysObject requestor)
+    public virtual void Refresh(BSPrimLinkable requestor)
     {
         LinksetMass = ComputeLinksetMass();
     }
@@ -240,26 +242,26 @@ public abstract class BSLinkset
     //     has not yet been fully constructed.
     // Return 'true' if any properties updated on the passed object.
     // Called at taint-time!
-    public abstract bool MakeDynamic(BSPhysObject child);
+    public abstract bool MakeDynamic(BSPrimLinkable child);
 
     // The object is going static (non-physical). Do any setup necessary
     //     for a static linkset.
     // Return 'true' if any properties updated on the passed object.
     // Called at taint-time!
-    public abstract bool MakeStatic(BSPhysObject child);
+    public abstract bool MakeStatic(BSPrimLinkable child);
 
     // Called when a parameter update comes from the physics engine for any object
     //      of the linkset is received.
     // Passed flag is update came from physics engine (true) or the user (false).
     // Called at taint-time!!
-    public abstract void UpdateProperties(UpdatedProperties whichUpdated, BSPhysObject physObject);
+    public abstract void UpdateProperties(UpdatedProperties whichUpdated, BSPrimLinkable physObject);
 
     // Routine used when rebuilding the body of the root of the linkset
     // Destroy all the constraints have have been made to root.
     // This is called when the root body is changing.
     // Returns 'true' of something was actually removed and would need restoring
     // Called at taint-time!!
-    public abstract bool RemoveBodyDependencies(BSPrim child);
+    public abstract bool RemoveBodyDependencies(BSPrimLinkable child);
 
     // ================================================================
     protected virtual float ComputeLinksetMass()
@@ -269,7 +271,7 @@ public abstract class BSLinkset
         {
             lock (m_linksetActivityLock)
             {
-                foreach (BSPhysObject bp in m_children)
+                foreach (BSPrimLinkable bp in m_children)
                 {
                     mass += bp.RawMass;
                 }
@@ -286,7 +288,7 @@ public abstract class BSLinkset
             com = LinksetRoot.Position * LinksetRoot.RawMass;
             float totalMass = LinksetRoot.RawMass;
 
-            foreach (BSPhysObject bp in m_children)
+            foreach (BSPrimLinkable bp in m_children)
             {
                 com += bp.Position * bp.RawMass;
                 totalMass += bp.RawMass;
@@ -305,7 +307,7 @@ public abstract class BSLinkset
         {
             com = LinksetRoot.Position;
 
-            foreach (BSPhysObject bp in m_children)
+            foreach (BSPrimLinkable bp in m_children)
             {
                 com += bp.Position;
             }
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs b/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs
index 0c4db40..36bae9b 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs
@@ -52,7 +52,7 @@ sealed class BSLinksetCompoundInfo : BSLinksetInfo
         OffsetRot = r;
     }
     // 'centerDisplacement' is the distance from the root the the center-of-mass (Bullet 'zero' of the shape)
-    public BSLinksetCompoundInfo(int indx, BSPhysObject root, BSPhysObject child, OMV.Vector3 centerDisplacement)
+    public BSLinksetCompoundInfo(int indx, BSPrimLinkable root, BSPrimLinkable child, OMV.Vector3 centerDisplacement)
     {
         // Each child position and rotation is given relative to the center-of-mass.
         OMV.Quaternion invRootOrientation = OMV.Quaternion.Inverse(root.RawOrientation);
@@ -93,12 +93,12 @@ public sealed class BSLinksetCompound : BSLinkset
 {
     private static string LogHeader = "[BULLETSIM LINKSET COMPOUND]";
 
-    public BSLinksetCompound(BSScene scene, BSPhysObject parent) : base(scene, parent)
+    public BSLinksetCompound(BSScene scene, BSPrimLinkable parent) : base(scene, parent)
     {
     }
 
     // For compound implimented linksets, if there are children, use compound shape for the root.
-    public override BSPhysicsShapeType PreferredPhysicalShape(BSPhysObject requestor)
+    public override BSPhysicsShapeType PreferredPhysicalShape(BSPrimLinkable requestor)
     { 
         // Returning 'unknown' means we don't have a preference.
         BSPhysicsShapeType ret = BSPhysicsShapeType.SHAPE_UNKNOWN;
@@ -112,7 +112,7 @@ public sealed class BSLinksetCompound : BSLinkset
 
     // When physical properties are changed the linkset needs to recalculate
     //   its internal properties.
-    public override void Refresh(BSPhysObject requestor)
+    public override void Refresh(BSPrimLinkable requestor)
     {
         base.Refresh(requestor);
 
@@ -121,7 +121,7 @@ public sealed class BSLinksetCompound : BSLinkset
     }
 
     // Schedule a refresh to happen after all the other taint processing.
-    private void ScheduleRebuild(BSPhysObject requestor)
+    private void ScheduleRebuild(BSPrimLinkable requestor)
     {
         DetailLog("{0},BSLinksetCompound.ScheduleRebuild,,rebuilding={1},hasChildren={2},actuallyScheduling={3}", 
                             requestor.LocalID, Rebuilding, HasAnyChildren, (!Rebuilding && HasAnyChildren));
@@ -143,7 +143,7 @@ public sealed class BSLinksetCompound : BSLinkset
     //     has not yet been fully constructed.
     // Return 'true' if any properties updated on the passed object.
     // Called at taint-time!
-    public override bool MakeDynamic(BSPhysObject child)
+    public override bool MakeDynamic(BSPrimLinkable child)
     {
         bool ret = false;
         DetailLog("{0},BSLinksetCompound.MakeDynamic,call,IsRoot={1}", child.LocalID, IsRoot(child));
@@ -173,7 +173,7 @@ public sealed class BSLinksetCompound : BSLinkset
     // This doesn't normally happen -- OpenSim removes the objects from the physical
     //     world if it is a static linkset.
     // Called at taint-time!
-    public override bool MakeStatic(BSPhysObject child)
+    public override bool MakeStatic(BSPrimLinkable child)
     {
         bool ret = false;
         DetailLog("{0},BSLinksetCompound.MakeStatic,call,IsRoot={1}", child.LocalID, IsRoot(child));
@@ -197,7 +197,7 @@ public sealed class BSLinksetCompound : BSLinkset
 
     // 'physicalUpdate' is true if these changes came directly from the physics engine. Don't need to rebuild then.
     // Called at taint-time.
-    public override void UpdateProperties(UpdatedProperties whichUpdated, BSPhysObject updated)
+    public override void UpdateProperties(UpdatedProperties whichUpdated, BSPrimLinkable updated)
     {
         // The user moving a child around requires the rebuilding of the linkset compound shape
         // One problem is this happens when a border is crossed -- the simulator implementation
@@ -222,7 +222,7 @@ public sealed class BSLinksetCompound : BSLinkset
                 if (lsi != null)
                 {
                     // Since the child moved or rotationed, it needs a new relative position within the linkset
-                    BSLinksetCompoundInfo newLsi = new BSLinksetCompoundInfo(lsi.Index, LinksetRoot, updated, LinksetRoot.PositionDisplacement);
+                    BSLinksetCompoundInfo newLsi = new BSLinksetCompoundInfo(lsi.Index, LinksetRoot, updated, OMV.Vector3.Zero);
                     updated.LinksetInfo = newLsi;
 
                     // Find the physical instance of the child 
@@ -291,7 +291,7 @@ public sealed class BSLinksetCompound : BSLinkset
     // Since we don't keep in world relationships, do nothing unless it's a child changing.
     // Returns 'true' of something was actually removed and would need restoring
     // Called at taint-time!!
-    public override bool RemoveBodyDependencies(BSPrim child)
+    public override bool RemoveBodyDependencies(BSPrimLinkable child)
     {
         bool ret = false;
 
@@ -316,7 +316,7 @@ public sealed class BSLinksetCompound : BSLinkset
     // When the linkset is built, the child shape is added to the compound shape relative to the
     //    root shape. The linkset then moves around but this does not move the actual child
     //    prim. The child prim's location must be recomputed based on the location of the root shape.
-    private void RecomputeChildWorldPosition(BSPhysObject child, bool inTaintTime)
+    private void RecomputeChildWorldPosition(BSPrimLinkable child, bool inTaintTime)
     {
         // For the moment (20130201), disable this computation (converting the child physical addr back to
         //    a region address) until we have a good handle on center-of-mass offsets and what the physics
@@ -361,7 +361,7 @@ public sealed class BSLinksetCompound : BSLinkset
 
     // Add a new child to the linkset.
     // Called while LinkActivity is locked.
-    protected override void AddChildToLinkset(BSPhysObject child)
+    protected override void AddChildToLinkset(BSPrimLinkable child)
     {
         if (!HasChild(child))
         {
@@ -377,7 +377,7 @@ public sealed class BSLinksetCompound : BSLinkset
 
     // Remove the specified child from the linkset.
     // Safe to call even if the child is not really in the linkset.
-    protected override void RemoveChildFromLinkset(BSPhysObject child)
+    protected override void RemoveChildFromLinkset(BSPrimLinkable child)
     {
         if (m_children.Remove(child))
         {
@@ -429,7 +429,7 @@ public sealed class BSLinksetCompound : BSLinkset
             if (disableCOM)                             // DEBUG DEBUG
             {                                           // DEBUG DEBUG
                 centerOfMass = LinksetRoot.RawPosition; // DEBUG DEBUG
-                LinksetRoot.PositionDisplacement = OMV.Vector3.Zero;
+                // LinksetRoot.PositionDisplacement = OMV.Vector3.Zero;
             }                                           // DEBUG DEBUG
             else
             {
@@ -438,7 +438,7 @@ public sealed class BSLinksetCompound : BSLinkset
                 centerDisplacement = LinksetRoot.RawPosition - centerOfMass;
 
                 // Since we're displacing the center of the shape, we need to move the body in the world
-                LinksetRoot.PositionDisplacement = centerDisplacement;
+                // LinksetRoot.PositionDisplacement = centerDisplacement;
 
                 // This causes the root prim position to be set properly based on the new PositionDisplacement
                 LinksetRoot.ForcePosition = LinksetRoot.RawPosition;
@@ -453,7 +453,7 @@ public sealed class BSLinksetCompound : BSLinkset
 
             // Add a shape for each of the other children in the linkset
             int memberIndex = 1;
-            ForEachMember(delegate(BSPhysObject cPrim)
+            ForEachMember(delegate(BSPrimLinkable cPrim)
             {
                 if (!IsRoot(cPrim))
                 {
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSLinksetConstraints.cs b/OpenSim/Region/Physics/BulletSPlugin/BSLinksetConstraints.cs
index 3011465..cc814d1 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSLinksetConstraints.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSLinksetConstraints.cs
@@ -36,7 +36,7 @@ public sealed class BSLinksetConstraints : BSLinkset
 {
     // private static string LogHeader = "[BULLETSIM LINKSET CONSTRAINTS]";
 
-    public BSLinksetConstraints(BSScene scene, BSPhysObject parent) : base(scene, parent)
+    public BSLinksetConstraints(BSScene scene, BSPrimLinkable parent) : base(scene, parent)
     {
     }
 
@@ -44,7 +44,7 @@ public sealed class BSLinksetConstraints : BSLinkset
     //   its internal properties.
     // This is queued in the 'post taint' queue so the
     //   refresh will happen once after all the other taints are applied.
-    public override void Refresh(BSPhysObject requestor)
+    public override void Refresh(BSPrimLinkable requestor)
     {
         base.Refresh(requestor);
 
@@ -65,7 +65,7 @@ public sealed class BSLinksetConstraints : BSLinkset
     //     has not yet been fully constructed.
     // Return 'true' if any properties updated on the passed object.
     // Called at taint-time!
-    public override bool MakeDynamic(BSPhysObject child)
+    public override bool MakeDynamic(BSPrimLinkable child)
     {
         // What is done for each object in BSPrim is what we want.
         return false;
@@ -76,14 +76,14 @@ public sealed class BSLinksetConstraints : BSLinkset
     // This doesn't normally happen -- OpenSim removes the objects from the physical
     //     world if it is a static linkset.
     // Called at taint-time!
-    public override bool MakeStatic(BSPhysObject child)
+    public override bool MakeStatic(BSPrimLinkable child)
     {
         // What is done for each object in BSPrim is what we want.
         return false;
     }
 
     // Called at taint-time!!
-    public override void UpdateProperties(UpdatedProperties whichUpdated, BSPhysObject pObj)
+    public override void UpdateProperties(UpdatedProperties whichUpdated, BSPrimLinkable pObj)
     {
         // Nothing to do for constraints on property updates
     }
@@ -93,7 +93,7 @@ public sealed class BSLinksetConstraints : BSLinkset
     //     up to rebuild the constraints before the next simulation step.
     // Returns 'true' of something was actually removed and would need restoring
     // Called at taint-time!!
-    public override bool RemoveBodyDependencies(BSPrim child)
+    public override bool RemoveBodyDependencies(BSPrimLinkable child)
     {
         bool ret = false;
 
@@ -114,7 +114,7 @@ public sealed class BSLinksetConstraints : BSLinkset
 
     // Add a new child to the linkset.
     // Called while LinkActivity is locked.
-    protected override void AddChildToLinkset(BSPhysObject child)
+    protected override void AddChildToLinkset(BSPrimLinkable child)
     {
         if (!HasChild(child))
         {
@@ -130,12 +130,12 @@ public sealed class BSLinksetConstraints : BSLinkset
 
     // Remove the specified child from the linkset.
     // Safe to call even if the child is not really in my linkset.
-    protected override void RemoveChildFromLinkset(BSPhysObject child)
+    protected override void RemoveChildFromLinkset(BSPrimLinkable child)
     {
         if (m_children.Remove(child))
         {
-            BSPhysObject rootx = LinksetRoot; // capture the root and body as of now
-            BSPhysObject childx = child;
+            BSPrimLinkable rootx = LinksetRoot; // capture the root and body as of now
+            BSPrimLinkable childx = child;
 
             DetailLog("{0},BSLinksetConstraints.RemoveChildFromLinkset,call,rID={1},rBody={2},cID={3},cBody={4}",
                             childx.LocalID,
@@ -159,13 +159,13 @@ public sealed class BSLinksetConstraints : BSLinkset
 
     // Create a constraint between me (root of linkset) and the passed prim (the child).
     // Called at taint time!
-    private void PhysicallyLinkAChildToRoot(BSPhysObject rootPrim, BSPhysObject childPrim)
+    private void PhysicallyLinkAChildToRoot(BSPrimLinkable rootPrim, BSPrimLinkable childPrim)
     {
         // Don't build the constraint when asked. Put it off until just before the simulation step.
         Refresh(rootPrim);
     }
 
-    private BSConstraint BuildConstraint(BSPhysObject rootPrim, BSPhysObject childPrim)
+    private BSConstraint BuildConstraint(BSPrimLinkable rootPrim, BSPrimLinkable childPrim)
     {
         // Zero motion for children so they don't interpolate
         childPrim.ZeroMotion(true);
@@ -239,7 +239,7 @@ public sealed class BSLinksetConstraints : BSLinkset
     // The root and child bodies are passed in because we need to remove the constraint between
     //      the bodies that were present at unlink time.
     // Called at taint time!
-    private bool PhysicallyUnlinkAChildFromRoot(BSPhysObject rootPrim, BSPhysObject childPrim)
+    private bool PhysicallyUnlinkAChildFromRoot(BSPrimLinkable rootPrim, BSPrimLinkable childPrim)
     {
         bool ret = false;
         DetailLog("{0},BSLinksetConstraint.PhysicallyUnlinkAChildFromRoot,taint,root={1},rBody={2},child={3},cBody={4}",
@@ -261,7 +261,7 @@ public sealed class BSLinksetConstraints : BSLinkset
     // Remove linkage between myself and any possible children I might have.
     // Returns 'true' of any constraints were destroyed.
     // Called at taint time!
-    private bool PhysicallyUnlinkAllChildrenFromRoot(BSPhysObject rootPrim)
+    private bool PhysicallyUnlinkAllChildrenFromRoot(BSPrimLinkable rootPrim)
     {
         DetailLog("{0},BSLinksetConstraint.PhysicallyUnlinkAllChildren,taint", rootPrim.LocalID);
 
@@ -281,7 +281,7 @@ public sealed class BSLinksetConstraints : BSLinkset
         DetailLog("{0},BSLinksetConstraint.RecomputeLinksetConstraints,set,rBody={1},linksetMass={2}",
                             LinksetRoot.LocalID, LinksetRoot.PhysBody.AddrString, linksetMass);
 
-        foreach (BSPhysObject child in m_children)
+        foreach (BSPrimLinkable child in m_children)
         {
             // 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.
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs b/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs
index 601c78c..3e0b4bc 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs
@@ -87,6 +87,7 @@ public static class BSParam
         public static float NumberOfSolverIterations;
     public static bool UseSingleSidedMeshes { get { return UseSingleSidedMeshesF != ConfigurationParameters.numericFalse; } }
     public static float UseSingleSidedMeshesF;
+    public static float GlobalContactBreakingThreshold;
 
     // Avatar parameters
     public static float AvatarFriction { get; private set; }
@@ -424,7 +425,7 @@ public static class BSParam
             (s) => { return AvatarFriction; },
             (s,p,l,v) => { AvatarFriction = v; } ),
         new ParameterDefn("AvatarStandingFriction", "Avatar friction when standing. Changed on avatar recreation.",
-            10.0f,
+            0.95f,
             (s,cf,p,v) => { AvatarStandingFriction = cf.GetFloat(p, v); },
             (s) => { return AvatarStandingFriction; },
             (s,p,l,v) => { AvatarStandingFriction = v; } ),
@@ -570,6 +571,11 @@ public static class BSParam
             (s,cf,p,v) => { UseSingleSidedMeshesF = BSParam.NumericBool(cf.GetBoolean(p, BSParam.BoolNumeric(v))); },
             (s) => { return UseSingleSidedMeshesF; },
             (s,p,l,v) => { UseSingleSidedMeshesF = v; s.UnmanagedParams[0].useSingleSidedMeshes = v; } ),
+            new ParameterDefn("GlobalContactBreakingThreshold", "Amount of shape radius before breaking a collision contact (0 says Bullet default (0.2))",
+            0f,
+            (s,cf,p,v) => { GlobalContactBreakingThreshold = cf.GetFloat(p, v); },
+            (s) => { return GlobalContactBreakingThreshold; },
+            (s,p,l,v) => { GlobalContactBreakingThreshold = v; s.UnmanagedParams[0].globalContactBreakingThreshold = v; } ),
 
             new ParameterDefn("LinksetImplementation", "Type of linkset implementation (0=Constraint, 1=Compound, 2=Manual)",
             (float)BSLinkset.LinksetImplementation.Compound,
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSPhysObject.cs b/OpenSim/Region/Physics/BulletSPlugin/BSPhysObject.cs
index 0d8bb03..de69fa0 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSPhysObject.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSPhysObject.cs
@@ -86,10 +86,6 @@ public abstract class BSPhysObject : PhysicsActor
         PhysBody = new BulletBody(localID);
         PhysShape = new BulletShape();
 
-        // A linkset of just me
-        Linkset = BSLinkset.Factory(PhysicsScene, this);
-        PositionDisplacement = OMV.Vector3.Zero;
-
         LastAssetBuildFailed = false;
 
         // Default material type. Also sets Friction, Restitution and Density.
@@ -117,8 +113,6 @@ public abstract class BSPhysObject : PhysicsActor
     public string PhysObjectName { get; protected set; }
     public string TypeName { get; protected set; }
 
-    public BSLinkset Linkset { get; set; }
-    public BSLinksetInfo LinksetInfo { get; set; }
 
     // Return the object mass without calculating it or having side effects
     public abstract float RawMass { get; }
@@ -188,15 +182,6 @@ public abstract class BSPhysObject : PhysicsActor
     public abstract OMV.Vector3 RawPosition { get; set; }
     public abstract OMV.Vector3 ForcePosition { get; set; }
 
-    // 'Position' and 'Orientation' is what the simulator thinks the positions of the prim is.
-    // Because Bullet needs the zero coordinate to be the center of mass of the linkset,
-    //     sometimes it is necessary to displace the position the physics engine thinks
-    //     the position is. PositionDisplacement must be added and removed from the
-    //     position as the simulator position is stored and fetched from the physics
-    //     engine. Similar to OrientationDisplacement.
-    public virtual OMV.Vector3 PositionDisplacement { get; set; }
-    public virtual OMV.Quaternion OrientationDisplacement { get; set; }
-
     public abstract OMV.Quaternion RawOrientation { get; set; }
     public abstract OMV.Quaternion ForceOrientation { get; set; }
 
@@ -302,22 +287,16 @@ public abstract class BSPhysObject : PhysicsActor
             CollidingObjectStep = PhysicsScene.SimulationStep;
         }
 
-        // prims in the same linkset cannot collide with each other
-        if (collidee != null && (this.Linkset.LinksetID == collidee.Linkset.LinksetID))
-        {
-            return ret;
-        }
-
         CollisionAccumulation++;
 
         // For movement tests, remember if we are colliding with an object that is moving.
-        ColliderIsMoving = collidee != null ? collidee.RawVelocity != OMV.Vector3.Zero : false;
+        ColliderIsMoving = collidee != null ? (collidee.RawVelocity != OMV.Vector3.Zero) : false;
 
         // If someone has subscribed for collision events log the collision so it will be reported up
         if (SubscribedEvents()) {
             CollisionCollection.AddCollider(collidingWith, new ContactPoint(contactPoint, contactNormal, pentrationDepth));
-            DetailLog("{0},{1}.Collison.AddCollider,call,with={2},point={3},normal={4},depth={5}",
-                            LocalID, TypeName, collidingWith, contactPoint, contactNormal, pentrationDepth);
+            DetailLog("{0},{1}.Collison.AddCollider,call,with={2},point={3},normal={4},depth={5},colliderMoving={6}",
+                            LocalID, TypeName, collidingWith, contactPoint, contactNormal, pentrationDepth, ColliderIsMoving);
 
             ret = true;
         }
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
index 85c2627..cf7aa0f 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
@@ -39,7 +39,7 @@ namespace OpenSim.Region.Physics.BulletSPlugin
 {
 
     [Serializable]
-public sealed class BSPrim : BSPhysObject
+public class BSPrim : BSPhysObject
 {
     private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
     private static readonly string LogHeader = "[BULLETS PRIM]";
@@ -102,9 +102,6 @@ public sealed class BSPrim : BSPhysObject
 
         _mass = CalculateMass();
 
-        // Cause linkset variables to be initialized (like mass)
-        Linkset.Refresh(this);
-
         DetailLog("{0},BSPrim.constructor,call", LocalID);
         // do the actual object creation at taint time
         PhysicsScene.TaintedObject("BSPrim.create", delegate()
@@ -121,15 +118,6 @@ public sealed class BSPrim : BSPhysObject
         // m_log.DebugFormat("{0}: Destroy, id={1}", LogHeader, LocalID);
         base.Destroy();
 
-        // Undo any links between me and any other object
-        BSPhysObject parentBefore = Linkset.LinksetRoot;    // DEBUG DEBUG
-        int childrenBefore = Linkset.NumberOfChildren;      // DEBUG DEBUG
-
-        Linkset = Linkset.RemoveMeFromLinkset(this);
-
-        DetailLog("{0},BSPrim.Destroy,call,parentBefore={1},childrenBefore={2},parentAfter={3},childrenAfter={4}",
-            LocalID, parentBefore.LocalID, childrenBefore, Linkset.LinksetRoot.LocalID, Linkset.NumberOfChildren);
-
         // Undo any vehicle properties
         this.VehicleType = (int)Vehicle.TYPE_NONE;
 
@@ -166,9 +154,9 @@ public sealed class BSPrim : BSPhysObject
             ForceBodyShapeRebuild(false);
         }
     }
-    // Whatever the linkset wants is what I want.
+    // 'unknown' says to choose the best type
     public override BSPhysicsShapeType PreferredPhysicalShape
-        { get { return Linkset.PreferredPhysicalShape(this); } }
+        { get { return BSPhysicsShapeType.SHAPE_UNKNOWN; } }
 
     public override bool ForceBodyShapeRebuild(bool inTaintTime)
     {
@@ -213,33 +201,10 @@ public sealed class BSPrim : BSPhysObject
 
     // link me to the specified parent
     public override void link(PhysicsActor obj) {
-        BSPrim parent = obj as BSPrim;
-        if (parent != null)
-        {
-            BSPhysObject parentBefore = Linkset.LinksetRoot;
-            int childrenBefore = Linkset.NumberOfChildren;
-
-            Linkset = parent.Linkset.AddMeToLinkset(this);
-
-            DetailLog("{0},BSPrim.link,call,parentBefore={1}, childrenBefore=={2}, parentAfter={3}, childrenAfter={4}",
-                LocalID, parentBefore.LocalID, childrenBefore, Linkset.LinksetRoot.LocalID, Linkset.NumberOfChildren);
-        }
-        return;
     }
 
     // delink me from my linkset
     public override void delink() {
-        // TODO: decide if this parent checking needs to happen at taint time
-        // Race condition here: if link() and delink() in same simulation tick, the delink will not happen
-
-        BSPhysObject parentBefore = Linkset.LinksetRoot;
-        int childrenBefore = Linkset.NumberOfChildren;
-
-        Linkset = Linkset.RemoveMeFromLinkset(this);
-
-        DetailLog("{0},BSPrim.delink,parentBefore={1},childrenBefore={2},parentAfter={3},childrenAfter={4}, ",
-            LocalID, parentBefore.LocalID, childrenBefore, Linkset.LinksetRoot.LocalID, Linkset.NumberOfChildren);
-        return;
     }
 
     // Set motion values to zero.
@@ -287,15 +252,8 @@ public sealed class BSPrim : BSPhysObject
     }
     public override OMV.Vector3 Position {
         get {
-            /* NOTE: this refetch is not necessary. The simulator knows about linkset children
-             *    and does not fetch this position info for children. Thus this is commented out.
-            // child prims move around based on their parent. Need to get the latest location
-            if (!Linkset.IsRoot(this))
-                _position = Linkset.PositionGet(this);
-            */
-
             // don't do the GetObjectPosition for root elements because this function is called a zillion times.
-            // _position = PhysicsScene.PE.GetObjectPosition2(PhysicsScene.World, BSBody) - PositionDisplacement;
+            // _position = ForcePosition;
             return _position;
         }
         set {
@@ -313,24 +271,20 @@ public sealed class BSPrim : BSPhysObject
             {
                 DetailLog("{0},BSPrim.SetPosition,taint,pos={1},orient={2}", LocalID, _position, _orientation);
                 ForcePosition = _position;
-
-                // A linkset might need to know if a component information changed.
-                Linkset.UpdateProperties(UpdatedProperties.Position, this);
-
             });
         }
     }
 
     public override OMV.Vector3 ForcePosition {
         get {
-            _position = PhysicsScene.PE.GetPosition(PhysBody) - PositionDisplacement;
+            _position = PhysicsScene.PE.GetPosition(PhysBody);
             return _position;
         }
         set {
             _position = value;
             if (PhysBody.HasPhysicalBody)
             {
-                PhysicsScene.PE.SetTranslation(PhysBody, _position + PositionDisplacement, _orientation);
+                PhysicsScene.PE.SetTranslation(PhysBody, _position, _orientation);
                 ActivateIfPhysical(false);
             }
         }
@@ -398,12 +352,13 @@ public sealed class BSPrim : BSPhysObject
         // If the simulator cares about the mass of the linkset, it will sum it itself.
     public override float Mass
     {
-        get
-        {
-            return _mass;
-        }
+        get { return _mass; }
+    }
+    // TotalMass returns the mass of the large object the prim may be in (overridden by linkset code)
+    public virtual float TotalMass
+    {
+        get { return _mass; }
     }
-
     // used when we only want this prim's mass and not the linkset thing
     public override float RawMass { 
         get { return _mass; }
@@ -467,13 +422,13 @@ public sealed class BSPrim : BSPhysObject
     // Is this used?
     public override OMV.Vector3 CenterOfMass
     {
-        get { return Linkset.CenterOfMass; }
+        get { return RawPosition; }
     }
 
     // Is this used?
     public override OMV.Vector3 GeometricCenter
     {
-        get { return Linkset.GeometricCenter; }
+        get { return RawPosition; }
     }
 
     public override OMV.Vector3 Force {
@@ -721,14 +676,6 @@ public sealed class BSPrim : BSPhysObject
     }
     public override OMV.Quaternion Orientation {
         get {
-            /* NOTE: this refetch is not necessary. The simulator knows about linkset children
-             *    and does not fetch this position info for children. Thus this is commented out.
-            // Children move around because tied to parent. Get a fresh value.
-            if (!Linkset.IsRoot(this))
-            {
-                _orientation = Linkset.OrientationGet(this);
-            }
-             */
             return _orientation;
         }
         set {
@@ -739,10 +686,6 @@ public sealed class BSPrim : BSPhysObject
             PhysicsScene.TaintedObject("BSPrim.setOrientation", delegate()
             {
                 ForceOrientation = _orientation;
-
-                // A linkset might need to know if a component information changed.
-                Linkset.UpdateProperties(UpdatedProperties.Orientation, this);
-
             });
         }
     }
@@ -758,7 +701,7 @@ public sealed class BSPrim : BSPhysObject
         {
             _orientation = value;
             if (PhysBody.HasPhysicalBody)
-                PhysicsScene.PE.SetTranslation(PhysBody, _position + PositionDisplacement, _orientation);
+                PhysicsScene.PE.SetTranslation(PhysBody, _position, _orientation);
         }
     }
     public override int PhysicsActorType {
@@ -814,7 +757,7 @@ public sealed class BSPrim : BSPhysObject
     //     isSolid: other objects bounce off of this object
     //     isVolumeDetect: other objects pass through but can generate collisions
     //     collisionEvents: whether this object returns collision events
-    public void UpdatePhysicalParameters()
+    public virtual void UpdatePhysicalParameters()
     {
         if (!PhysBody.HasPhysicalBody)
         {
@@ -844,12 +787,6 @@ public sealed class BSPrim : BSPhysObject
         // Rebuild its shape
         PhysicsScene.PE.UpdateSingleAabb(PhysicsScene.World, PhysBody);
 
-        // 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.
-        // 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},cType={6},body={7},shape={8}",
                         LocalID, IsStatic, IsSolid, Mass, SubscribedEvents(), CurrentCollisionFlags, PhysBody.collisionType, PhysBody, PhysShape);
     }
@@ -859,7 +796,7 @@ public sealed class BSPrim : BSPhysObject
     // When dynamic, the object can fall and be pushed by others.
     // This is independent of its 'solidness' which controls what passes through
     //    this object and what interacts with it.
-    private void MakeDynamic(bool makeStatic)
+    protected virtual void MakeDynamic(bool makeStatic)
     {
         if (makeStatic)
         {
@@ -889,9 +826,6 @@ public sealed class BSPrim : BSPhysObject
 
             // This collides like a static object
             PhysBody.collisionType = CollisionType.Static;
-
-            // There can be special things needed for implementing linksets
-            Linkset.MakeStatic(this);
         }
         else
         {
@@ -908,10 +842,7 @@ public sealed class BSPrim : BSPhysObject
             // PhysicsScene.PE.ClearAllForces(BSBody);
 
             // For good measure, make sure the transform is set through to the motion state
-            PhysicsScene.PE.SetTranslation(PhysBody, _position + PositionDisplacement, _orientation);
-
-            // Center of mass is at the center of the object
-            // DEBUG DEBUG PhysicsScene.PE.SetCenterOfMassByPosRot(Linkset.LinksetRoot.PhysBody, _position, _orientation);
+            ForcePosition = _position;
 
             // A dynamic object has mass
             UpdatePhysicalMassProperties(RawMass, false);
@@ -935,9 +866,6 @@ public sealed class BSPrim : BSPhysObject
             // Force activation of the object so Bullet will act on it.
             // Must do the ForceActivationState2() to overcome the DISABLE_SIMULATION from static objects.
             PhysicsScene.PE.ForceActivationState(PhysBody, ActivationState.ACTIVE_TAG);
-
-            // There might be special things needed for implementing linksets.
-            Linkset.MakeDynamic(this);
         }
     }
 
@@ -1643,16 +1571,6 @@ public sealed class BSPrim : BSPhysObject
 
         returnMass = Density * volume;
 
-        /* Comment out code that computes the mass of the linkset. That is done in the Linkset class.
-        if (IsRootOfLinkset)
-        {
-            foreach (BSPrim prim in _childrenPrims)
-            {
-                returnMass += prim.CalculateMass();
-            }
-        }
-         */
-
         returnMass = Util.Clamp(returnMass, BSParam.MinimumObjectMass, BSParam.MaximumObjectMass);
 
         return returnMass;
@@ -1672,8 +1590,7 @@ public sealed class BSPrim : BSPhysObject
             // Called if the current prim body is about to be destroyed.
             // Remove all the physical dependencies on the old body.
             // (Maybe someday make the changing of BSShape an event to be subscribed to by BSLinkset, ...)
-            Linkset.RemoveBodyDependencies(this);
-            VehicleController.RemoveBodyDependencies(this);
+            RemoveBodyDependencies();
         });
 
         // Make sure the properties are set on the new object
@@ -1681,57 +1598,50 @@ public sealed class BSPrim : BSPhysObject
         return;
     }
 
+    protected virtual void RemoveBodyDependencies()
+    {
+        VehicleController.RemoveBodyDependencies(this);
+    }
+
     // The physics engine says that properties have updated. Update same and inform
     // the world that things have changed.
     public override void UpdateProperties(EntityProperties entprop)
     {
-        // Updates only for individual prims and for the root object of a linkset.
-        if (Linkset.IsRoot(this))
+        // A temporary kludge to suppress the rotational effects introduced on vehicles by Bullet
+        // TODO: handle physics introduced by Bullet with computed vehicle physics.
+        if (VehicleController.IsActive)
         {
-            // A temporary kludge to suppress the rotational effects introduced on vehicles by Bullet
-            // TODO: handle physics introduced by Bullet with computed vehicle physics.
-            if (VehicleController.IsActive)
-            {
-                entprop.RotationalVelocity = OMV.Vector3.Zero;
-            }
-
-            // DetailLog("{0},BSPrim.UpdateProperties,entry,entprop={1}", LocalID, entprop);   // DEBUG DEBUG
+            entprop.RotationalVelocity = OMV.Vector3.Zero;
+        }
 
-            // Undo any center-of-mass displacement that might have been done.
-            if (PositionDisplacement != OMV.Vector3.Zero)
-            {
-                // Correct for any rotation around the center-of-mass
-                // TODO!!!
-                entprop.Position -= PositionDisplacement;
-            }
+        // DetailLog("{0},BSPrim.UpdateProperties,entry,entprop={1}", LocalID, entprop);   // DEBUG DEBUG
 
-            // Assign directly to the local variables so the normal set actions do not happen
-            _position = entprop.Position;
-            _orientation = entprop.Rotation;
-            _velocity = entprop.Velocity;
-            _acceleration = entprop.Acceleration;
-            _rotationalVelocity = entprop.RotationalVelocity;
+        // Assign directly to the local variables so the normal set actions do not happen
+        _position = entprop.Position;
+        _orientation = entprop.Rotation;
+        _velocity = entprop.Velocity;
+        _acceleration = entprop.Acceleration;
+        _rotationalVelocity = entprop.RotationalVelocity;
 
-            // DetailLog("{0},BSPrim.UpdateProperties,afterAssign,entprop={1}", LocalID, entprop);   // DEBUG DEBUG
+        // DetailLog("{0},BSPrim.UpdateProperties,afterAssign,entprop={1}", LocalID, entprop);   // DEBUG DEBUG
 
-            // The sanity check can change the velocity and/or position.
-            if (PositionSanityCheck(true /* inTaintTime */ ))
-            {
-                entprop.Position = _position;
-                entprop.Velocity = _velocity;
-                entprop.RotationalVelocity = _rotationalVelocity;
-                entprop.Acceleration = _acceleration;
-            }
+        // The sanity check can change the velocity and/or position.
+        if (PositionSanityCheck(true /* inTaintTime */ ))
+        {
+            entprop.Position = _position;
+            entprop.Velocity = _velocity;
+            entprop.RotationalVelocity = _rotationalVelocity;
+            entprop.Acceleration = _acceleration;
+        }
 
-            OMV.Vector3 direction = OMV.Vector3.UnitX * _orientation;   // DEBUG DEBUG DEBUG
-            DetailLog("{0},BSPrim.UpdateProperties,call,entProp={1},dir={2}", LocalID, entprop, direction);
+        OMV.Vector3 direction = OMV.Vector3.UnitX * _orientation;   // DEBUG DEBUG DEBUG
+        DetailLog("{0},BSPrim.UpdateProperties,call,entProp={1},dir={2}", LocalID, entprop, direction);
 
-            // remember the current and last set values
-            LastEntityProperties = CurrentEntityProperties;
-            CurrentEntityProperties = entprop;
+        // remember the current and last set values
+        LastEntityProperties = CurrentEntityProperties;
+        CurrentEntityProperties = entprop;
 
-            base.RequestPhysicsterseUpdate();
-        }
+        base.RequestPhysicsterseUpdate();
             /*
         else
         {
@@ -1741,9 +1651,6 @@ public sealed class BSPrim : BSPhysObject
                     entprop.Acceleration, entprop.RotationalVelocity);
         }
              */
-
-        // The linkset implimentation might want to know about this.
-        Linkset.UpdateProperties(UpdatedProperties.EntPropUpdates, this);
     }
 }
 }
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSPrimDisplaced.cs b/OpenSim/Region/Physics/BulletSPlugin/BSPrimDisplaced.cs
new file mode 100755
index 0000000..6401308
--- /dev/null
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSPrimDisplaced.cs
@@ -0,0 +1,118 @@
+/*
+ * Copyright (c) Contributors, http://opensimulator.org/
+ * See CONTRIBUTORS.TXT for a full list of copyright holders.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of the OpenSimulator Project nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * The quotations from http://wiki.secondlife.com/wiki/Linden_Vehicle_Tutorial
+ * are Copyright (c) 2009 Linden Research, Inc and are used under their license
+ * of Creative Commons Attribution-Share Alike 3.0
+ * (http://creativecommons.org/licenses/by-sa/3.0/).
+ */
+
+using System;
+using System.Collections.Generic;
+using System.Reflection;
+using System.Runtime.InteropServices;
+using OpenMetaverse;
+using OpenSim.Framework;
+using OpenSim.Region.Physics.Manager;
+
+using OMV = OpenMetaverse;
+
+namespace OpenSim.Region.Physics.BulletSPlugin
+{
+public class BSPrimDisplaced : BSPrim
+{
+    // 'Position' and 'Orientation' is what the simulator thinks the positions of the prim is.
+    // Because Bullet needs the zero coordinate to be the center of mass of the linkset,
+    //     sometimes it is necessary to displace the position the physics engine thinks
+    //     the position is. PositionDisplacement must be added and removed from the
+    //     position as the simulator position is stored and fetched from the physics
+    //     engine. Similar to OrientationDisplacement.
+    public virtual OMV.Vector3 PositionDisplacement { get; set; }
+    public virtual OMV.Quaternion OrientationDisplacement { get; set; }
+    public virtual OMV.Vector3 CenterOfMassLocation { get; set; }
+    public virtual OMV.Vector3 GeometricCenterLocation { get; set; }
+
+    public BSPrimDisplaced(uint localID, String primName, BSScene parent_scene, OMV.Vector3 pos, OMV.Vector3 size,
+                       OMV.Quaternion rotation, PrimitiveBaseShape pbs, bool pisPhysical)
+        : base(localID, primName, parent_scene, pos, size, rotation, pbs, pisPhysical)
+    {
+        CenterOfMassLocation = RawPosition;
+        GeometricCenterLocation = RawPosition;
+    }
+
+    public override Vector3 ForcePosition
+    {
+        get
+        {
+            return base.ForcePosition;
+        }
+        set
+        {
+            base.ForcePosition = value;
+            CenterOfMassLocation = RawPosition;
+            GeometricCenterLocation = RawPosition;
+        }
+    }
+
+    public override Quaternion ForceOrientation
+    {
+        get
+        {
+            return base.ForceOrientation;
+        }
+        set
+        {
+            base.ForceOrientation = value;
+        }
+    }
+
+    // Is this used?
+    public override OMV.Vector3 CenterOfMass
+    {
+        get { return CenterOfMassLocation; }
+    }
+
+    // Is this used?
+    public override OMV.Vector3 GeometricCenter
+    {
+        get { return GeometricCenterLocation; }
+    }
+
+
+    public override void UpdateProperties(EntityProperties entprop)
+    {
+        // Undo any center-of-mass displacement that might have been done.
+        if (PositionDisplacement != OMV.Vector3.Zero)
+        {
+            // Correct for any rotation around the center-of-mass
+            // TODO!!!
+            entprop.Position -= PositionDisplacement;
+        }
+
+        base.UpdateProperties(entprop);
+    }
+}
+}
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSPrimLinkable.cs b/OpenSim/Region/Physics/BulletSPlugin/BSPrimLinkable.cs
new file mode 100755
index 0000000..9898562
--- /dev/null
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSPrimLinkable.cs
@@ -0,0 +1,179 @@
+/*
+ * Copyright (c) Contributors, http://opensimulator.org/
+ * See CONTRIBUTORS.TXT for a full list of copyright holders.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyrightD
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of the OpenSimulator Project nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+using OpenSim.Framework;
+
+using OMV = OpenMetaverse;
+
+namespace OpenSim.Region.Physics.BulletSPlugin
+{
+public class BSPrimLinkable : BSPrimDisplaced
+{
+    public BSLinkset Linkset { get; set; }
+    public BSLinksetInfo LinksetInfo { get; set; }
+
+    public BSPrimLinkable(uint localID, String primName, BSScene parent_scene, OMV.Vector3 pos, OMV.Vector3 size,
+                       OMV.Quaternion rotation, PrimitiveBaseShape pbs, bool pisPhysical)
+        : base(localID, primName, parent_scene, pos, size, rotation, pbs, pisPhysical)
+    {
+        Linkset = BSLinkset.Factory(PhysicsScene, this);
+
+        PhysicsScene.TaintedObject("BSPrimLinksetCompound.Refresh", delegate()
+        {
+            Linkset.Refresh(this);
+        });
+    }
+
+    public override void Destroy()
+    {
+        Linkset = Linkset.RemoveMeFromLinkset(this);
+        base.Destroy();
+    }
+
+    public override BSPhysicsShapeType PreferredPhysicalShape
+        { get { return Linkset.PreferredPhysicalShape(this); } }
+
+    public override void link(Manager.PhysicsActor obj)
+    {
+        BSPrimLinkable parent = obj as BSPrimLinkable;
+        if (parent != null)
+        {
+            BSPhysObject parentBefore = Linkset.LinksetRoot;
+            int childrenBefore = Linkset.NumberOfChildren;
+
+            Linkset = parent.Linkset.AddMeToLinkset(this);
+
+            DetailLog("{0},BSPrimLinkset.link,call,parentBefore={1}, childrenBefore=={2}, parentAfter={3}, childrenAfter={4}",
+                LocalID, parentBefore.LocalID, childrenBefore, Linkset.LinksetRoot.LocalID, Linkset.NumberOfChildren);
+        }
+        return;
+    }
+
+    public override void delink()
+    {
+        // TODO: decide if this parent checking needs to happen at taint time
+        // Race condition here: if link() and delink() in same simulation tick, the delink will not happen
+
+        BSPhysObject parentBefore = Linkset.LinksetRoot;
+        int childrenBefore = Linkset.NumberOfChildren;
+
+        Linkset = Linkset.RemoveMeFromLinkset(this);
+
+        DetailLog("{0},BSPrimLinkset.delink,parentBefore={1},childrenBefore={2},parentAfter={3},childrenAfter={4}, ",
+            LocalID, parentBefore.LocalID, childrenBefore, Linkset.LinksetRoot.LocalID, Linkset.NumberOfChildren);
+        return;
+        base.delink();
+    }
+
+    // When simulator changes position, this might be moving a child of the linkset.
+    public override OMV.Vector3 Position
+    {
+        get { return base.Position; }
+        set
+        {
+            base.Position = value;
+            PhysicsScene.TaintedObject("BSPrimLinkset.setPosition", delegate()
+            {
+                Linkset.UpdateProperties(UpdatedProperties.Position, this);
+            });
+        }
+    }
+
+    // When simulator changes orientation, this might be moving a child of the linkset.
+    public override OMV.Quaternion Orientation
+    {
+        get { return base.Orientation; }
+        set
+        {
+            base.Orientation = value;
+            PhysicsScene.TaintedObject("BSPrimLinkset.setOrientation", delegate()
+            {
+                Linkset.UpdateProperties(UpdatedProperties.Orientation, this);
+            });
+        }
+    }
+
+    public override float TotalMass
+    {
+        get { return Linkset.LinksetMass; }
+    }
+
+    public override void UpdatePhysicalParameters()
+    {
+        base.UpdatePhysicalParameters();
+        // 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.
+        // For compound based linksets, this enables and disables interactions of the children.
+        Linkset.Refresh(this);
+    }
+
+    protected override void MakeDynamic(bool makeStatic)
+    {
+        base.MakeDynamic(makeStatic);
+        if (makeStatic)
+            Linkset.MakeStatic(this);
+        else
+            Linkset.MakeDynamic(this);
+    }
+
+    // Body is being taken apart. Remove physical dependencies and schedule a rebuild.
+    protected override void RemoveBodyDependencies()
+    {
+        Linkset.RemoveBodyDependencies(this);
+        base.RemoveBodyDependencies();
+    }
+
+    public override void UpdateProperties(EntityProperties entprop)
+    {
+        if (Linkset.IsRoot(this))
+        {
+            // Properties are only updated for the roots of a linkset.
+            // TODO: this will have to change when linksets are articulated.
+            base.UpdateProperties(entprop);
+        }
+        // The linkset might like to know about changing locations
+        Linkset.UpdateProperties(UpdatedProperties.EntPropUpdates, this);
+    }
+
+    public override bool Collide(uint collidingWith, BSPhysObject collidee,
+                    OMV.Vector3 contactPoint, OMV.Vector3 contactNormal, float pentrationDepth)
+    {
+        // prims in the same linkset cannot collide with each other
+        BSPrimLinkable convCollidee = collidee as BSPrimLinkable;
+        if (convCollidee != null && (this.Linkset.LinksetID == convCollidee.Linkset.LinksetID))
+        {
+            return false;
+        }
+        return base.Collide(collidingWith, collidee, contactPoint, contactNormal, pentrationDepth);
+    }
+}
+}
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs b/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
index f8a0c1e..05722b8 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
@@ -434,7 +434,7 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
     {
         if (!m_initialized) return;
 
-        BSPrim bsprim = prim as BSPrim;
+        BSPhysObject bsprim = prim as BSPhysObject;
         if (bsprim != null)
         {
             DetailLog("{0},RemovePrim,call", bsprim.LocalID);
@@ -463,9 +463,9 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
 
         if (!m_initialized) return null;
 
-        DetailLog("{0},AddPrimShape,call", localID);
+        DetailLog("{0},BSScene.AddPrimShape,call", localID);
 
-        BSPrim prim = new BSPrim(localID, primName, this, position, size, rotation, pbs, isPhysical);
+        BSPhysObject prim = new BSPrimLinkable(localID, primName, this, position, size, rotation, pbs, isPhysical);
         lock (PhysObjects) PhysObjects.Add(localID, prim);
         return prim;
     }