* Initial commit of BulletSimN (BulletSNPlugin). Purely C# implementation of BulletSim. This is designed to be /as close as possible/ to the BulletSim plugin while still being entirely in the managed space to make keeping it up to date easy as possible (no thinking work). This implementation is /slower/ then the c++ version just because it's fully managed, so it's not appropriate for huge sims, but it will run small ones OK. At the moment, it supports all known features of BulletSim. Think of it like.. POS but everything works. To use this plugin, set the physics plugin to BulletSimN.

1 files changed, 1015 insertions, 0 deletions

diff --git a/OpenSim/Region/Physics/BulletSNPlugin/BSShapeCollection.cs b/OpenSim/Region/Physics/BulletSNPlugin/BSShapeCollection.cs
new file mode 100644
index 0000000..398ece0
--- /dev/null
+++ b/OpenSim/Region/Physics/BulletSNPlugin/BSShapeCollection.cs
@@ -0,0 +1,1015 @@
+/*
+ * Copyright (c) Contributors, http://opensimulator.org/
+ * See CONTRIBUTORS.TXT for a full list of copyright holders.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyrightD
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of the OpenSimulator Project nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+using System;
+using System.Collections.Generic;
+using System.Text;
+using OMV = OpenMetaverse;
+using OpenSim.Framework;
+using OpenSim.Region.Physics.Manager;
+using OpenSim.Region.Physics.ConvexDecompositionDotNet;
+
+namespace OpenSim.Region.Physics.BulletSNPlugin
+{
+public sealed class BSShapeCollection : IDisposable
+{
+    private static string LogHeader = "[BULLETSIM SHAPE COLLECTION]";
+
+    private BSScene PhysicsScene { get; set; }
+
+    private Object m_collectionActivityLock = new Object();
+
+    // Description of a Mesh
+    private struct MeshDesc
+    {
+        public Object ptr;
+        public int referenceCount;
+        public DateTime lastReferenced;
+        public UInt64 shapeKey;
+    }
+
+    // Description of a hull.
+    // Meshes and hulls have the same shape hash key but we only need hulls for efficient collision calculations.
+    private struct HullDesc
+    {
+        public Object ptr;
+        public int referenceCount;
+        public DateTime lastReferenced;
+        public UInt64 shapeKey;
+    }
+
+    // The sharable set of meshes and hulls. Indexed by their shape hash.
+    private Dictionary<System.UInt64, MeshDesc> Meshes = new Dictionary<System.UInt64, MeshDesc>();
+    private Dictionary<System.UInt64, HullDesc> Hulls = new Dictionary<System.UInt64, HullDesc>();
+
+    private bool DDetail = false;
+
+    public BSShapeCollection(BSScene physScene)
+    {
+        PhysicsScene = physScene;
+        // Set the next to 'true' for very detailed shape update detailed logging (detailed details?)
+        // While detailed debugging is still active, this is better than commenting out all the
+        //     DetailLog statements. When debugging slows down, this and the protected logging
+        //     statements can be commented/removed.
+        DDetail = true;
+    }
+
+    public void Dispose()
+    {
+        // TODO!!!!!!!!!
+    }
+
+    // Callbacks called just before either the body or shape is destroyed.
+    // Mostly used for changing bodies out from under Linksets.
+    // Useful for other cases where parameters need saving.
+    // Passing 'null' says no callback.
+    public delegate void ShapeDestructionCallback(BulletShape shape);
+    public delegate void BodyDestructionCallback(BulletBody body);
+
+    // Called to update/change the body and shape for an object.
+    // First checks the shape and updates that if necessary then makes
+    //    sure the body is of the right type.
+    // Return 'true' if either the body or the shape changed.
+    // 'shapeCallback' and 'bodyCallback' are, if non-null, functions called just before
+    //    the current shape or body is destroyed. This allows the caller to remove any
+    //    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,
+                    ShapeDestructionCallback shapeCallback, BodyDestructionCallback bodyCallback)
+    {
+        PhysicsScene.AssertInTaintTime("BSShapeCollection.GetBodyAndShape");
+
+        bool ret = false;
+
+        // This lock could probably be pushed down lower but building shouldn't take long
+        lock (m_collectionActivityLock)
+        {
+            // Do we have the correct geometry for this type of object?
+            // Updates prim.BSShape with information/pointers to shape.
+            // Returns 'true' of BSShape is changed to a new shape.
+            bool newGeom = CreateGeom(forceRebuild, prim, shapeCallback);
+            // If we had to select a new shape geometry for the object,
+            //    rebuild the body around it.
+            // Updates prim.BSBody with information/pointers to requested body
+            // Returns 'true' if BSBody was changed.
+            bool newBody = CreateBody((newGeom || forceRebuild), prim, PhysicsScene.World,
+                                    prim.PhysShape, bodyCallback);
+            ret = newGeom || newBody;
+        }
+        DetailLog("{0},BSShapeCollection.GetBodyAndShape,taintExit,force={1},ret={2},body={3},shape={4}",
+                                prim.LocalID, forceRebuild, ret, prim.PhysBody, prim.PhysShape);
+
+        return ret;
+    }
+
+    public bool GetBodyAndShape(bool forceRebuild, BulletSim sim, BSPhysObject prim)
+    {
+        return GetBodyAndShape(forceRebuild, sim, prim, null, null);
+    }
+
+    // Track another user of a body.
+    // We presume the caller has allocated the body.
+    // Bodies only have one user so the body is just put into the world if not already there.
+    public void ReferenceBody(BulletBody body, bool inTaintTime)
+    {
+        lock (m_collectionActivityLock)
+        {
+            if (DDetail) DetailLog("{0},BSShapeCollection.ReferenceBody,newBody,body={1}", body.ID, body);
+            PhysicsScene.TaintedObject(inTaintTime, "BSShapeCollection.ReferenceBody", delegate()
+            {
+                if (!BulletSimAPI.IsInWorld2(PhysicsScene.World.ptr, body.ptr))
+                {
+                    BulletSimAPI.AddObjectToWorld2(PhysicsScene.World.ptr, body.ptr);
+                    if (DDetail) DetailLog("{0},BSShapeCollection.ReferenceBody,addedToWorld,ref={1}", body.ID, body);
+                }
+            });
+        }
+    }
+
+    // Release the usage of a body.
+    // Called when releasing use of a BSBody. BSShape is handled separately.
+    public void DereferenceBody(BulletBody body, bool inTaintTime, BodyDestructionCallback bodyCallback )
+    {
+        if (!body.HasPhysicalBody)
+            return;
+
+        lock (m_collectionActivityLock)
+        {
+            PhysicsScene.TaintedObject(inTaintTime, "BSShapeCollection.DereferenceBody", delegate()
+            {
+                if (DDetail) DetailLog("{0},BSShapeCollection.DereferenceBody,DestroyingBody,body={1},inTaintTime={2}",
+                                            body.ID, body, inTaintTime);
+                // If the caller needs to know the old body is going away, pass the event up.
+                if (bodyCallback != null) bodyCallback(body);
+
+                if (BulletSimAPI.IsInWorld2(PhysicsScene.World.ptr, body.ptr))
+                {
+                    BulletSimAPI.RemoveObjectFromWorld2(PhysicsScene.World.ptr, body.ptr);
+                    if (DDetail) DetailLog("{0},BSShapeCollection.DereferenceBody,removingFromWorld. Body={1}", body.ID, body);
+                }
+
+                // Zero any reference to the shape so it is not freed when the body is deleted.
+                BulletSimAPI.SetCollisionShape2(PhysicsScene.World.ptr, body.ptr, null);
+                BulletSimAPI.DestroyObject2(PhysicsScene.World.ptr, body.ptr);
+            });
+        }
+    }
+
+    // Track the datastructures and use count for a shape.
+    // When creating a hull, this is called first to reference the mesh
+    //     and then again to reference the hull.
+    // Meshes and hulls for the same shape have the same hash key.
+    // NOTE that native shapes are not added to the mesh list or removed.
+    // Returns 'true' if this is the initial reference to the shape. Otherwise reused.
+    public bool ReferenceShape(BulletShape shape)
+    {
+        bool ret = false;
+        switch (shape.type)
+        {
+            case BSPhysicsShapeType.SHAPE_MESH:
+                MeshDesc meshDesc;
+                if (Meshes.TryGetValue(shape.shapeKey, out meshDesc))
+                {
+                    // There is an existing instance of this mesh.
+                    meshDesc.referenceCount++;
+                    if (DDetail) DetailLog("{0},BSShapeCollection.ReferenceShape,existingMesh,key={1},cnt={2}",
+                                BSScene.DetailLogZero, shape.shapeKey.ToString("X"), meshDesc.referenceCount);
+                }
+                else
+                {
+                    // This is a new reference to a mesh
+                    meshDesc.ptr = shape.ptr;
+                    meshDesc.shapeKey = shape.shapeKey;
+                    // We keep a reference to the underlying IMesh data so a hull can be built
+                    meshDesc.referenceCount = 1;
+                    if (DDetail) DetailLog("{0},BSShapeCollection.ReferenceShape,newMesh,key={1},cnt={2}",
+                                BSScene.DetailLogZero, shape.shapeKey.ToString("X"), meshDesc.referenceCount);
+                    ret = true;
+                }
+                meshDesc.lastReferenced = System.DateTime.Now;
+                Meshes[shape.shapeKey] = meshDesc;
+                break;
+            case BSPhysicsShapeType.SHAPE_HULL:
+                HullDesc hullDesc;
+                if (Hulls.TryGetValue(shape.shapeKey, out hullDesc))
+                {
+                    // There is an existing instance of this hull.
+                    hullDesc.referenceCount++;
+                    if (DDetail) DetailLog("{0},BSShapeCollection.ReferenceShape,existingHull,key={1},cnt={2}",
+                                BSScene.DetailLogZero, shape.shapeKey.ToString("X"), hullDesc.referenceCount);
+                }
+                else
+                {
+                    // This is a new reference to a hull
+                    hullDesc.ptr = shape.ptr;
+                    hullDesc.shapeKey = shape.shapeKey;
+                    hullDesc.referenceCount = 1;
+                    if (DDetail) DetailLog("{0},BSShapeCollection.ReferenceShape,newHull,key={1},cnt={2}",
+                                BSScene.DetailLogZero, shape.shapeKey.ToString("X"), hullDesc.referenceCount);
+                    ret = true;
+
+                }
+                hullDesc.lastReferenced = System.DateTime.Now;
+                Hulls[shape.shapeKey] = hullDesc;
+                break;
+            case BSPhysicsShapeType.SHAPE_UNKNOWN:
+                break;
+            default:
+                // Native shapes are not tracked and they don't go into any list
+                break;
+        }
+        return ret;
+    }
+
+    // Release the usage of a shape.
+    public void DereferenceShape(BulletShape shape, bool inTaintTime, ShapeDestructionCallback shapeCallback)
+    {
+        if (!shape.HasPhysicalShape)
+            return;
+
+        PhysicsScene.TaintedObject(inTaintTime, "BSShapeCollection.DereferenceShape", delegate()
+        {
+            if (shape.HasPhysicalShape)
+            {
+                if (shape.isNativeShape)
+                {
+                    // Native shapes are not tracked and are released immediately
+                    if (DDetail) DetailLog("{0},BSShapeCollection.DereferenceShape,deleteNativeShape,ptr={1},taintTime={2}",
+                                    BSScene.DetailLogZero, shape.ptr.ToString(), inTaintTime);
+                    if (shapeCallback != null) shapeCallback(shape);
+                    BulletSimAPI.DeleteCollisionShape2(PhysicsScene.World.ptr, shape.ptr);
+                }
+                else
+                {
+                    switch (shape.type)
+                    {
+                        case BSPhysicsShapeType.SHAPE_HULL:
+                            DereferenceHull(shape, shapeCallback);
+                            break;
+                        case BSPhysicsShapeType.SHAPE_MESH:
+                            DereferenceMesh(shape, shapeCallback);
+                            break;
+                        case BSPhysicsShapeType.SHAPE_COMPOUND:
+                            DereferenceCompound(shape, shapeCallback);
+                            break;
+                        case BSPhysicsShapeType.SHAPE_UNKNOWN:
+                            break;
+                        default:
+                            break;
+                    }
+                }
+            }
+        });
+    }
+
+    // Count down the reference count for a mesh shape
+    // Called at taint-time.
+    private void DereferenceMesh(BulletShape shape, ShapeDestructionCallback shapeCallback)
+    {
+        MeshDesc meshDesc;
+        if (Meshes.TryGetValue(shape.shapeKey, out meshDesc))
+        {
+            meshDesc.referenceCount--;
+            // TODO: release the Bullet storage
+            if (shapeCallback != null) shapeCallback(shape);
+            meshDesc.lastReferenced = System.DateTime.Now;
+            Meshes[shape.shapeKey] = meshDesc;
+            if (DDetail) DetailLog("{0},BSShapeCollection.DereferenceMesh,shape={1},refCnt={2}",
+                                BSScene.DetailLogZero, shape, meshDesc.referenceCount);
+
+        }
+    }
+
+    // Count down the reference count for a hull shape
+    // Called at taint-time.
+    private void DereferenceHull(BulletShape shape, ShapeDestructionCallback shapeCallback)
+    {
+        HullDesc hullDesc;
+        if (Hulls.TryGetValue(shape.shapeKey, out hullDesc))
+        {
+            hullDesc.referenceCount--;
+            // TODO: release the Bullet storage (aging old entries?)
+
+            // Tell upper layers that, if they have dependencies on this shape, this link is going away
+            if (shapeCallback != null) shapeCallback(shape);
+
+            hullDesc.lastReferenced = System.DateTime.Now;
+            Hulls[shape.shapeKey] = hullDesc;
+            if (DDetail) DetailLog("{0},BSShapeCollection.DereferenceHull,shape={1},refCnt={2}",
+                    BSScene.DetailLogZero, shape, hullDesc.referenceCount);
+        }
+    }
+
+    // Remove a reference to a compound shape.
+    // Taking a compound shape apart is a little tricky because if you just delete the
+    //      physical shape, it will free all the underlying children. We can't do that because
+    //      they could be shared. So, this removes each of the children from the compound and
+    //      dereferences them separately before destroying the compound collision object itself.
+    // Called at taint-time.
+    private void DereferenceCompound(BulletShape shape, ShapeDestructionCallback shapeCallback)
+    {
+        if (!BulletSimAPI.IsCompound2(shape.ptr))
+        {
+            // Failed the sanity check!!
+            PhysicsScene.Logger.ErrorFormat("{0} Attempt to free a compound shape that is not compound!! type={1}, ptr={2}",
+                                        LogHeader, shape.type, shape.ptr.ToString());
+            if (DDetail) DetailLog("{0},BSShapeCollection.DereferenceCompound,notACompoundShape,type={1},ptr={2}",
+                                        BSScene.DetailLogZero, shape.type, shape.ptr.ToString());
+            return;
+        }
+
+        int numChildren = BulletSimAPI.GetNumberOfCompoundChildren2(shape.ptr);
+        if (DDetail) DetailLog("{0},BSShapeCollection.DereferenceCompound,shape={1},children={2}", BSScene.DetailLogZero, shape, numChildren);
+
+        for (int ii = numChildren - 1; ii >= 0; ii--)
+        {
+            Object childShape = BulletSimAPI.RemoveChildShapeFromCompoundShapeIndex2(shape.ptr, ii);
+            DereferenceAnonCollisionShape(childShape);
+        }
+        BulletSimAPI.DeleteCollisionShape2(PhysicsScene.World.ptr, shape.ptr);
+    }
+
+    // Sometimes we have a pointer to a collision shape but don't know what type it is.
+    // Figure out type and call the correct dereference routine.
+    // Called at taint-time.
+    private void DereferenceAnonCollisionShape(Object cShape)
+    {
+        MeshDesc meshDesc;
+        HullDesc hullDesc;
+
+        BulletShape shapeInfo = new BulletShape(cShape);
+        if (TryGetMeshByPtr(cShape, out meshDesc))
+        {
+            shapeInfo.type = BSPhysicsShapeType.SHAPE_MESH;
+            shapeInfo.shapeKey = meshDesc.shapeKey;
+        }
+        else
+        {
+            if (TryGetHullByPtr(cShape, out hullDesc))
+            {
+                shapeInfo.type = BSPhysicsShapeType.SHAPE_HULL;
+                shapeInfo.shapeKey = hullDesc.shapeKey;
+            }
+            else
+            {
+                if (BulletSimAPI.IsCompound2(cShape))
+                {
+                    shapeInfo.type = BSPhysicsShapeType.SHAPE_COMPOUND;
+                }
+                else
+                {
+                    if (BulletSimAPI.IsNativeShape2(cShape))
+                    {
+                        shapeInfo.isNativeShape = true;
+                        shapeInfo.type = BSPhysicsShapeType.SHAPE_BOX; // (technically, type doesn't matter)
+                    }
+                }
+            }
+        }
+
+        if (DDetail) DetailLog("{0},BSShapeCollection.DereferenceAnonCollisionShape,shape={1}", BSScene.DetailLogZero, shapeInfo);
+
+        if (shapeInfo.type != BSPhysicsShapeType.SHAPE_UNKNOWN)
+        {
+            DereferenceShape(shapeInfo, true, null);
+        }
+        else
+        {
+            PhysicsScene.Logger.ErrorFormat("{0} Could not decypher shape type. Region={1}, addr={2}",
+                                    LogHeader, PhysicsScene.RegionName, cShape.ToString());
+        }
+    }
+
+    // Create the geometry information in Bullet for later use.
+    // The objects needs a hull if it's physical otherwise a mesh is enough.
+    // if 'forceRebuild' is true, the geometry is unconditionally rebuilt. For meshes and hulls,
+    //     shared geometries will be used. If the parameters of the existing shape are the same
+    //     as this request, the shape is not rebuilt.
+    // Info in prim.BSShape is updated to the new shape.
+    // Returns 'true' if the geometry was rebuilt.
+    // Called at taint-time!
+    private bool CreateGeom(bool forceRebuild, BSPhysObject prim, ShapeDestructionCallback shapeCallback)
+    {
+        bool ret = false;
+        bool haveShape = false;
+
+        if (!haveShape && prim.PreferredPhysicalShape == BSPhysicsShapeType.SHAPE_CAPSULE)
+        {
+            // an avatar capsule is close to a native shape (it is not shared)
+            GetReferenceToNativeShape(prim, BSPhysicsShapeType.SHAPE_CAPSULE,
+                            FixedShapeKey.KEY_CAPSULE, shapeCallback);
+            if (DDetail) DetailLog("{0},BSShapeCollection.CreateGeom,avatarCapsule,shape={1}", prim.LocalID, prim.PhysShape);
+            ret = true;
+            haveShape = true;
+        }
+
+        // Compound shapes are handled special as they are rebuilt from scratch.
+        // This isn't too great a hardship since most of the child shapes will have already been created.
+        if (!haveShape && prim.PreferredPhysicalShape == BSPhysicsShapeType.SHAPE_COMPOUND)
+        {
+            ret = GetReferenceToCompoundShape(prim, shapeCallback);
+            if (DDetail) DetailLog("{0},BSShapeCollection.CreateGeom,compoundShape,shape={1}", prim.LocalID, prim.PhysShape);
+            haveShape = true;
+        }
+
+        if (!haveShape)
+        {
+            ret = CreateGeomNonSpecial(forceRebuild, prim, shapeCallback);
+        }
+
+        return ret;
+    }
+
+    // Create a mesh/hull shape or a native shape if 'nativeShapePossible' is 'true'.
+    public bool CreateGeomNonSpecial(bool forceRebuild, BSPhysObject prim, ShapeDestructionCallback shapeCallback)
+    {
+        bool ret = false;
+        bool haveShape = false;
+        bool nativeShapePossible = true;
+        PrimitiveBaseShape pbs = prim.BaseShape;
+
+        // If the prim attributes are simple, this could be a simple Bullet native shape
+        if (!haveShape
+                && pbs != null
+                && nativeShapePossible
+                && ((pbs.SculptEntry && !BSParam.ShouldMeshSculptedPrim)
+                    || (pbs.ProfileBegin == 0 && pbs.ProfileEnd == 0
+                        && pbs.ProfileHollow == 0
+                        && pbs.PathTwist == 0 && pbs.PathTwistBegin == 0
+                        && pbs.PathBegin == 0 && pbs.PathEnd == 0
+                        && pbs.PathTaperX == 0 && pbs.PathTaperY == 0
+                        && pbs.PathScaleX == 100 && pbs.PathScaleY == 100
+                        && pbs.PathShearX == 0 && pbs.PathShearY == 0) ) )
+        {
+            // Get the scale of any existing shape so we can see if the new shape is same native type and same size.
+            OMV.Vector3 scaleOfExistingShape = OMV.Vector3.Zero;
+            if (prim.PhysShape.HasPhysicalShape)
+                scaleOfExistingShape = BulletSimAPI.GetLocalScaling2(prim.PhysShape.ptr);
+
+            if (DDetail) DetailLog("{0},BSShapeCollection.CreateGeom,maybeNative,force={1},primScale={2},primSize={3},primShape={4}",
+                        prim.LocalID, forceRebuild, prim.Scale, prim.Size, prim.PhysShape.type);
+
+            // It doesn't look like Bullet scales spheres so make sure the scales are all equal
+            if ((pbs.ProfileShape == ProfileShape.HalfCircle && pbs.PathCurve == (byte)Extrusion.Curve1)
+                                && pbs.Scale.X == pbs.Scale.Y && pbs.Scale.Y == pbs.Scale.Z)
+            {
+                haveShape = true;
+                if (forceRebuild
+                        || prim.Scale != scaleOfExistingShape
+                        || prim.PhysShape.type != BSPhysicsShapeType.SHAPE_SPHERE
+                        )
+                {
+                    ret = GetReferenceToNativeShape(prim, BSPhysicsShapeType.SHAPE_SPHERE,
+                                            FixedShapeKey.KEY_SPHERE, shapeCallback);
+                    if (DDetail) DetailLog("{0},BSShapeCollection.CreateGeom,sphere,force={1},shape={2}",
+                                        prim.LocalID, forceRebuild, prim.PhysShape);
+                }
+            }
+            if (!haveShape && pbs.ProfileShape == ProfileShape.Square && pbs.PathCurve == (byte)Extrusion.Straight)
+            {
+                haveShape = true;
+                if (forceRebuild
+                        || prim.Scale != scaleOfExistingShape
+                        || prim.PhysShape.type != BSPhysicsShapeType.SHAPE_BOX
+                        )
+                {
+                    ret = GetReferenceToNativeShape( prim, BSPhysicsShapeType.SHAPE_BOX,
+                                            FixedShapeKey.KEY_BOX, shapeCallback);
+                    if (DDetail) DetailLog("{0},BSShapeCollection.CreateGeom,box,force={1},shape={2}",
+                                        prim.LocalID, forceRebuild, prim.PhysShape);
+                }
+            }
+        }
+
+        // If a simple shape is not happening, create a mesh and possibly a hull.
+        if (!haveShape && pbs != null)
+        {
+            ret = CreateGeomMeshOrHull(prim, shapeCallback);
+        }
+
+        return ret;
+    }
+
+    public bool CreateGeomMeshOrHull(BSPhysObject prim, ShapeDestructionCallback shapeCallback)
+    {
+
+        bool ret = false;
+        // Note that if it's a native shape, the check for physical/non-physical is not
+        //     made. Native shapes work in either case.
+        if (prim.IsPhysical && BSParam.ShouldUseHullsForPhysicalObjects)
+        {
+            // Update prim.BSShape to reference a hull of this shape.
+            ret = GetReferenceToHull(prim,shapeCallback);
+            if (DDetail) DetailLog("{0},BSShapeCollection.CreateGeom,hull,shape={1},key={2}",
+                                    prim.LocalID, prim.PhysShape, prim.PhysShape.shapeKey.ToString("X"));
+        }
+        else
+        {
+            ret = GetReferenceToMesh(prim, shapeCallback);
+            if (DDetail) DetailLog("{0},BSShapeCollection.CreateGeom,mesh,shape={1},key={2}",
+                                    prim.LocalID, prim.PhysShape, prim.PhysShape.shapeKey.ToString("X"));
+        }
+        return ret;
+    }
+
+    // Creates a native shape and assignes it to prim.BSShape.
+    // "Native" shapes are never shared. they are created here and destroyed in DereferenceShape().
+    private bool GetReferenceToNativeShape(BSPhysObject prim,
+                            BSPhysicsShapeType shapeType, FixedShapeKey shapeKey,
+                            ShapeDestructionCallback shapeCallback)
+    {
+        // release any previous shape
+        DereferenceShape(prim.PhysShape, true, shapeCallback);
+
+        BulletShape newShape = BuildPhysicalNativeShape(prim, shapeType, shapeKey);
+
+        // Don't need to do a 'ReferenceShape()' here because native shapes are not shared.
+        if (DDetail) DetailLog("{0},BSShapeCollection.AddNativeShapeToPrim,create,newshape={1},scale={2}",
+                                prim.LocalID, newShape, prim.Scale);
+
+        // native shapes are scaled by Bullet
+        prim.PhysShape = newShape;
+        return true;
+    }
+
+    private BulletShape BuildPhysicalNativeShape(BSPhysObject prim, BSPhysicsShapeType shapeType,
+                                    FixedShapeKey shapeKey)
+    {
+        BulletShape newShape;
+        // Need to make sure the passed shape information is for the native type.
+        ShapeData nativeShapeData = new ShapeData();
+        nativeShapeData.Type = shapeType;
+        nativeShapeData.ID = prim.LocalID;
+        nativeShapeData.Scale = prim.Scale;
+        nativeShapeData.Size = prim.Scale;  // unneeded, I think.
+        nativeShapeData.MeshKey = (ulong)shapeKey;
+        nativeShapeData.HullKey = (ulong)shapeKey;
+
+        if (shapeType == BSPhysicsShapeType.SHAPE_CAPSULE)
+        {
+            // The proper scale has been calculated in the prim.
+            newShape = new BulletShape(
+                        BulletSimAPI.BuildCapsuleShape2(PhysicsScene.World.ptr, 1f, 1f, prim.Scale)
+                        , shapeType);
+            if (DDetail) DetailLog("{0},BSShapeCollection.BuiletPhysicalNativeShape,capsule,scale={1}", prim.LocalID, prim.Scale);
+        }
+        else
+        {
+            // Native shapes are scaled in Bullet so set the scaling to the size
+            newShape = new BulletShape(BulletSimAPI.BuildNativeShape2(PhysicsScene.World.ptr, nativeShapeData), shapeType);
+        }
+        if (!newShape.HasPhysicalShape)
+        {
+            PhysicsScene.Logger.ErrorFormat("{0} BuildPhysicalNativeShape failed. ID={1}, shape={2}",
+                                    LogHeader, prim.LocalID, shapeType);
+        }
+        newShape.shapeKey = (System.UInt64)shapeKey;
+        newShape.isNativeShape = true;
+
+        return newShape;
+    }
+
+    // Builds a mesh shape in the physical world and updates prim.BSShape.
+    // Dereferences previous shape in BSShape and adds a reference for this new shape.
+    // Returns 'true' of a mesh was actually built. Otherwise .
+    // Called at taint-time!
+    private bool GetReferenceToMesh(BSPhysObject prim, ShapeDestructionCallback shapeCallback)
+    {
+        BulletShape newShape = new BulletShape();
+
+        float lod;
+        System.UInt64 newMeshKey = ComputeShapeKey(prim.Size, prim.BaseShape, out lod);
+
+        // if this new shape is the same as last time, don't recreate the mesh
+        if (newMeshKey == prim.PhysShape.shapeKey && prim.PhysShape.type == BSPhysicsShapeType.SHAPE_MESH)
+            return false;
+
+        if (DDetail) DetailLog("{0},BSShapeCollection.GetReferenceToMesh,create,oldKey={1},newKey={2}",
+                                prim.LocalID, prim.PhysShape.shapeKey.ToString("X"), newMeshKey.ToString("X"));
+
+        // Since we're recreating new, get rid of the reference to the previous shape
+        DereferenceShape(prim.PhysShape, true, shapeCallback);
+
+        newShape = CreatePhysicalMesh(prim.PhysObjectName, newMeshKey, prim.BaseShape, prim.Size, lod);
+        // Take evasive action if the mesh was not constructed.
+        newShape = VerifyMeshCreated(newShape, prim);
+
+        ReferenceShape(newShape);
+
+        prim.PhysShape = newShape;
+
+        return true;        // 'true' means a new shape has been added to this prim
+    }
+
+    private BulletShape CreatePhysicalMesh(string objName, System.UInt64 newMeshKey, PrimitiveBaseShape pbs, OMV.Vector3 size, float lod)
+    {
+        IMesh meshData = null;
+        Object meshPtr = null;
+        MeshDesc meshDesc;
+        if (Meshes.TryGetValue(newMeshKey, out meshDesc))
+        {
+            // If the mesh has already been built just use it.
+            meshPtr = meshDesc.ptr;
+        }
+        else
+        {
+            meshData = PhysicsScene.mesher.CreateMesh(objName, pbs, size, lod, true, false);
+
+            if (meshData != null)
+            {
+                int[] indices = meshData.getIndexListAsInt();
+                List<OMV.Vector3> vertices = meshData.getVertexList();
+
+                float[] verticesAsFloats = new float[vertices.Count * 3];
+                int vi = 0;
+                foreach (OMV.Vector3 vv in vertices)
+                {
+                    verticesAsFloats[vi++] = vv.X;
+                    verticesAsFloats[vi++] = vv.Y;
+                    verticesAsFloats[vi++] = vv.Z;
+                }
+
+                // m_log.DebugFormat("{0}: BSShapeCollection.CreatePhysicalMesh: calling CreateMesh. lid={1}, key={2}, indices={3}, vertices={4}",
+                //                  LogHeader, prim.LocalID, newMeshKey, indices.Length, vertices.Count);
+
+                meshPtr = BulletSimAPI.CreateMeshShape2(PhysicsScene.World.ptr,
+                                    indices.GetLength(0), indices, vertices.Count, verticesAsFloats);
+            }
+        }
+        BulletShape newShape = new BulletShape(meshPtr, BSPhysicsShapeType.SHAPE_MESH);
+        newShape.shapeKey = newMeshKey;
+
+        return newShape;
+    }
+
+    // See that hull shape exists in the physical world and update prim.BSShape.
+    // We could be creating the hull because scale changed or whatever.
+    private bool GetReferenceToHull(BSPhysObject prim, ShapeDestructionCallback shapeCallback)
+    {
+        BulletShape newShape;
+
+        float lod;
+        System.UInt64 newHullKey = ComputeShapeKey(prim.Size, prim.BaseShape, out lod);
+
+        // if the hull hasn't changed, don't rebuild it
+        if (newHullKey == prim.PhysShape.shapeKey && prim.PhysShape.type == BSPhysicsShapeType.SHAPE_HULL)
+            return false;
+
+        if (DDetail) DetailLog("{0},BSShapeCollection.GetReferenceToHull,create,oldKey={1},newKey={2}",
+                        prim.LocalID, prim.PhysShape.shapeKey.ToString("X"), newHullKey.ToString("X"));
+
+        // Remove usage of the previous shape.
+        DereferenceShape(prim.PhysShape, true, shapeCallback);
+
+        newShape = CreatePhysicalHull(prim.PhysObjectName, newHullKey, prim.BaseShape, prim.Size, lod);
+        newShape = VerifyMeshCreated(newShape, prim);
+
+        ReferenceShape(newShape);
+
+        prim.PhysShape = newShape;
+        return true;        // 'true' means a new shape has been added to this prim
+    }
+
+    List<ConvexResult> m_hulls;
+    private BulletShape CreatePhysicalHull(string objName, System.UInt64 newHullKey, PrimitiveBaseShape pbs, OMV.Vector3 size, float lod)
+    {
+
+        Object hullPtr = null;
+        HullDesc hullDesc;
+        if (Hulls.TryGetValue(newHullKey, out hullDesc))
+        {
+            // If the hull shape already is created, just use it.
+            hullPtr = hullDesc.ptr;
+        }
+        else
+        {
+            // Build a new hull in the physical world
+            // Pass true for physicalness as this creates some sort of bounding box which we don't need
+            IMesh meshData = PhysicsScene.mesher.CreateMesh(objName, pbs, size, lod, true, false);
+            if (meshData != null)
+            {
+
+                int[] indices = meshData.getIndexListAsInt();
+                List<OMV.Vector3> vertices = meshData.getVertexList();
+
+                //format conversion from IMesh format to DecompDesc format
+                List<int> convIndices = new List<int>();
+                List<float3> convVertices = new List<float3>();
+                for (int ii = 0; ii < indices.GetLength(0); ii++)
+                {
+                    convIndices.Add(indices[ii]);
+                }
+                foreach (OMV.Vector3 vv in vertices)
+                {
+                    convVertices.Add(new float3(vv.X, vv.Y, vv.Z));
+                }
+
+                // setup and do convex hull conversion
+                m_hulls = new List<ConvexResult>();
+                DecompDesc dcomp = new DecompDesc();
+                dcomp.mIndices = convIndices;
+                dcomp.mVertices = convVertices;
+                ConvexBuilder convexBuilder = new ConvexBuilder(HullReturn);
+                // create the hull into the _hulls variable
+                convexBuilder.process(dcomp);
+
+                // Convert the vertices and indices for passing to unmanaged.
+                // The hull information is passed as a large floating point array.
+                // The format is:
+                //  convHulls[0] = number of hulls
+                //  convHulls[1] = number of vertices in first hull
+                //  convHulls[2] = hull centroid X coordinate
+                //  convHulls[3] = hull centroid Y coordinate
+                //  convHulls[4] = hull centroid Z coordinate
+                //  convHulls[5] = first hull vertex X
+                //  convHulls[6] = first hull vertex Y
+                //  convHulls[7] = first hull vertex Z
+                //  convHulls[8] = second hull vertex X
+                //  ...
+                //  convHulls[n] = number of vertices in second hull
+                //  convHulls[n+1] = second hull centroid X coordinate
+                //  ...
+                //
+                // TODO: is is very inefficient. Someday change the convex hull generator to return
+                //   data structures that do not need to be converted in order to pass to Bullet.
+                //   And maybe put the values directly into pinned memory rather than marshaling.
+                int hullCount = m_hulls.Count;
+                int totalVertices = 1;          // include one for the count of the hulls
+                foreach (ConvexResult cr in m_hulls)
+                {
+                    totalVertices += 4;                         // add four for the vertex count and centroid
+                    totalVertices += cr.HullIndices.Count * 3;  // we pass just triangles
+                }
+                float[] convHulls = new float[totalVertices];
+
+                convHulls[0] = (float)hullCount;
+                int jj = 1;
+                foreach (ConvexResult cr in m_hulls)
+                {
+                    // copy vertices for index access
+                    float3[] verts = new float3[cr.HullVertices.Count];
+                    int kk = 0;
+                    foreach (float3 ff in cr.HullVertices)
+                    {
+                        verts[kk++] = ff;
+                    }
+
+                    // add to the array one hull's worth of data
+                    convHulls[jj++] = cr.HullIndices.Count;
+                    convHulls[jj++] = 0f;   // centroid x,y,z
+                    convHulls[jj++] = 0f;
+                    convHulls[jj++] = 0f;
+                    foreach (int ind in cr.HullIndices)
+                    {
+                        convHulls[jj++] = verts[ind].x;
+                        convHulls[jj++] = verts[ind].y;
+                        convHulls[jj++] = verts[ind].z;
+                    }
+                }
+                // create the hull data structure in Bullet
+                hullPtr = BulletSimAPI.CreateHullShape2(PhysicsScene.World.ptr, hullCount, convHulls);
+            }
+        }
+
+        BulletShape newShape = new BulletShape(hullPtr, BSPhysicsShapeType.SHAPE_HULL);
+        newShape.shapeKey = newHullKey;
+
+        return newShape;
+    }
+
+    // Callback from convex hull creater with a newly created hull.
+    // Just add it to our collection of hulls for this shape.
+    private void HullReturn(ConvexResult result)
+    {
+        m_hulls.Add(result);
+        return;
+    }
+
+    // Compound shapes are always built from scratch.
+    // This shouldn't be to bad since most of the parts will be meshes that had been built previously.
+    private bool GetReferenceToCompoundShape(BSPhysObject prim, ShapeDestructionCallback shapeCallback)
+    {
+        // Remove reference to the old shape
+        // Don't need to do this as the shape is freed when the new root shape is created below.
+        // DereferenceShape(prim.PhysShape, true, shapeCallback);
+
+        BulletShape cShape = new BulletShape(
+            BulletSimAPI.CreateCompoundShape2(PhysicsScene.World.ptr, false), BSPhysicsShapeType.SHAPE_COMPOUND);
+
+        // Create the shape for the root prim and add it to the compound shape. Cannot be a native shape.
+        CreateGeomMeshOrHull(prim, shapeCallback);
+        BulletSimAPI.AddChildShapeToCompoundShape2(cShape.ptr, prim.PhysShape.ptr, OMV.Vector3.Zero, OMV.Quaternion.Identity);
+        if (DDetail) DetailLog("{0},BSShapeCollection.GetReferenceToCompoundShape,addRootPrim,compShape={1},rootShape={2}",
+                                    prim.LocalID, cShape, prim.PhysShape);
+
+        prim.PhysShape = cShape;
+
+        return true;
+    }
+
+    // Create a hash of all the shape parameters to be used as a key
+    //    for this particular shape.
+    private System.UInt64 ComputeShapeKey(OMV.Vector3 size, PrimitiveBaseShape pbs, out float retLod)
+    {
+        // level of detail based on size and type of the object
+        float lod = BSParam.MeshLOD;
+        if (pbs.SculptEntry)
+            lod = BSParam.SculptLOD;
+
+        // Mega prims usually get more detail because one can interact with shape approximations at this size.
+        float maxAxis = Math.Max(size.X, Math.Max(size.Y, size.Z));
+        if (maxAxis > BSParam.MeshMegaPrimThreshold)
+            lod = BSParam.MeshMegaPrimLOD;
+
+        retLod = lod;
+        return pbs.GetMeshKey(size, lod);
+    }
+    // For those who don't want the LOD
+    private System.UInt64 ComputeShapeKey(OMV.Vector3 size, PrimitiveBaseShape pbs)
+    {
+        float lod;
+        return ComputeShapeKey(size, pbs, out lod);
+    }
+
+    // The creation of a mesh or hull can fail if an underlying asset is not available.
+    // There are two cases: 1) the asset is not in the cache and it needs to be fetched;
+    //     and 2) the asset cannot be converted (like failed decompression of JPEG2000s).
+    //     The first case causes the asset to be fetched. The second case requires
+    //     us to not loop forever.
+    // Called after creating a physical mesh or hull. If the physical shape was created,
+    //     just return.
+    private BulletShape VerifyMeshCreated(BulletShape newShape, BSPhysObject prim)
+    {
+        // If the shape was successfully created, nothing more to do
+        if (newShape.HasPhysicalShape)
+            return newShape;
+
+        // If this mesh has an underlying asset and we have not failed getting it before, fetch the asset
+        if (prim.BaseShape.SculptEntry && !prim.LastAssetBuildFailed && prim.BaseShape.SculptTexture != OMV.UUID.Zero)
+        {
+            prim.LastAssetBuildFailed = true;
+            BSPhysObject xprim = prim;
+            DetailLog("{0},BSShapeCollection.VerifyMeshCreated,fetchAsset,lID={1},lastFailed={2}",
+                            LogHeader, prim.LocalID, prim.LastAssetBuildFailed);
+            Util.FireAndForget(delegate
+                {
+                    RequestAssetDelegate assetProvider = PhysicsScene.RequestAssetMethod;
+                    if (assetProvider != null)
+                    {
+                        BSPhysObject yprim = xprim; // probably not necessary, but, just in case.
+                        assetProvider(yprim.BaseShape.SculptTexture, delegate(AssetBase asset)
+                        {
+                            if (!yprim.BaseShape.SculptEntry)
+                                return;
+                            if (yprim.BaseShape.SculptTexture.ToString() != asset.ID)
+                                return;
+
+                            yprim.BaseShape.SculptData = asset.Data;
+                            // This will cause the prim to see that the filler shape is not the right
+                            //    one and try again to build the object.
+                            // No race condition with the normal shape setting since the rebuild is at taint time.
+                            yprim.ForceBodyShapeRebuild(false);
+
+                        });
+                    }
+                });
+        }
+        else
+        {
+            if (prim.LastAssetBuildFailed)
+            {
+                PhysicsScene.Logger.ErrorFormat("{0} Mesh failed to fetch asset. lID={1}, texture={2}",
+                                            LogHeader, prim.LocalID, prim.BaseShape.SculptTexture);
+            }
+        }
+
+        // While we figure out the real problem, stick a simple native shape on the object.
+        BulletShape fillinShape =
+            BuildPhysicalNativeShape(prim, BSPhysicsShapeType.SHAPE_BOX, FixedShapeKey.KEY_BOX);
+
+        return fillinShape;
+    }
+
+    // Create a body object in Bullet.
+    // 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,
+                            BodyDestructionCallback bodyCallback)
+    {
+        bool ret = false;
+
+        // the mesh, hull or native shape must have already been created in Bullet
+        bool mustRebuild = !prim.PhysBody.HasPhysicalBody;
+
+        // If there is an existing body, verify it's of an acceptable type.
+        // If not a solid object, body is a GhostObject. Otherwise a RigidBody.
+        if (!mustRebuild)
+        {
+            CollisionObjectTypes bodyType = (CollisionObjectTypes)BulletSimAPI.GetBodyType2(prim.PhysBody.ptr);
+            if (prim.IsSolid && bodyType != CollisionObjectTypes.CO_RIGID_BODY
+                || !prim.IsSolid && bodyType != CollisionObjectTypes.CO_GHOST_OBJECT)
+            {
+                // If the collisionObject is not the correct type for solidness, rebuild what's there
+                mustRebuild = true;
+            }
+        }
+
+        if (mustRebuild || forceRebuild)
+        {
+            // Free any old body
+            DereferenceBody(prim.PhysBody, true, bodyCallback);
+
+            BulletBody aBody;
+            Object bodyPtr = null;
+            if (prim.IsSolid)
+            {
+                bodyPtr = BulletSimAPI.CreateBodyFromShape2(sim.ptr, shape.ptr,
+                                        prim.LocalID, prim.RawPosition, prim.RawOrientation);
+                if (DDetail) DetailLog("{0},BSShapeCollection.CreateBody,mesh,ptr={1}", prim.LocalID, bodyPtr.ToString());
+            }
+            else
+            {
+                bodyPtr = BulletSimAPI.CreateGhostFromShape2(sim.ptr, shape.ptr,
+                                        prim.LocalID, prim.RawPosition, prim.RawOrientation);
+                if (DDetail) DetailLog("{0},BSShapeCollection.CreateBody,ghost,ptr={1}", prim.LocalID, bodyPtr.ToString());
+            }
+            aBody = new BulletBody(prim.LocalID, bodyPtr);
+
+            ReferenceBody(aBody, true);
+
+            prim.PhysBody = aBody;
+
+            ret = true;
+        }
+
+        return ret;
+    }
+
+    private bool TryGetMeshByPtr(Object addr, out MeshDesc outDesc)
+    {
+        bool ret = false;
+        MeshDesc foundDesc = new MeshDesc();
+        foreach (MeshDesc md in Meshes.Values)
+        {
+            if (md.ptr == addr)
+            {
+                foundDesc = md;
+                ret = true;
+                break;
+            }
+
+        }
+        outDesc = foundDesc;
+        return ret;
+    }
+
+    private bool TryGetHullByPtr(Object addr, out HullDesc outDesc)
+    {
+        bool ret = false;
+        HullDesc foundDesc = new HullDesc();
+        foreach (HullDesc hd in Hulls.Values)
+        {
+            if (hd.ptr == addr)
+            {
+                foundDesc = hd;
+                ret = true;
+                break;
+            }
+
+        }
+        outDesc = foundDesc;
+        return ret;
+    }
+
+    private void DetailLog(string msg, params Object[] args)
+    {
+        if (PhysicsScene.PhysicsLogging.Enabled)
+            PhysicsScene.DetailLog(msg, args);
+    }
+}
+}