1 files changed, 373 insertions, 401 deletions

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs b/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
index a31c578..2c3c481 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
@@ -39,33 +39,27 @@ using log4net;
 using OpenMetaverse;
 
 // TODOs for BulletSim (for BSScene, BSPrim, BSCharacter and BulletSim)
-// Debug linkset 
-// Test with multiple regions in one simulator 
-// Adjust character capsule size when height is adjusted (ScenePresence.SetHeight)
-// Test sculpties
+// Test sculpties (verified that they don't work)
 // Compute physics FPS reasonably
 // Based on material, set density and friction
-// More efficient memory usage when passing hull information from BSPrim to BulletSim
-// Move all logic out of the C++ code and into the C# code for easier future modifications.
+// Don't use constraints in linksets of non-physical objects. Means having to move children manually.
 // Four states of prim: Physical, regular, phantom and selected. Are we modeling these correctly?
 //     In SL one can set both physical and phantom (gravity, does not effect others, makes collisions with ground)
 //     At the moment, physical and phantom causes object to drop through the terrain
 // Physical phantom objects and related typing (collision options )
-// Use collision masks for collision with terrain and phantom objects 
 // Check out llVolumeDetect. Must do something for that.
+// Use collision masks for collision with terrain and phantom objects
+// More efficient memory usage when passing hull information from BSPrim to BulletSim
 // Should prim.link() and prim.delink() membership checking happen at taint time?
-// changing the position and orientation of a linked prim must rebuild the constraint with the root.
-// Mesh sharing. Use meshHash to tell if we already have a hull of that shape and only create once
+// Mesh sharing. Use meshHash to tell if we already have a hull of that shape and only create once.
 // Do attachments need to be handled separately? Need collision events. Do not collide with VolumeDetect
-// Implement the genCollisions feature in BulletSim::SetObjectProperties (don't pass up unneeded collisions)
 // Implement LockAngularMotion
 // Decide if clearing forces is the right thing to do when setting position (BulletSim::SetObjectTranslation)
-// Does NeedsMeshing() really need to exclude all the different shapes?
 // Remove mesh and Hull stuff. Use mesh passed to bullet and use convexdecom from bullet.
 // Add PID movement operations. What does ScenePresence.MoveToTarget do?
 // Check terrain size. 128 or 127?
 // Raycast
-// 
+//
 namespace OpenSim.Region.Physics.BulletSPlugin
 {
 public class BSScene : PhysicsScene, IPhysicsParameters
@@ -73,62 +67,56 @@ public class BSScene : PhysicsScene, IPhysicsParameters
     private static readonly ILog m_log = LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
     private static readonly string LogHeader = "[BULLETS SCENE]";
 
-    public void DebugLog(string mm, params Object[] xx) { if (ShouldDebugLog) m_log.DebugFormat(mm, xx); }
+    // The name of the region we're working for.
+    public string RegionName { get; private set; }
 
     public string BulletSimVersion = "?";
 
-    private Dictionary<uint, BSCharacter> m_avatars = new Dictionary<uint, BSCharacter>();
-    private Dictionary<uint, BSPrim> m_prims = new Dictionary<uint, BSPrim>();
-    private HashSet<BSCharacter> m_avatarsWithCollisions = new HashSet<BSCharacter>();
-    private HashSet<BSPrim> m_primsWithCollisions = new HashSet<BSPrim>();
-    private List<BSPrim> m_vehicles = new List<BSPrim>();
-    private float[] m_heightMap;
-    private float m_waterLevel;
-    private uint m_worldID;
-    public uint WorldID { get { return m_worldID; } }
+    public Dictionary<uint, BSPhysObject> PhysObjects;
+    public BSShapeCollection Shapes;
 
-    // let my minuions use my logger
-    public ILog Logger { get { return m_log; } }
+    // Keeping track of the objects with collisions so we can report begin and end of a collision
+    public HashSet<BSPhysObject> ObjectsWithCollisions = new HashSet<BSPhysObject>();
+    public HashSet<BSPhysObject> ObjectsWithNoMoreCollisions = new HashSet<BSPhysObject>();
+    // Keep track of all the avatars so we can send them a collision event
+    //    every tick so OpenSim will update its animation.
+    private HashSet<BSPhysObject> m_avatars = new HashSet<BSPhysObject>();
 
-    private bool m_initialized = false;
+    // List of all the objects that have vehicle properties and should be called
+    //    to update each physics step.
+    private List<BSPhysObject> m_vehicles = new List<BSPhysObject>();
 
-    private int m_detailedStatsStep = 0;
+    // let my minuions use my logger
+    public ILog Logger { get { return m_log; } }
 
     public IMesher mesher;
-    private float m_meshLOD;
-    public float MeshLOD
-    {
-        get { return m_meshLOD; }
-    }
-    private float m_sculptLOD;
-    public float SculptLOD
-    {
-        get { return m_sculptLOD; }
-    }
+    // Level of Detail values kept as float because that's what the Meshmerizer wants
+    public float MeshLOD { get; private set; }
+    public float MeshMegaPrimLOD { get; private set; }
+    public float MeshMegaPrimThreshold { get; private set; }
+    public float SculptLOD { get; private set; }
 
-    private BulletSim m_worldSim;
-    public BulletSim World
-    {
-        get { return m_worldSim; }
-    }
-    private BSConstraintCollection m_constraintCollection;
-    public BSConstraintCollection Constraints
-    { 
-        get { return m_constraintCollection; }
-    }
+    public uint WorldID { get; private set; }
+    public BulletSim World { get; private set; }
 
+    // All the constraints that have been allocated in this instance.
+    public BSConstraintCollection Constraints { get; private set; }
+
+    // Simulation parameters
     private int m_maxSubSteps;
     private float m_fixedTimeStep;
     private long m_simulationStep = 0;
     public long SimulationStep { get { return m_simulationStep; } }
-
-    public float LastSimulatedTimestep { get; private set; }
+    private int m_taintsToProcessPerStep;
 
     // A value of the time now so all the collision and update routines do not have to get their own
     // Set to 'now' just before all the prims and actors are called for collisions and updates
-    private int m_simulationNowTime;
-    public int SimulationNowTime { get { return m_simulationNowTime; } }
+    public int SimulationNowTime { get; private set; }
+
+    // True if initialized and ready to do simulation steps
+    private bool m_initialized = false;
 
+    // Pinned memory used to pass step information between managed and unmanaged
     private int m_maxCollisionsPerFrame;
     private CollisionDesc[] m_collisionArray;
     private GCHandle m_collisionArrayPinnedHandle;
@@ -137,14 +125,19 @@ public class BSScene : PhysicsScene, IPhysicsParameters
     private EntityProperties[] m_updateArray;
     private GCHandle m_updateArrayPinnedHandle;
 
-    private bool _meshSculptedPrim = true;         // cause scuplted prims to get meshed
-    private bool _forceSimplePrimMeshing = false;   // if a cube or sphere, let Bullet do internal shapes
+    public bool ShouldMeshSculptedPrim { get; private set; }   // cause scuplted prims to get meshed
+    public bool ShouldForceSimplePrimMeshing { get; private set; }   // if a cube or sphere, let Bullet do internal shapes
+    public bool ShouldUseHullsForPhysicalObjects { get; private set; }   // 'true' if should create hulls for physical objects
 
     public float PID_D { get; private set; }    // derivative
     public float PID_P { get; private set; }    // proportional
 
     public const uint TERRAIN_ID = 0;       // OpenSim senses terrain with a localID of zero
     public const uint GROUNDPLANE_ID = 1;
+    public const uint CHILDTERRAIN_ID = 2;  // Terrain allocated based on our mega-prim childre start here
+
+    private float m_waterLevel;
+    public BSTerrainManager TerrainManager { get; private set; }
 
     public ConfigurationParameters Params
     {
@@ -154,13 +147,18 @@ public class BSScene : PhysicsScene, IPhysicsParameters
     {
         get { return new Vector3(0f, 0f, Params.gravity); }
     }
-
-    private float m_maximumObjectMass;
-    public float MaximumObjectMass
+    // Just the Z value of the gravity
+    public float DefaultGravityZ
     {
-        get { return m_maximumObjectMass; }
+        get { return Params.gravity; }
     }
 
+    public float MaximumObjectMass { get; private set; }
+
+    // When functions in the unmanaged code must be called, it is only
+    //   done at a known time just before the simulation step. The taint
+    //   system saves all these function calls and executes them in
+    //   order before the simulation.
     public delegate void TaintCallback();
     private struct TaintCallbackEntry
     {
@@ -172,15 +170,17 @@ public class BSScene : PhysicsScene, IPhysicsParameters
             callback = c;
         }
     }
+    private Object _taintLock = new Object();   // lock for using the next object
     private List<TaintCallbackEntry> _taintedObjects;
-    private Object _taintLock = new Object();
 
     // A pointer to an instance if this structure is passed to the C++ code
+    // Used to pass basic configuration values to the unmanaged code.
     ConfigurationParameters[] m_params;
     GCHandle m_paramsHandle;
 
-    public bool ShouldDebugLog { get; private set; }
-
+    // Handle to the callback used by the unmanaged code to call into the managed code.
+    // Used for debug logging.
+    // Need to store the handle in a persistant variable so it won't be freed.
     private BulletSimAPI.DebugLogCallback m_DebugLogCallbackHandle;
 
     // Sometimes you just have to log everything.
@@ -189,17 +189,24 @@ public class BSScene : PhysicsScene, IPhysicsParameters
     private string m_physicsLoggingDir;
     private string m_physicsLoggingPrefix;
     private int m_physicsLoggingFileMinutes;
+    // 'true' of the vehicle code is to log lots of details
+    public bool VehicleLoggingEnabled { get; private set; }
 
-    private bool m_vehicleLoggingEnabled;
-    public bool VehicleLoggingEnabled { get { return m_vehicleLoggingEnabled; } }
-
+    #region Construction and Initialization
     public BSScene(string identifier)
     {
         m_initialized = false;
+        // we are passed the name of the region we're working for.
+        RegionName = identifier;
     }
 
     public override void Initialise(IMesher meshmerizer, IConfigSource config)
     {
+        mesher = meshmerizer;
+        _taintedObjects = new List<TaintCallbackEntry>();
+        PhysObjects = new Dictionary<uint, BSPhysObject>();
+        Shapes = new BSShapeCollection(this);
+
         // Allocate pinned memory to pass parameters.
         m_params = new ConfigurationParameters[1];
         m_paramsHandle = GCHandle.Alloc(m_params, GCHandleType.Pinned);
@@ -215,7 +222,7 @@ public class BSScene : PhysicsScene, IPhysicsParameters
 
         // Enable very detailed logging.
         // By creating an empty logger when not logging, the log message invocation code
-        // can be left in and every call doesn't have to check for null.
+        //     can be left in and every call doesn't have to check for null.
         if (m_physicsLoggingEnabled)
         {
             PhysicsLogging = new Logging.LogWriter(m_physicsLoggingDir, m_physicsLoggingPrefix, m_physicsLoggingFileMinutes);
@@ -225,38 +232,43 @@ public class BSScene : PhysicsScene, IPhysicsParameters
             PhysicsLogging = new Logging.LogWriter();
         }
 
-        // Get the version of the DLL
-        // TODO: this doesn't work yet. Something wrong with marshaling the returned string.
-        // BulletSimVersion = BulletSimAPI.GetVersion();
-        // m_log.WarnFormat("{0}: BulletSim.dll version='{1}'", LogHeader, BulletSimVersion);
-
-        // if Debug, enable logging from the unmanaged code
+        // If Debug logging level, enable logging from the unmanaged code
+        m_DebugLogCallbackHandle = null;
         if (m_log.IsDebugEnabled || PhysicsLogging.Enabled)
         {
             m_log.DebugFormat("{0}: Initialize: Setting debug callback for unmanaged code", LogHeader);
             if (PhysicsLogging.Enabled)
+                // The handle is saved in a variable to make sure it doesn't get freed after this call
                 m_DebugLogCallbackHandle = new BulletSimAPI.DebugLogCallback(BulletLoggerPhysLog);
             else
                 m_DebugLogCallbackHandle = new BulletSimAPI.DebugLogCallback(BulletLogger);
-            // the handle is saved in a variable to make sure it doesn't get freed after this call
-            BulletSimAPI.SetDebugLogCallback(m_DebugLogCallbackHandle);
         }
 
-        _taintedObjects = new List<TaintCallbackEntry>();
+        // Get the version of the DLL
+        // TODO: this doesn't work yet. Something wrong with marshaling the returned string.
+        // BulletSimVersion = BulletSimAPI.GetVersion();
+        // m_log.WarnFormat("{0}: BulletSim.dll version='{1}'", LogHeader, BulletSimVersion);
 
-        mesher = meshmerizer;
-        // The bounding box for the simulated world
-        Vector3 worldExtent = new Vector3(Constants.RegionSize, Constants.RegionSize, 8192f);
+        // The bounding box for the simulated world. The origin is 0,0,0 unless we're
+        //    a child in a mega-region.
+        // Bullet actually doesn't care about the extents of the simulated
+        //    area. It tracks active objects no matter where they are.
+        Vector3 worldExtent = new Vector3(Constants.RegionSize, Constants.RegionSize, Constants.RegionHeight);
 
         // m_log.DebugFormat("{0}: Initialize: Calling BulletSimAPI.Initialize.", LogHeader);
-        m_worldID = BulletSimAPI.Initialize(worldExtent, m_paramsHandle.AddrOfPinnedObject(),
+        WorldID = BulletSimAPI.Initialize(worldExtent, m_paramsHandle.AddrOfPinnedObject(),
                                         m_maxCollisionsPerFrame, m_collisionArrayPinnedHandle.AddrOfPinnedObject(),
-                                        m_maxUpdatesPerFrame, m_updateArrayPinnedHandle.AddrOfPinnedObject());
+                                        m_maxUpdatesPerFrame, m_updateArrayPinnedHandle.AddrOfPinnedObject(),
+                                        m_DebugLogCallbackHandle);
 
         // Initialization to support the transition to a new API which puts most of the logic
         //   into the C# code so it is easier to modify and add to.
-        m_worldSim = new BulletSim(m_worldID, this, BulletSimAPI.GetSimHandle2(m_worldID));
-        m_constraintCollection = new BSConstraintCollection(World);
+        World = new BulletSim(WorldID, this, BulletSimAPI.GetSimHandle2(WorldID));
+
+        Constraints = new BSConstraintCollection(World);
+
+        TerrainManager = new BSTerrainManager(this);
+        TerrainManager.CreateInitialGroundPlaneAndTerrain();
 
         m_initialized = true;
     }
@@ -281,10 +293,13 @@ public class BSScene : PhysicsScene, IPhysicsParameters
                 // Very detailed logging for physics debugging
                 m_physicsLoggingEnabled = pConfig.GetBoolean("PhysicsLoggingEnabled", false);
                 m_physicsLoggingDir = pConfig.GetString("PhysicsLoggingDir", ".");
-                m_physicsLoggingPrefix = pConfig.GetString("PhysicsLoggingPrefix", "physics-");
+                m_physicsLoggingPrefix = pConfig.GetString("PhysicsLoggingPrefix", "physics-%REGIONNAME%-");
                 m_physicsLoggingFileMinutes = pConfig.GetInt("PhysicsLoggingFileMinutes", 5);
                 // Very detailed logging for vehicle debugging
-                m_vehicleLoggingEnabled = pConfig.GetBoolean("VehicleLoggingEnabled", false);
+                VehicleLoggingEnabled = pConfig.GetBoolean("VehicleLoggingEnabled", false);
+
+                // Do any replacements in the parameters
+                m_physicsLoggingPrefix = m_physicsLoggingPrefix.Replace("%REGIONNAME%", RegionName);
             }
         }
     }
@@ -309,12 +324,50 @@ public class BSScene : PhysicsScene, IPhysicsParameters
     {
         m_log.Debug("[BULLETS UNMANAGED]:" + msg);
     }
-    
+  
     // Called directly from unmanaged code so don't do much
     private void BulletLoggerPhysLog(string msg)
     {
-        PhysicsLogging.Write("[BULLETS UNMANAGED]:" + msg);
+        DetailLog("[BULLETS UNMANAGED]:" + msg);
+    }
+
+    public override void Dispose()
+    {
+        // m_log.DebugFormat("{0}: Dispose()", LogHeader);
+
+        // make sure no stepping happens while we're deleting stuff
+        m_initialized = false;
+
+        TerrainManager.ReleaseGroundPlaneAndTerrain();
+
+        foreach (KeyValuePair<uint, BSPhysObject> kvp in PhysObjects)
+        {
+            kvp.Value.Destroy();
+        }
+        PhysObjects.Clear();
+
+        // Now that the prims are all cleaned up, there should be no constraints left
+        if (Constraints != null)
+        {
+            Constraints.Dispose();
+            Constraints = null;
+        }
+
+        if (Shapes != null)
+        {
+            Shapes.Dispose();
+            Shapes = null;
+        }
+
+        // Anything left in the unmanaged code should be cleaned out
+        BulletSimAPI.Shutdown(WorldID);
+
+        // Not logging any more
+        PhysicsLogging.Close();
     }
+    #endregion // Construction and Initialization
+
+    #region Prim and Avatar addition and removal
 
     public override PhysicsActor AddAvatar(string avName, Vector3 position, Vector3 size, bool isFlying)
     {
@@ -329,7 +382,13 @@ public class BSScene : PhysicsScene, IPhysicsParameters
         if (!m_initialized) return null;
 
         BSCharacter actor = new BSCharacter(localID, avName, this, position, size, isFlying);
-        lock (m_avatars) m_avatars.Add(localID, actor);
+        lock (PhysObjects) PhysObjects.Add(localID, actor);
+
+        // TODO: Remove kludge someday.
+        // We must generate a collision for avatars whether they collide or not.
+        // This is required by OpenSim to update avatar animations, etc.
+        lock (m_avatars) m_avatars.Add(actor);
+
         return actor;
     }
 
@@ -344,7 +403,9 @@ public class BSScene : PhysicsScene, IPhysicsParameters
         {
             try
             {
-                lock (m_avatars) m_avatars.Remove(actor.LocalID);
+                lock (PhysObjects) PhysObjects.Remove(actor.LocalID);
+                // Remove kludge someday
+                lock (m_avatars) m_avatars.Remove(bsactor);
             }
             catch (Exception e)
             {
@@ -362,11 +423,11 @@ public class BSScene : PhysicsScene, IPhysicsParameters
         BSPrim bsprim = prim as BSPrim;
         if (bsprim != null)
         {
-            // DetailLog("{0},RemovePrim,call", bsprim.LocalID);
+            DetailLog("{0},RemovePrim,call", bsprim.LocalID);
             // m_log.DebugFormat("{0}: RemovePrim. id={1}/{2}", LogHeader, bsprim.Name, bsprim.LocalID);
             try
             {
-                lock (m_prims) m_prims.Remove(bsprim.LocalID);
+                lock (PhysObjects) PhysObjects.Remove(bsprim.LocalID);
             }
             catch (Exception e)
             {
@@ -388,18 +449,21 @@ public class BSScene : PhysicsScene, IPhysicsParameters
 
         if (!m_initialized) return null;
 
-        // DetailLog("{0},AddPrimShape,call", localID);
+        DetailLog("{0},AddPrimShape,call", localID);
 
         BSPrim prim = new BSPrim(localID, primName, this, position, size, rotation, pbs, isPhysical);
-        lock (m_prims) m_prims.Add(localID, prim);
+        lock (PhysObjects) PhysObjects.Add(localID, prim);
         return prim;
     }
 
     // This is a call from the simulator saying that some physical property has been updated.
-    // The BulletSim driver senses the changing of relevant properties so this taint 
+    // The BulletSim driver senses the changing of relevant properties so this taint
     // information call is not needed.
     public override void AddPhysicsActorTaint(PhysicsActor prim) { }
 
+    #endregion // Prim and Avatar addition and removal
+
+    #region Simulation
     // Simulate one timestep
     public override float Simulate(float timeStep)
     {
@@ -408,34 +472,46 @@ public class BSScene : PhysicsScene, IPhysicsParameters
         int collidersCount = 0;
         IntPtr collidersPtr;
 
-        LastSimulatedTimestep = timeStep;
+        int beforeTime = 0;
+        int simTime = 0;
 
         // prevent simulation until we've been initialized
-        if (!m_initialized) return 10.0f;
-
-        int simulateStartTime = Util.EnvironmentTickCount();
+        if (!m_initialized) return 5.0f;
 
         // update the prim states while we know the physics engine is not busy
+        int numTaints = _taintedObjects.Count;
         ProcessTaints();
 
         // Some of the prims operate with special vehicle properties
         ProcessVehicles(timeStep);
+        numTaints += _taintedObjects.Count;
         ProcessTaints();    // the vehicles might have added taints
 
         // step the physical world one interval
         m_simulationStep++;
         int numSubSteps = 0;
+
+        // DEBUG
+        // DetailLog("{0},BSScene.Simulate,beforeStep,ntaimts={1},step={2}", DetailLogZero, numTaints, m_simulationStep);
+
         try
         {
-            numSubSteps = BulletSimAPI.PhysicsStep(m_worldID, timeStep, m_maxSubSteps, m_fixedTimeStep,
+            if (PhysicsLogging.Enabled) beforeTime = Util.EnvironmentTickCount();
+
+            numSubSteps = BulletSimAPI.PhysicsStep(WorldID, timeStep, m_maxSubSteps, m_fixedTimeStep,
                         out updatedEntityCount, out updatedEntitiesPtr, out collidersCount, out collidersPtr);
-            // DetailLog("{0},Simulate,call, substeps={1}, updates={2}, colliders={3}", DetailLogZero, numSubSteps, updatedEntityCount, collidersCount); 
+
+            if (PhysicsLogging.Enabled) simTime = Util.EnvironmentTickCountSubtract(beforeTime);
+            DetailLog("{0},Simulate,call, frame={1}, nTaints={2}, simTime={3}, substeps={4}, updates={5}, colliders={6}",
+                        DetailLogZero, m_simulationStep, numTaints, simTime, numSubSteps, updatedEntityCount, collidersCount);
         }
         catch (Exception e)
         {
-            m_log.WarnFormat("{0},PhysicsStep Exception: substeps={1}, updates={2}, colliders={3}, e={4}", LogHeader, numSubSteps, updatedEntityCount, collidersCount, e);
-            // DetailLog("{0},PhysicsStepException,call, substeps={1}, updates={2}, colliders={3}", DetailLogZero, numSubSteps, updatedEntityCount, collidersCount);
-            // updatedEntityCount = 0;
+            m_log.WarnFormat("{0},PhysicsStep Exception: nTaints={1}, substeps={2}, updates={3}, colliders={4}, e={5}",
+                        LogHeader, numTaints, numSubSteps, updatedEntityCount, collidersCount, e);
+            DetailLog("{0},PhysicsStepException,call, nTaints={1}, substeps={2}, updates={3}, colliders={4}",
+                        DetailLogZero, numTaints, numSubSteps, updatedEntityCount, collidersCount);
+            updatedEntityCount = 0;
             collidersCount = 0;
         }
 
@@ -443,7 +519,7 @@ public class BSScene : PhysicsScene, IPhysicsParameters
         // Don't have to use the pointers passed back since we know it is the same pinned memory we passed in
 
         // Get a value for 'now' so all the collision and update routines don't have to get their own
-        m_simulationNowTime = Util.EnvironmentTickCount();
+        SimulationNowTime = Util.EnvironmentTickCount();
 
         // If there were collisions, process them by sending the event to the prim.
         // Collisions must be processed before updates.
@@ -460,21 +536,34 @@ public class BSScene : PhysicsScene, IPhysicsParameters
             }
         }
 
+        // This is a kludge to get avatar movement updates.
+        //   the simulator expects collisions for avatars even if there are have been no collisions. This updates
+        //   avatar animations and stuff.
+        // If you fix avatar animation updates, remove this overhead and let normal collision processing happen.
+        foreach (BSPhysObject bsp in m_avatars)
+            bsp.SendCollisions();
+
         // The above SendCollision's batch up the collisions on the objects.
         //      Now push the collisions into the simulator.
-        foreach (BSPrim bsp in m_primsWithCollisions)
-            bsp.SendCollisions();
-        m_primsWithCollisions.Clear();
+        if (ObjectsWithCollisions.Count > 0)
+        {
+            foreach (BSPhysObject bsp in ObjectsWithCollisions)
+                if (!m_avatars.Contains(bsp))   // don't call avatars twice
+                    if (!bsp.SendCollisions())
+                    {
+                        // If the object is done colliding, see that it's removed from the colliding list
+                        ObjectsWithNoMoreCollisions.Add(bsp);
+                    }
+        }
 
-        // This is a kludge to get avatar movement updated. 
-        //   Don't send collisions only if there were collisions -- send everytime.
-        //   ODE sends collisions even if there are none and this is used to update
-        //   avatar animations and stuff.
-        // foreach (BSCharacter bsc in m_avatarsWithCollisions)
-        //     bsc.SendCollisions();
-        foreach (KeyValuePair<uint, BSCharacter> kvp in m_avatars)
-            kvp.Value.SendCollisions();
-        m_avatarsWithCollisions.Clear();
+        // Objects that are done colliding are removed from the ObjectsWithCollisions list.
+        // Not done above because it is inside an iteration of ObjectWithCollisions.
+        if (ObjectsWithNoMoreCollisions.Count > 0)
+        {
+            foreach (BSPhysObject po in ObjectsWithNoMoreCollisions)
+                ObjectsWithCollisions.Remove(po);
+            ObjectsWithNoMoreCollisions.Clear();
+        }
 
         // If any of the objects had updated properties, tell the object it has been changed by the physics engine
         if (updatedEntityCount > 0)
@@ -482,145 +571,98 @@ public class BSScene : PhysicsScene, IPhysicsParameters
             for (int ii = 0; ii < updatedEntityCount; ii++)
             {
                 EntityProperties entprop = m_updateArray[ii];
-                BSPrim prim;
-                if (m_prims.TryGetValue(entprop.ID, out prim))
-                {
-                    prim.UpdateProperties(entprop);
-                    continue;
-                }
-                BSCharacter actor;
-                if (m_avatars.TryGetValue(entprop.ID, out actor))
+                BSPhysObject pobj;
+                if (PhysObjects.TryGetValue(entprop.ID, out pobj))
                 {
-                    actor.UpdateProperties(entprop);
-                    continue;
+                    pobj.UpdateProperties(entprop);
                 }
             }
         }
 
-        // If enabled, call into the physics engine to dump statistics
-        if (m_detailedStatsStep > 0)
-        {
-            if ((m_simulationStep % m_detailedStatsStep) == 0)
-            {
-                BulletSimAPI.DumpBulletStatistics();
-            }
-        }
-
-        // this is a waste since the outside routine also calcuates the physics simulation
-        //   period. TODO: There should be a way of computing physics frames from simulator computation.
-        // long simulateTotalTime = Util.EnvironmentTickCountSubtract(simulateStartTime);
-        // return (timeStep * (float)simulateTotalTime);
-
-        // TODO: FIX THIS: fps calculation possibly wrong.
-        // This calculation says 1/timeStep is the ideal frame rate. Any time added to
-        //    that by the physics simulation gives a slower frame rate.
-        long totalSimulationTime = Util.EnvironmentTickCountSubtract(simulateStartTime);
-        if (totalSimulationTime >= timeStep)
-            return 0;
-        return 1f / (timeStep + totalSimulationTime);
+        // The physics engine returns the number of milliseconds it simulated this call.
+        // These are summed and normalized to one second and divided by 1000 to give the reported physics FPS.
+        // We multiply by 45 to give a recognizable running rate (45 or less).
+        return numSubSteps * m_fixedTimeStep * 1000 * 45;
+        // return timeStep * 1000 * 45;
     }
 
     // Something has collided
-    private void SendCollision(uint localID, uint collidingWith, Vector3 collidePoint, Vector3 collideNormal, float penitration)
+    private void SendCollision(uint localID, uint collidingWith, Vector3 collidePoint, Vector3 collideNormal, float penetration)
     {
-        if (localID == TERRAIN_ID || localID == GROUNDPLANE_ID)
+        if (localID <= TerrainManager.HighestTerrainID)
         {
             return;         // don't send collisions to the terrain
         }
 
-        ActorTypes type = ActorTypes.Prim;
-        if (collidingWith == TERRAIN_ID || collidingWith == GROUNDPLANE_ID)
-            type = ActorTypes.Ground;
-        else if (m_avatars.ContainsKey(collidingWith))
-            type = ActorTypes.Agent;
-
-        BSPrim prim;
-        if (m_prims.TryGetValue(localID, out prim)) {
-            prim.Collide(collidingWith, type, collidePoint, collideNormal, penitration);
-            m_primsWithCollisions.Add(prim);
+        BSPhysObject collider;
+        if (!PhysObjects.TryGetValue(localID, out collider))
+        {
+            // If the object that is colliding cannot be found, just ignore the collision.
+            DetailLog("{0},BSScene.SendCollision,colliderNotInObjectList,id={1},with={2}", DetailLogZero, localID, collidingWith);
             return;
         }
-        BSCharacter actor;
-        if (m_avatars.TryGetValue(localID, out actor)) {
-            actor.Collide(collidingWith, type, collidePoint, collideNormal, penitration);
-            m_avatarsWithCollisions.Add(actor);
-            return;
+
+        // The terrain is not in the physical object list so 'collidee' can be null when Collide() is called.
+        BSPhysObject collidee = null;
+        PhysObjects.TryGetValue(collidingWith, out collidee);
+
+        // DetailLog("{0},BSScene.SendCollision,collide,id={1},with={2}", DetailLogZero, localID, collidingWith);
+
+        if (collider.Collide(collidingWith, collidee, collidePoint, collideNormal, penetration))
+        {
+            // If a collision was posted, remember to send it to the simulator
+            ObjectsWithCollisions.Add(collider);
         }
+
         return;
     }
 
-    public override void GetResults() { }
+    #endregion // Simulation
 
-    public override void SetTerrain(float[] heightMap) {
-        m_heightMap = heightMap;
-        this.TaintedObject("BSScene.SetTerrain", delegate()
-        {
-            BulletSimAPI.SetHeightmap(m_worldID, m_heightMap);
-        });
-    }
+    public override void GetResults() { }
 
-    // Someday we will have complex terrain with caves and tunnels
-    // For the moment, it's flat and convex
-    public float GetTerrainHeightAtXYZ(Vector3 loc)
-    {
-        return GetTerrainHeightAtXY(loc.X, loc.Y);
-    }
+    #region Terrain
 
-    public float GetTerrainHeightAtXY(float tX, float tY)
-    {
-        if (tX < 0 || tX >= Constants.RegionSize || tY < 0 || tY >= Constants.RegionSize)
-            return 30;
-        return m_heightMap[((int)tX) * Constants.RegionSize + ((int)tY)];
+    public override void SetTerrain(float[] heightMap) {
+        TerrainManager.SetTerrain(heightMap);
     }
 
-    public override void SetWaterLevel(float baseheight) 
+    public override void SetWaterLevel(float baseheight)
     {
         m_waterLevel = baseheight;
-        // TODO: pass to physics engine so things will float?
     }
-    public float GetWaterLevel()
+    // Someday....
+    public float GetWaterLevelAtXYZ(Vector3 loc)
     {
         return m_waterLevel;
     }
 
-    public override void DeleteTerrain() 
+    public override void DeleteTerrain()
     {
         // m_log.DebugFormat("{0}: DeleteTerrain()", LogHeader);
     }
 
-    public override void Dispose()
+    // Although no one seems to check this, I do support combining.
+    public override bool SupportsCombining()
     {
-        // m_log.DebugFormat("{0}: Dispose()", LogHeader);
-
-        // make sure no stepping happens while we're deleting stuff
-        m_initialized = false;
-
-        foreach (KeyValuePair<uint, BSCharacter> kvp in m_avatars)
-        {
-            kvp.Value.Destroy();
-        }
-        m_avatars.Clear();
-
-        foreach (KeyValuePair<uint, BSPrim> kvp in m_prims)
-        {
-            kvp.Value.Destroy();
-        }
-        m_prims.Clear();
-
-        // Now that the prims are all cleaned up, there should be no constraints left
-        if (m_constraintCollection != null)
-        {
-            m_constraintCollection.Dispose();
-            m_constraintCollection = null;
-        }
-
-        // Anything left in the unmanaged code should be cleaned out
-        BulletSimAPI.Shutdown(WorldID);
+        return TerrainManager.SupportsCombining();
+    }
+    // This call says I am a child to region zero in a mega-region. 'pScene' is that
+    //    of region zero, 'offset' is my offset from regions zero's origin, and
+    //    'extents' is the largest XY that is handled in my region.
+    public override void Combine(PhysicsScene pScene, Vector3 offset, Vector3 extents)
+    {
+        TerrainManager.Combine(pScene, offset, extents);
+    }
 
-        // Not logging any more
-        PhysicsLogging.Close();
+    // Unhook all the combining that I know about.
+    public override void UnCombine(PhysicsScene pScene)
+    {
+        TerrainManager.UnCombine(pScene);
     }
 
+    #endregion // Terrain
+
     public override Dictionary<uint, float> GetTopColliders()
     {
         return new Dictionary<uint, float>();
@@ -628,121 +670,6 @@ public class BSScene : PhysicsScene, IPhysicsParameters
 
     public override bool IsThreaded { get { return false;  } }
 
-    /// <summary>
-    /// Routine to figure out if we need to mesh this prim with our mesher
-    /// </summary>
-    /// <param name="pbs"></param>
-    /// <returns>true if the prim needs meshing</returns>
-    public bool NeedsMeshing(PrimitiveBaseShape pbs)
-    {
-        // most of this is redundant now as the mesher will return null if it cant mesh a prim
-        // but we still need to check for sculptie meshing being enabled so this is the most
-        // convenient place to do it for now...
-
-        // int iPropertiesNotSupportedDefault = 0;
-
-        if (pbs.SculptEntry && !_meshSculptedPrim)
-        {
-            // Render sculpties as boxes
-            return false;
-        }
-
-        // if it's a standard box or sphere with no cuts, hollows, twist or top shear, return false since Bullet 
-        // can use an internal representation for the prim
-        if (!_forceSimplePrimMeshing)
-        {
-            if ((pbs.ProfileShape == ProfileShape.Square && pbs.PathCurve == (byte)Extrusion.Straight)
-                || (pbs.ProfileShape == ProfileShape.HalfCircle && pbs.PathCurve == (byte)Extrusion.Curve1
-                        && pbs.Scale.X == pbs.Scale.Y && pbs.Scale.Y == pbs.Scale.Z))
-            {
-
-                if (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)
-                {
-                    return false;
-                }
-            }
-        }
-
-        /*  TODO: verify that the mesher will now do all these shapes
-        if (pbs.ProfileHollow != 0)
-            iPropertiesNotSupportedDefault++;
-
-        if ((pbs.PathBegin != 0) || pbs.PathEnd != 0)
-            iPropertiesNotSupportedDefault++;
-
-        if ((pbs.PathTwistBegin != 0) || (pbs.PathTwist != 0))
-            iPropertiesNotSupportedDefault++; 
-
-        if ((pbs.ProfileBegin != 0) || pbs.ProfileEnd != 0)
-            iPropertiesNotSupportedDefault++;
-
-        if ((pbs.PathScaleX != 100) || (pbs.PathScaleY != 100))
-            iPropertiesNotSupportedDefault++;
-
-        if ((pbs.PathShearX != 0) || (pbs.PathShearY != 0))
-            iPropertiesNotSupportedDefault++;
-
-        if (pbs.ProfileShape == ProfileShape.Circle && pbs.PathCurve == (byte)Extrusion.Straight)
-            iPropertiesNotSupportedDefault++;
-
-        if (pbs.ProfileShape == ProfileShape.HalfCircle && pbs.PathCurve == (byte)Extrusion.Curve1 && (pbs.Scale.X != pbs.Scale.Y || pbs.Scale.Y != pbs.Scale.Z || pbs.Scale.Z != pbs.Scale.X))
-            iPropertiesNotSupportedDefault++;
-
-        if (pbs.ProfileShape == ProfileShape.HalfCircle && pbs.PathCurve == (byte) Extrusion.Curve1)
-            iPropertiesNotSupportedDefault++;
-
-        // test for torus
-        if ((pbs.ProfileCurve & 0x07) == (byte)ProfileShape.Square)
-        {
-            if (pbs.PathCurve == (byte)Extrusion.Curve1)
-            {
-                iPropertiesNotSupportedDefault++;
-            }
-        }
-        else if ((pbs.ProfileCurve & 0x07) == (byte)ProfileShape.Circle)
-        {
-            if (pbs.PathCurve == (byte)Extrusion.Straight)
-            {
-                iPropertiesNotSupportedDefault++;
-            }
-            // ProfileCurve seems to combine hole shape and profile curve so we need to only compare against the lower 3 bits
-            else if (pbs.PathCurve == (byte)Extrusion.Curve1)
-            {
-                iPropertiesNotSupportedDefault++;
-            }
-        }
-        else if ((pbs.ProfileCurve & 0x07) == (byte)ProfileShape.HalfCircle)
-        {
-            if (pbs.PathCurve == (byte)Extrusion.Curve1 || pbs.PathCurve == (byte)Extrusion.Curve2)
-            {
-                iPropertiesNotSupportedDefault++;
-            }
-        }
-        else if ((pbs.ProfileCurve & 0x07) == (byte)ProfileShape.EquilateralTriangle)
-        {
-            if (pbs.PathCurve == (byte)Extrusion.Straight)
-            {
-                iPropertiesNotSupportedDefault++;
-            }
-            else if (pbs.PathCurve == (byte)Extrusion.Curve1)
-            {
-                iPropertiesNotSupportedDefault++;
-            }
-        }
-        if (iPropertiesNotSupportedDefault == 0)
-        {
-            return false;
-        }
-         */
-        return true; 
-    }
-
     // Calls to the PhysicsActors can't directly call into the physics engine
     // because it might be busy. We delay changes to a known time.
     // We rely on C#'s closure to save and restore the context for the delegate.
@@ -751,7 +678,10 @@ public class BSScene : PhysicsScene, IPhysicsParameters
         if (!m_initialized) return;
 
         lock (_taintLock)
+        {
             _taintedObjects.Add(new TaintCallbackEntry(ident, callback));
+        }
+
         return;
     }
 
@@ -763,6 +693,35 @@ public class BSScene : PhysicsScene, IPhysicsParameters
         if (_taintedObjects.Count > 0)  // save allocating new list if there is nothing to process
         {
             // swizzle a new list into the list location so we can process what's there
+            int taintCount = m_taintsToProcessPerStep;
+            TaintCallbackEntry oneCallback = new TaintCallbackEntry();
+            while (_taintedObjects.Count > 0 && taintCount-- > 0)
+            {
+                bool gotOne = false;
+                lock (_taintLock)
+                {
+                    if (_taintedObjects.Count > 0)
+                    {
+                        oneCallback = _taintedObjects[0];
+                        _taintedObjects.RemoveAt(0);
+                        gotOne = true;
+                    }
+                }
+                if (gotOne)
+                {
+                    try
+                    {
+                        DetailLog("{0},BSScene.ProcessTaints,doTaint,id={1}", DetailLogZero, oneCallback.ident); // DEBUG DEBUG DEBUG
+                        oneCallback.callback();
+                    }
+                    catch (Exception e)
+                    {
+                        m_log.ErrorFormat("{0}: ProcessTaints: {1}: Exception: {2}", LogHeader, oneCallback.ident, e);
+                    }
+                }
+            }
+            /*
+            // swizzle a new list into the list location so we can process what's there
             List<TaintCallbackEntry> oldList;
             lock (_taintLock)
             {
@@ -774,6 +733,7 @@ public class BSScene : PhysicsScene, IPhysicsParameters
             {
                 try
                 {
+                    DetailLog("{0},BSScene.ProcessTaints,doTaint,id={1}", DetailLogZero, tcbe.ident); // DEBUG DEBUG DEBUG
                     tcbe.callback();
                 }
                 catch (Exception e)
@@ -782,6 +742,7 @@ public class BSScene : PhysicsScene, IPhysicsParameters
                 }
             }
             oldList.Clear();
+             */
         }
     }
 
@@ -789,13 +750,10 @@ public class BSScene : PhysicsScene, IPhysicsParameters
 
     public void VehicleInSceneTypeChanged(BSPrim vehic, Vehicle newType)
     {
-        if (newType == Vehicle.TYPE_NONE)
-        {
-            RemoveVehiclePrim(vehic);
-        }
-        else
+        RemoveVehiclePrim(vehic);
+        if (newType != Vehicle.TYPE_NONE)
         {
-            // make it so the scene will call us each tick to do vehicle things
+           // make it so the scene will call us each tick to do vehicle things
            AddVehiclePrim(vehic);
         }
     }
@@ -827,17 +785,17 @@ public class BSScene : PhysicsScene, IPhysicsParameters
     }
 
     // Some prims have extra vehicle actions
-    // no locking because only called when physics engine is not busy
+    // Called at taint time!
     private void ProcessVehicles(float timeStep)
     {
-        foreach (BSPrim prim in m_vehicles)
+        foreach (BSPhysObject pobj in m_vehicles)
         {
-            prim.StepVehicle(timeStep);
+            pobj.StepVehicle(timeStep);
         }
     }
     #endregion Vehicles
 
-    #region Parameters
+    #region INI and command line parameter processing
 
     delegate void ParamUser(BSScene scene, IConfig conf, string paramName, float val);
     delegate float ParamGet(BSScene scene);
@@ -869,7 +827,7 @@ public class BSScene : PhysicsScene, IPhysicsParameters
     //    getters and setters.
     // It is easiest to find an existing definition and copy it.
     // Parameter values are floats. Booleans are converted to a floating value.
-    // 
+    //
     // A ParameterDefn() takes the following parameters:
     //    -- the text name of the parameter. This is used for console input and ini file.
     //    -- a short text description of the parameter. This shows up in the console listing.
@@ -888,25 +846,40 @@ public class BSScene : PhysicsScene, IPhysicsParameters
     {
         new ParameterDefn("MeshSculptedPrim", "Whether to create meshes for sculpties",
             ConfigurationParameters.numericTrue,
-            (s,cf,p,v) => { s._meshSculptedPrim = cf.GetBoolean(p, s.BoolNumeric(v)); },
-            (s) => { return s.NumericBool(s._meshSculptedPrim); },
-            (s,p,l,v) => { s._meshSculptedPrim = s.BoolNumeric(v); } ),
+            (s,cf,p,v) => { s.ShouldMeshSculptedPrim = cf.GetBoolean(p, s.BoolNumeric(v)); },
+            (s) => { return s.NumericBool(s.ShouldMeshSculptedPrim); },
+            (s,p,l,v) => { s.ShouldMeshSculptedPrim = s.BoolNumeric(v); } ),
         new ParameterDefn("ForceSimplePrimMeshing", "If true, only use primitive meshes for objects",
             ConfigurationParameters.numericFalse,
-            (s,cf,p,v) => { s._forceSimplePrimMeshing = cf.GetBoolean(p, s.BoolNumeric(v)); },
-            (s) => { return s.NumericBool(s._forceSimplePrimMeshing); },
-            (s,p,l,v) => { s._forceSimplePrimMeshing = s.BoolNumeric(v); } ),
+            (s,cf,p,v) => { s.ShouldForceSimplePrimMeshing = cf.GetBoolean(p, s.BoolNumeric(v)); },
+            (s) => { return s.NumericBool(s.ShouldForceSimplePrimMeshing); },
+            (s,p,l,v) => { s.ShouldForceSimplePrimMeshing = s.BoolNumeric(v); } ),
+        new ParameterDefn("UseHullsForPhysicalObjects", "If true, create hulls for physical objects",
+            ConfigurationParameters.numericTrue,
+            (s,cf,p,v) => { s.ShouldUseHullsForPhysicalObjects = cf.GetBoolean(p, s.BoolNumeric(v)); },
+            (s) => { return s.NumericBool(s.ShouldUseHullsForPhysicalObjects); },
+            (s,p,l,v) => { s.ShouldUseHullsForPhysicalObjects = s.BoolNumeric(v); } ),
 
-        new ParameterDefn("MeshLOD", "Level of detail to render meshes (32, 16, 8 or 4. 32=most detailed)",
+        new ParameterDefn("MeshLevelOfDetail", "Level of detail to render meshes (32, 16, 8 or 4. 32=most detailed)",
             8f,
-            (s,cf,p,v) => { s.m_meshLOD = cf.GetInt(p, (int)v); },
-            (s) => { return (float)s.m_meshLOD; },
-            (s,p,l,v) => { s.m_meshLOD = (int)v; } ),
-        new ParameterDefn("SculptLOD", "Level of detail to render sculpties (32, 16, 8 or 4. 32=most detailed)",
+            (s,cf,p,v) => { s.MeshLOD = (float)cf.GetInt(p, (int)v); },
+            (s) => { return s.MeshLOD; },
+            (s,p,l,v) => { s.MeshLOD = v; } ),
+        new ParameterDefn("MeshLevelOfDetailMegaPrim", "Level of detail to render meshes larger than threshold meters",
+            16f,
+            (s,cf,p,v) => { s.MeshMegaPrimLOD = (float)cf.GetInt(p, (int)v); },
+            (s) => { return s.MeshMegaPrimLOD; },
+            (s,p,l,v) => { s.MeshMegaPrimLOD = v; } ),
+        new ParameterDefn("MeshLevelOfDetailMegaPrimThreshold", "Size (in meters) of a mesh before using MeshMegaPrimLOD",
+            10f,
+            (s,cf,p,v) => { s.MeshMegaPrimThreshold = (float)cf.GetInt(p, (int)v); },
+            (s) => { return s.MeshMegaPrimThreshold; },
+            (s,p,l,v) => { s.MeshMegaPrimThreshold = v; } ),
+        new ParameterDefn("SculptLevelOfDetail", "Level of detail to render sculpties (32, 16, 8 or 4. 32=most detailed)",
             32f,
-            (s,cf,p,v) => { s.m_sculptLOD = cf.GetInt(p, (int)v); },
-            (s) => { return (float)s.m_sculptLOD; },
-            (s,p,l,v) => { s.m_sculptLOD = (int)v; } ),
+            (s,cf,p,v) => { s.SculptLOD = (float)cf.GetInt(p, (int)v); },
+            (s) => { return s.SculptLOD; },
+            (s,p,l,v) => { s.SculptLOD = v; } ),
 
         new ParameterDefn("MaxSubStep", "In simulation step, maximum number of substeps",
             10f,
@@ -928,11 +901,16 @@ public class BSScene : PhysicsScene, IPhysicsParameters
             (s,cf,p,v) => { s.m_maxUpdatesPerFrame = cf.GetInt(p, (int)v); },
             (s) => { return (float)s.m_maxUpdatesPerFrame; },
             (s,p,l,v) => { s.m_maxUpdatesPerFrame = (int)v; } ),
+        new ParameterDefn("MaxTaintsToProcessPerStep", "Number of update taints to process before each simulation step",
+            100f,
+            (s,cf,p,v) => { s.m_taintsToProcessPerStep = cf.GetInt(p, (int)v); },
+            (s) => { return (float)s.m_taintsToProcessPerStep; },
+            (s,p,l,v) => { s.m_taintsToProcessPerStep = (int)v; } ),
         new ParameterDefn("MaxObjectMass", "Maximum object mass (10000.01)",
             10000.01f,
-            (s,cf,p,v) => { s.m_maximumObjectMass = cf.GetFloat(p, v); },
-            (s) => { return (float)s.m_maximumObjectMass; },
-            (s,p,l,v) => { s.m_maximumObjectMass = v; } ),
+            (s,cf,p,v) => { s.MaximumObjectMass = cf.GetFloat(p, v); },
+            (s) => { return (float)s.MaximumObjectMass; },
+            (s,p,l,v) => { s.MaximumObjectMass = v; } ),
 
         new ParameterDefn("PID_D", "Derivitive factor for motion smoothing",
             2200f,
@@ -976,42 +954,42 @@ public class BSScene : PhysicsScene, IPhysicsParameters
             0f,
             (s,cf,p,v) => { s.m_params[0].linearDamping = cf.GetFloat(p, v); },
             (s) => { return s.m_params[0].linearDamping; },
-            (s,p,l,v) => { s.UpdateParameterPrims(ref s.m_params[0].linearDamping, p, l, v); } ),
+            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].linearDamping, p, l, v); } ),
         new ParameterDefn("AngularDamping", "Factor to damp angular movement per second (0.0 - 1.0)",
             0f,
             (s,cf,p,v) => { s.m_params[0].angularDamping = cf.GetFloat(p, v); },
             (s) => { return s.m_params[0].angularDamping; },
-            (s,p,l,v) => { s.UpdateParameterPrims(ref s.m_params[0].angularDamping, p, l, v); } ),
+            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].angularDamping, p, l, v); } ),
         new ParameterDefn("DeactivationTime", "Seconds before considering an object potentially static",
             0.2f,
             (s,cf,p,v) => { s.m_params[0].deactivationTime = cf.GetFloat(p, v); },
             (s) => { return s.m_params[0].deactivationTime; },
-            (s,p,l,v) => { s.UpdateParameterPrims(ref s.m_params[0].deactivationTime, p, l, v); } ),
+            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].deactivationTime, p, l, v); } ),
         new ParameterDefn("LinearSleepingThreshold", "Seconds to measure linear movement before considering static",
             0.8f,
             (s,cf,p,v) => { s.m_params[0].linearSleepingThreshold = cf.GetFloat(p, v); },
             (s) => { return s.m_params[0].linearSleepingThreshold; },
-            (s,p,l,v) => { s.UpdateParameterPrims(ref s.m_params[0].linearSleepingThreshold, p, l, v); } ),
+            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].linearSleepingThreshold, p, l, v); } ),
         new ParameterDefn("AngularSleepingThreshold", "Seconds to measure angular movement before considering static",
             1.0f,
             (s,cf,p,v) => { s.m_params[0].angularSleepingThreshold = cf.GetFloat(p, v); },
             (s) => { return s.m_params[0].angularSleepingThreshold; },
-            (s,p,l,v) => { s.UpdateParameterPrims(ref s.m_params[0].angularSleepingThreshold, p, l, v); } ),
+            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].angularSleepingThreshold, p, l, v); } ),
         new ParameterDefn("CcdMotionThreshold", "Continuious collision detection threshold (0 means no CCD)" ,
             0f,     // set to zero to disable
             (s,cf,p,v) => { s.m_params[0].ccdMotionThreshold = cf.GetFloat(p, v); },
             (s) => { return s.m_params[0].ccdMotionThreshold; },
-            (s,p,l,v) => { s.UpdateParameterPrims(ref s.m_params[0].ccdMotionThreshold, p, l, v); } ),
+            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].ccdMotionThreshold, p, l, v); } ),
         new ParameterDefn("CcdSweptSphereRadius", "Continuious collision detection test radius" ,
             0f,
             (s,cf,p,v) => { s.m_params[0].ccdSweptSphereRadius = cf.GetFloat(p, v); },
             (s) => { return s.m_params[0].ccdSweptSphereRadius; },
-            (s,p,l,v) => { s.UpdateParameterPrims(ref s.m_params[0].ccdSweptSphereRadius, p, l, v); } ),
+            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].ccdSweptSphereRadius, p, l, v); } ),
         new ParameterDefn("ContactProcessingThreshold", "Distance between contacts before doing collision check" ,
             0.1f,
             (s,cf,p,v) => { s.m_params[0].contactProcessingThreshold = cf.GetFloat(p, v); },
             (s) => { return s.m_params[0].contactProcessingThreshold; },
-            (s,p,l,v) => { s.UpdateParameterPrims(ref s.m_params[0].contactProcessingThreshold, p, l, v); } ),
+            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].contactProcessingThreshold, p, l, v); } ),
 
         new ParameterDefn("TerrainFriction", "Factor to reduce movement against terrain surface" ,
             0.5f,
@@ -1029,44 +1007,44 @@ public class BSScene : PhysicsScene, IPhysicsParameters
             (s) => { return s.m_params[0].terrainRestitution; },
             (s,p,l,v) => { s.m_params[0].terrainRestitution = v; s.TaintedUpdateParameter(p,l,v); } ),
         new ParameterDefn("AvatarFriction", "Factor to reduce movement against an avatar. Changed on avatar recreation.",
-            0.5f,
+            0.2f,
             (s,cf,p,v) => { s.m_params[0].avatarFriction = cf.GetFloat(p, v); },
             (s) => { return s.m_params[0].avatarFriction; },
-            (s,p,l,v) => { s.UpdateParameterAvatars(ref s.m_params[0].avatarFriction, p, l, v); } ),
+            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].avatarFriction, p, l, v); } ),
         new ParameterDefn("AvatarDensity", "Density of an avatar. Changed on avatar recreation.",
             60f,
             (s,cf,p,v) => { s.m_params[0].avatarDensity = cf.GetFloat(p, v); },
             (s) => { return s.m_params[0].avatarDensity; },
-            (s,p,l,v) => { s.UpdateParameterAvatars(ref s.m_params[0].avatarDensity, p, l, v); } ),
+            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].avatarDensity, p, l, v); } ),
         new ParameterDefn("AvatarRestitution", "Bouncyness. Changed on avatar recreation.",
             0f,
             (s,cf,p,v) => { s.m_params[0].avatarRestitution = cf.GetFloat(p, v); },
             (s) => { return s.m_params[0].avatarRestitution; },
-            (s,p,l,v) => { s.UpdateParameterAvatars(ref s.m_params[0].avatarRestitution, p, l, v); } ),
+            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].avatarRestitution, p, l, v); } ),
         new ParameterDefn("AvatarCapsuleRadius", "Radius of space around an avatar",
             0.37f,
             (s,cf,p,v) => { s.m_params[0].avatarCapsuleRadius = cf.GetFloat(p, v); },
             (s) => { return s.m_params[0].avatarCapsuleRadius; },
-            (s,p,l,v) => { s.UpdateParameterAvatars(ref s.m_params[0].avatarCapsuleRadius, p, l, v); } ),
+            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].avatarCapsuleRadius, p, l, v); } ),
         new ParameterDefn("AvatarCapsuleHeight", "Default height of space around avatar",
             1.5f,
             (s,cf,p,v) => { s.m_params[0].avatarCapsuleHeight = cf.GetFloat(p, v); },
             (s) => { return s.m_params[0].avatarCapsuleHeight; },
-            (s,p,l,v) => { s.UpdateParameterAvatars(ref s.m_params[0].avatarCapsuleHeight, p, l, v); } ),
+            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].avatarCapsuleHeight, p, l, v); } ),
             new ParameterDefn("AvatarContactProcessingThreshold", "Distance from capsule to check for collisions",
             0.1f,
             (s,cf,p,v) => { s.m_params[0].avatarContactProcessingThreshold = cf.GetFloat(p, v); },
             (s) => { return s.m_params[0].avatarContactProcessingThreshold; },
-            (s,p,l,v) => { s.UpdateParameterAvatars(ref s.m_params[0].avatarContactProcessingThreshold, p, l, v); } ),
+            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].avatarContactProcessingThreshold, p, l, v); } ),
 
 
             new ParameterDefn("MaxPersistantManifoldPoolSize", "Number of manifolds pooled (0 means default of 4096)",
-            0f,     // zero to disable
+            0f,
             (s,cf,p,v) => { s.m_params[0].maxPersistantManifoldPoolSize = cf.GetFloat(p, v); },
             (s) => { return s.m_params[0].maxPersistantManifoldPoolSize; },
             (s,p,l,v) => { s.m_params[0].maxPersistantManifoldPoolSize = v; } ),
             new ParameterDefn("MaxCollisionAlgorithmPoolSize", "Number of collisions pooled (0 means default of 4096)",
-            0f,     // zero to disable
+            0f,
             (s,cf,p,v) => { s.m_params[0].maxCollisionAlgorithmPoolSize = cf.GetFloat(p, v); },
             (s) => { return s.m_params[0].maxCollisionAlgorithmPoolSize; },
             (s,p,l,v) => { s.m_params[0].maxCollisionAlgorithmPoolSize = v; } ),
@@ -1081,12 +1059,12 @@ public class BSScene : PhysicsScene, IPhysicsParameters
             (s) => { return s.m_params[0].shouldForceUpdateAllAabbs; },
             (s,p,l,v) => { s.m_params[0].shouldForceUpdateAllAabbs = v; } ),
             new ParameterDefn("ShouldRandomizeSolverOrder", "Enable for slightly better stacking interaction",
-            ConfigurationParameters.numericFalse,
+            ConfigurationParameters.numericTrue,
             (s,cf,p,v) => { s.m_params[0].shouldRandomizeSolverOrder = s.NumericBool(cf.GetBoolean(p, s.BoolNumeric(v))); },
             (s) => { return s.m_params[0].shouldRandomizeSolverOrder; },
             (s,p,l,v) => { s.m_params[0].shouldRandomizeSolverOrder = v; } ),
             new ParameterDefn("ShouldSplitSimulationIslands", "Enable splitting active object scanning islands",
-            ConfigurationParameters.numericFalse,
+            ConfigurationParameters.numericTrue,
             (s,cf,p,v) => { s.m_params[0].shouldSplitSimulationIslands = s.NumericBool(cf.GetBoolean(p, s.BoolNumeric(v))); },
             (s) => { return s.m_params[0].shouldSplitSimulationIslands; },
             (s,p,l,v) => { s.m_params[0].shouldSplitSimulationIslands = v; } ),
@@ -1121,28 +1099,27 @@ public class BSScene : PhysicsScene, IPhysicsParameters
             (s,cf,p,v) => { s.m_params[0].linkConstraintTransMotorMaxForce = cf.GetFloat(p, v); },
             (s) => { return s.m_params[0].linkConstraintTransMotorMaxForce; },
             (s,p,l,v) => { s.m_params[0].linkConstraintTransMotorMaxForce = v; } ),
-            new ParameterDefn("LinkConstraintCFM", "Amount constraint can be violated. 0=none, 1=all. Default=0",
-            0.0f,
+            new ParameterDefn("LinkConstraintCFM", "Amount constraint can be violated. 0=no violation, 1=infinite. Default=0.1",
+            0.001f,
             (s,cf,p,v) => { s.m_params[0].linkConstraintCFM = cf.GetFloat(p, v); },
             (s) => { return s.m_params[0].linkConstraintCFM; },
             (s,p,l,v) => { s.m_params[0].linkConstraintCFM = v; } ),
             new ParameterDefn("LinkConstraintERP", "Amount constraint is corrected each tick. 0=none, 1=all. Default = 0.2",
-            0.2f,
+            0.8f,
             (s,cf,p,v) => { s.m_params[0].linkConstraintERP = cf.GetFloat(p, v); },
             (s) => { return s.m_params[0].linkConstraintERP; },
             (s,p,l,v) => { s.m_params[0].linkConstraintERP = v; } ),
+            new ParameterDefn("LinkConstraintSolverIterations", "Number of solver iterations when computing constraint. (0 = Bullet default)",
+            40,
+            (s,cf,p,v) => { s.m_params[0].linkConstraintSolverIterations = cf.GetFloat(p, v); },
+            (s) => { return s.m_params[0].linkConstraintSolverIterations; },
+            (s,p,l,v) => { s.m_params[0].linkConstraintSolverIterations = v; } ),
 
-        new ParameterDefn("DetailedStats", "Frames between outputting detailed phys stats. (0 is off)",
+        new ParameterDefn("LogPhysicsStatisticsFrames", "Frames between outputting detailed phys stats. (0 is off)",
             0f,
-            (s,cf,p,v) => { s.m_detailedStatsStep = cf.GetInt(p, (int)v); },
-            (s) => { return (float)s.m_detailedStatsStep; },
-            (s,p,l,v) => { s.m_detailedStatsStep = (int)v; } ),
-        new ParameterDefn("ShouldDebugLog", "Enables detailed DEBUG log statements",
-            ConfigurationParameters.numericFalse,
-            (s,cf,p,v) => { s.ShouldDebugLog = cf.GetBoolean(p, s.BoolNumeric(v)); },
-            (s) => { return s.NumericBool(s.ShouldDebugLog); },
-            (s,p,l,v) => { s.ShouldDebugLog = s.BoolNumeric(v); } ),
-
+            (s,cf,p,v) => { s.m_params[0].physicsLoggingFrames = cf.GetInt(p, (int)v); },
+            (s) => { return (float)s.m_params[0].physicsLoggingFrames; },
+            (s,p,l,v) => { s.m_params[0].physicsLoggingFrames = (int)v; } ),
     };
 
     // Convert a boolean to our numeric true and false values
@@ -1200,11 +1177,12 @@ public class BSScene : PhysicsScene, IPhysicsParameters
 
     private PhysParameterEntry[] SettableParameters = new PhysParameterEntry[1];
 
+    // This creates an array in the correct format for returning the list of
+    //    parameters. This is used by the 'list' option of the 'physics' command.
     private void BuildParameterTable()
     {
         if (SettableParameters.Length < ParameterDefinitions.Length)
         {
-
             List<PhysParameterEntry> entries = new List<PhysParameterEntry>();
             for (int ii = 0; ii < ParameterDefinitions.Length; ii++)
             {
@@ -1250,18 +1228,10 @@ public class BSScene : PhysicsScene, IPhysicsParameters
     }
 
     // check to see if we are updating a parameter for a particular or all of the prims
-    protected void UpdateParameterPrims(ref float loc, string parm, uint localID, float val)
-    {
-        List<uint> operateOn;
-        lock (m_prims) operateOn = new List<uint>(m_prims.Keys);
-        UpdateParameterSet(operateOn, ref loc, parm, localID, val);
-    }
-
-    // check to see if we are updating a parameter for a particular or all of the avatars
-    protected void UpdateParameterAvatars(ref float loc, string parm, uint localID, float val)
+    protected void UpdateParameterObject(ref float loc, string parm, uint localID, float val)
     {
         List<uint> operateOn;
-        lock (m_avatars) operateOn = new List<uint>(m_avatars.Keys);
+        lock (PhysObjects) operateOn = new List<uint>(PhysObjects.Keys);
         UpdateParameterSet(operateOn, ref loc, parm, localID, val);
     }
 
@@ -1284,11 +1254,11 @@ public class BSScene : PhysicsScene, IPhysicsParameters
                 TaintedObject("BSScene.UpdateParameterSet", delegate() {
                     foreach (uint lID in objectIDs)
                     {
-                        BulletSimAPI.UpdateParameter(m_worldID, lID, xparm, xval);
+                        BulletSimAPI.UpdateParameter(WorldID, lID, xparm, xval);
                     }
                 });
                 break;
-            default: 
+            default:
                 // setting only one localID
                 TaintedUpdateParameter(parm, localID, val);
                 break;
@@ -1302,7 +1272,7 @@ public class BSScene : PhysicsScene, IPhysicsParameters
         string xparm = parm.ToLower();
         float xval = val;
         TaintedObject("BSScene.TaintedUpdateParameter", delegate() {
-            BulletSimAPI.UpdateParameter(m_worldID, xlocalID, xparm, xval);
+            BulletSimAPI.UpdateParameter(WorldID, xlocalID, xparm, xval);
         });
     }
 
@@ -1330,6 +1300,8 @@ public class BSScene : PhysicsScene, IPhysicsParameters
     public void DetailLog(string msg, params Object[] args)
     {
         PhysicsLogging.Write(msg, args);
+        // Add the Flush() if debugging crashes to get all the messages written out.
+        // PhysicsLogging.Flush();
     }
     // used to fill in the LocalID when there isn't one
     public const string DetailLogZero = "0000000000";