* Performance Changes:

* Moves Entity Updates into a seperate thread, allowing for OpenSim to utilize a computers CPU more effectively in return for potentially greater user and prim capacity.
* Removes an expensive Sqrt call performed during Update on each object. This should lower CPU requirements for high-prim regions with physics enabled.
* MXP Changes: Centers the region around 0,0 for primitives instead of 128,128. Prim display should now look more correct for MXP viewers.

OpenSim/Client/MXP/ClientStack/MXPClientView.cs

@@ -577,7 +577,9 @@ namespace OpenSim.Client.MXP.ClientStack
             pe.ObjectFragment.AngularAcceleration = new float[4];
             pe.ObjectFragment.AngularVelocity = new float[] { rvel.X, rvel.Y, rvel.Z, 0.0f };
             pe.ObjectFragment.BoundingSphereRadius = primShape.Scale.Length()/2.0f;
-            pe.ObjectFragment.Location = new float[] { pos.X, pos.Y, pos.Z };
+
+            pe.ObjectFragment.Location = new float[] { pos.X - 120.0f, pos.Z, pos.Y - 128.0f };
+
             pe.ObjectFragment.Mass = 1.0f;
             pe.ObjectFragment.ObjectId = objectID.Guid;
             pe.ObjectFragment.Orientation = new float[] { rotation.X, rotation.Y, rotation.Z, rotation.W };

OpenSim/Framework/Util.cs

@@ -88,6 +88,21 @@ namespace OpenSim.Framework
             return Math.Sqrt(dx * dx + dy * dy + dz * dz);
         }
 
+        /// <summary>
+        /// Returns true if the distance beween A and B is less than amount. Significantly faster than GetDistanceTo since it eliminates the Sqrt.
+        /// </summary>
+        /// <param name="a"></param>
+        /// <param name="b"></param>
+        /// <param name="amount"></param>
+        /// <returns></returns>
+        public static bool DistanceLessThan(Vector3 a, Vector3 b, double amount)
+        {
+            float dx = a.X - b.X;
+            float dy = a.Y - b.Y;
+            float dz = a.Z - b.Z;
+            return (dx*dx + dy*dy + dz*dz) < (amount*amount);           
+        }
+
         /// <summary>
         /// Get the magnitude of a 3d vector
         /// </summary>

OpenSim/Region/Framework/Scenes/Scene.cs

@@ -64,6 +64,8 @@ namespace OpenSim.Region.Framework.Scenes
 
         protected Timer m_restartWaitTimer = new Timer();
 
+        protected Thread m_updateEntitiesThread;
+
         public SimStatsReporter StatsReporter;
 
         protected List<RegionInfo> m_regionRestartNotifyList = new List<RegionInfo>();
@@ -852,7 +854,19 @@ namespace OpenSim.Region.Framework.Scenes
                     otherMS = Environment.TickCount;
                     // run through all entities looking for updates (slow)
                     if (m_frame % m_update_entities == 0)
-                        m_sceneGraph.UpdateEntities();
+                    {
+                        if (m_updateEntitiesThread == null)
+                        {
+                            m_updateEntitiesThread = new Thread(m_sceneGraph.UpdateEntities);
+                            ThreadTracker.Add(m_updateEntitiesThread);
+                        }
+
+                        if(!m_updateEntitiesThread.IsAlive)
+                            m_updateEntitiesThread.Start();
+
+                        //m_sceneGraph.UpdateEntities();
+                    }
+                        
 
                     // run through entities that have scheduled themselves for
                     // updates looking for updates(faster)

OpenSim/Region/Framework/Scenes/SceneObjectGroup.cs

@@ -1733,12 +1733,12 @@ namespace OpenSim.Region.Framework.Scenes
                     //return;
                 //}
 
-                if ((Util.GetDistanceTo(lastPhysGroupPos, AbsolutePosition) > 0.02) && UsePhysics)
+                if (Util.DistanceLessThan(lastPhysGroupPos, AbsolutePosition, 0.02) && UsePhysics)
                 {
                     m_rootPart.UpdateFlag = 1;
                     lastPhysGroupPos = AbsolutePosition;
                 }
-                    //foreach (SceneObjectPart part in m_parts.Values)
+                //foreach (SceneObjectPart part in m_parts.Values)
                     //{
                         //if (part.UpdateFlag == 0) part.UpdateFlag = 1;
                     //}