1 files changed, 44 insertions, 27 deletions

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
index 26b8df5..159f79f 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
@@ -115,6 +115,8 @@ public sealed class BSPrim : BSPhysObject
         PhysBody = new BulletBody(LocalID);
         PhysShape = new BulletShape();
 
+        Linkset.Refresh(this);
+
         DetailLog("{0},BSPrim.constructor,call", LocalID);
         // do the actual object creation at taint time
         PhysicsScene.TaintedObject("BSPrim.create", delegate()
@@ -384,13 +386,13 @@ public sealed class BSPrim : BSPhysObject
     }
 
     // Return the effective mass of the object.
-    // If there are multiple items in the linkset, add them together for the root
+        // The definition of this call is to return the mass of the prim.
+        // If the simulator cares about the mass of the linkset, it will sum it itself.
     public override float Mass
     {
         get
         {
-            return Linkset.LinksetMass;
-            // return _mass;
+            return _mass;
         }
     }
 
@@ -400,22 +402,41 @@ public sealed class BSPrim : BSPhysObject
     }
     // Set the physical mass to the passed mass.
     // Note that this does not change _mass!
-    public override void UpdatePhysicalMassProperties(float physMass)
+    public override void UpdatePhysicalMassProperties(float physMass, bool inWorld)
     {
-        if (IsStatic)
+        if (PhysBody.HasPhysicalBody)
         {
-            Inertia = OMV.Vector3.Zero;
-            BulletSimAPI.SetMassProps2(PhysBody.ptr, 0f, Inertia);
-            BulletSimAPI.UpdateInertiaTensor2(PhysBody.ptr);
-        }
-        else
-        {
-            Inertia = BulletSimAPI.CalculateLocalInertia2(PhysShape.ptr, physMass);
-            BulletSimAPI.SetMassProps2(PhysBody.ptr, physMass, Inertia);
-            BulletSimAPI.UpdateInertiaTensor2(PhysBody.ptr);
-            // center of mass is at the zero of the object
-            // DEBUG DEBUG BulletSimAPI.SetCenterOfMassByPosRot2(PhysBody.ptr, ForcePosition, ForceOrientation);
-            DetailLog("{0},BSPrim.UpdateMassProperties,mass={1},localInertia={2}", LocalID, physMass, Inertia);
+            if (IsStatic)
+            {
+                Inertia = OMV.Vector3.Zero;
+                BulletSimAPI.SetMassProps2(PhysBody.ptr, 0f, Inertia);
+                BulletSimAPI.UpdateInertiaTensor2(PhysBody.ptr);
+            }
+            else
+            {
+                if (inWorld)
+                {
+                    // Changing interesting properties doesn't change proxy and collision cache
+                    //    information. The Bullet solution is to re-add the object to the world
+                    //    after parameters are changed.
+                    BulletSimAPI.RemoveObjectFromWorld2(PhysicsScene.World.ptr, PhysBody.ptr);
+                }
+
+                float grav = PhysicsScene.Params.gravity * (1f - _buoyancy);
+                BulletSimAPI.SetGravity2(PhysBody.ptr, new OMV.Vector3(0f, 0f, grav));
+
+                Inertia = BulletSimAPI.CalculateLocalInertia2(PhysShape.ptr, physMass);
+                BulletSimAPI.SetMassProps2(PhysBody.ptr, physMass, Inertia);
+                BulletSimAPI.UpdateInertiaTensor2(PhysBody.ptr);
+                // center of mass is at the zero of the object
+                // DEBUG DEBUG BulletSimAPI.SetCenterOfMassByPosRot2(PhysBody.ptr, ForcePosition, ForceOrientation);
+                DetailLog("{0},BSPrim.UpdateMassProperties,mass={1},localInertia={2}", LocalID, physMass, Inertia);
+
+                if (inWorld)
+                {
+                    BulletSimAPI.AddObjectToWorld2(PhysicsScene.World.ptr, PhysBody.ptr);
+                }
+            }
         }
     }
 
@@ -714,7 +735,7 @@ public sealed class BSPrim : BSPhysObject
         Linkset.Refresh(this);
 
         DetailLog("{0},BSPrim.UpdatePhysicalParameters,taintExit,static={1},solid={2},mass={3},collide={4},cf={5:X},body={6},shape={7}",
-                        LocalID, IsStatic, IsSolid, _mass, SubscribedEvents(), CurrentCollisionFlags, PhysBody, PhysShape);
+                        LocalID, IsStatic, IsSolid, Mass, SubscribedEvents(), CurrentCollisionFlags, PhysBody, PhysShape);
     }
 
     // "Making dynamic" means changing to and from static.
@@ -737,7 +758,7 @@ public sealed class BSPrim : BSPhysObject
             BulletSimAPI.SetRestitution2(PhysBody.ptr, matAttrib.restitution);
 
             // Mass is zero which disables a bunch of physics stuff in Bullet
-            UpdatePhysicalMassProperties(0f);
+            UpdatePhysicalMassProperties(0f, false);
             // Set collision detection parameters
             if (BSParam.CcdMotionThreshold > 0f)
             {
@@ -777,7 +798,7 @@ public sealed class BSPrim : BSPhysObject
             // DEBUG DEBUG BulletSimAPI.SetCenterOfMassByPosRot2(Linkset.LinksetRoot.PhysBody.ptr, _position, _orientation);
 
             // A dynamic object has mass
-            UpdatePhysicalMassProperties(RawMass);
+            UpdatePhysicalMassProperties(RawMass, false);
 
             // Set collision detection parameters
             if (BSParam.CcdMotionThreshold > 0f)
@@ -950,13 +971,9 @@ public sealed class BSPrim : BSPhysObject
         set {
             _buoyancy = value;
             // DetailLog("{0},BSPrim.setForceBuoyancy,taint,buoy={1}", LocalID, _buoyancy);
-            // Buoyancy is faked by changing the gravity applied to the object
-            if (PhysBody.HasPhysicalBody)
-            {
-                float grav = PhysicsScene.Params.gravity * (1f - _buoyancy);
-                BulletSimAPI.SetGravity2(PhysBody.ptr, new OMV.Vector3(0f, 0f, grav));
-                ActivateIfPhysical(false);
-            }
+            // Force the recalculation of the various inertia,etc variables in the object
+            UpdatePhysicalMassProperties(_mass, true);
+            ActivateIfPhysical(false);
         }
     }