BulletSim: disable center-of-mass computation for linksets until debugged. Move physical prim above ground if it is underground. Previously tried to correct by applying and up force but the prim would never go through the ground.

2 files changed, 36 insertions, 25 deletions

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs b/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs
index ad8024c..5a1b5c7 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs
@@ -319,6 +319,7 @@ public sealed class BSLinksetCompound : BSLinkset
     // Constraint linksets are rebuilt every time.
     // Note that this works for rebuilding just the root after a linkset is taken apart.
     // Called at taint time!!
+    private bool disableCOM = true;     // disable until we get this debugged
     private void RecomputeLinksetCompound()
     {
         try
@@ -331,15 +332,26 @@ public sealed class BSLinksetCompound : BSLinkset
 
             // The center of mass for the linkset is the geometric center of the group.
             // Compute a displacement for each component so it is relative to the center-of-mass.
-            OMV.Vector3 centerOfMass = ComputeLinksetGeometricCenter();
-            OMV.Vector3 centerDisplacement = centerOfMass - LinksetRoot.RawPosition;
+            // Bullet presumes an object's origin (relative <0,0,0>) is its center-of-mass
+            OMV.Vector3 centerOfMass;
+            OMV.Vector3 centerDisplacement = OMV.Vector3.Zero;
+            if (disableCOM)                             // DEBUG DEBUG
+            {                                           // DEBUG DEBUG
+                centerOfMass = LinksetRoot.RawPosition; // DEBUG DEBUG
+                LinksetRoot.PositionDisplacement = OMV.Vector3.Zero;
+            }                                           // DEBUG DEBUG
+            else
+            {
+                centerOfMass = ComputeLinksetGeometricCenter();
+                centerDisplacement = centerOfMass - LinksetRoot.RawPosition;
 
-            // Since we're displacing the center of the shape, we need to move the body in the world
-            LinksetRoot.PositionDisplacement = centerDisplacement * LinksetRoot.RawOrientation;
+                // Since we're displacing the center of the shape, we need to move the body in the world
+                LinksetRoot.PositionDisplacement = centerDisplacement;
 
-            PhysicsScene.PE.UpdateChildTransform(LinksetRoot.PhysShape, 0, -centerDisplacement, OMV.Quaternion.Identity, false);
-            DetailLog("{0},BSLinksetCompound.RecomputeLinksetCompound,COM,com={1},rootPos={2},centerDisp={3}",
-                                    LinksetRoot.LocalID, centerOfMass, LinksetRoot.RawPosition, centerDisplacement);
+                PhysicsScene.PE.UpdateChildTransform(LinksetRoot.PhysShape, 0, -centerDisplacement, OMV.Quaternion.Identity, false);
+                DetailLog("{0},BSLinksetCompound.RecomputeLinksetCompound,COM,com={1},rootPos={2},centerDisp={3}",
+                                        LinksetRoot.LocalID, centerOfMass, LinksetRoot.RawPosition, centerDisplacement);
+            }
 
             DetailLog("{0},BSLinksetCompound.RecomputeLinksetCompound,start,rBody={1},rShape={2},numChildren={3}",
                             LinksetRoot.LocalID, LinksetRoot.PhysBody, LinksetRoot.PhysShape, NumberOfChildren);
@@ -357,14 +369,15 @@ public sealed class BSLinksetCompound : BSLinkset
                     BSLinksetCompoundInfo lci = cPrim.LinksetInfo as BSLinksetCompoundInfo;
                     if (lci == null)
                     {
-                        // Each child position and rotation is given relative to the root.
+                        // Each child position and rotation is given relative to the center-of-mass.
                         OMV.Quaternion invRootOrientation = OMV.Quaternion.Inverse(LinksetRoot.RawOrientation);
-                        OMV.Vector3 displacementPos = (cPrim.RawPosition - LinksetRoot.RawPosition) * invRootOrientation;
+                        OMV.Vector3 displacementFromRoot = (cPrim.RawPosition - LinksetRoot.RawPosition) * invRootOrientation;
+                        OMV.Vector3 displacementFromCOM = displacementFromRoot - centerDisplacement;
                         OMV.Quaternion displacementRot = cPrim.RawOrientation * invRootOrientation;
 
                         // Save relative position for recomputing child's world position after moving linkset.
-                        lci = new BSLinksetCompoundInfo(memberIndex, displacementPos, displacementRot);
-                        lci.OffsetFromCenterOfMass = displacementPos - centerDisplacement;
+                        lci = new BSLinksetCompoundInfo(memberIndex, displacementFromCOM, displacementRot);
+                        lci.OffsetFromRoot = displacementFromRoot;
                         cPrim.LinksetInfo = lci;
                         DetailLog("{0},BSLinksetCompound.RecomputeLinksetCompound,creatingRelPos,lci={1}", cPrim.LocalID, lci);
                     }
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
index 003dc54..e5f7ab7 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
@@ -297,7 +297,7 @@ public sealed class BSPrim : BSPhysObject
             */
 
             // don't do the GetObjectPosition for root elements because this function is called a zillion times.
-            // _position = PhysicsScene.PE.GetObjectPosition2(PhysicsScene.World, BSBody);
+            // _position = PhysicsScene.PE.GetObjectPosition2(PhysicsScene.World, BSBody) - PositionDisplacement;
             return _position;
         }
         set {
@@ -362,7 +362,7 @@ public sealed class BSPrim : BSPhysObject
     {
         bool ret = false;
 
-        if (!PhysicsScene.TerrainManager.IsWithinKnownTerrain(_position))
+        if (!PhysicsScene.TerrainManager.IsWithinKnownTerrain(RawPosition))
         {
             // The physical object is out of the known/simulated area.
             // Upper levels of code will handle the transition to other areas so, for
@@ -376,8 +376,11 @@ public sealed class BSPrim : BSPhysObject
         {
             DetailLog("{0},BSPrim.PositionAdjustUnderGround,call,pos={1},terrain={2}", LocalID, _position, terrainHeight);
             float targetHeight = terrainHeight + (Size.Z / 2f);
-            // Upforce proportional to the distance away from the terrain. Correct the error in 1 sec.
-            upForce.Z = (terrainHeight - RawPosition.Z) * 1f;
+            // If the object is below ground it just has to be moved up because pushing will
+            //     not get it through the terrain
+            _position.Z = targetHeight;
+            if (!inTaintTime)
+                ForcePosition = _position;
             ret = true;
         }
 
@@ -389,20 +392,15 @@ public sealed class BSPrim : BSPhysObject
             {
                 // Upforce proportional to the distance away from the water. Correct the error in 1 sec.
                 upForce.Z = (waterHeight - RawPosition.Z) * 1f;
+
+                // Apply upforce and overcome gravity.
+                OMV.Vector3 correctionForce = upForce - PhysicsScene.DefaultGravity;
+                DetailLog("{0},BSPrim.PositionSanityCheck,applyForce,pos={1},upForce={2},correctionForce={3}", LocalID, _position, upForce, correctionForce);
+                AddForce(correctionForce, false, inTaintTime);
                 ret = true;
             }
         }
 
-        // The above code computes a force to apply to correct any out-of-bounds problems. Apply same.
-        // TODO: This should be intergrated with a geneal physics action mechanism.
-        // TODO: This should be moderated with PID'ness.
-        if (ret)
-        {
-            // Apply upforce and overcome gravity.
-            OMV.Vector3 correctionForce = upForce - PhysicsScene.DefaultGravity;
-            DetailLog("{0},BSPrim.PositionSanityCheck,applyForce,pos={1},upForce={2},correctionForce={3}", LocalID, _position, upForce, correctionForce);
-            AddForce(correctionForce, false, inTaintTime);
-        }
         return ret;
     }