BulletSim: check for completely degenerate meshes (ones with all

triangles having zero width) and output an error rather than
throwing and exception.

1 files changed, 19 insertions, 9 deletions

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSShapeCollection.cs b/OpenSim/Region/Physics/BulletSPlugin/BSShapeCollection.cs
index fe0f984..15747c9 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSShapeCollection.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSShapeCollection.cs
@@ -608,7 +608,7 @@ public sealed class BSShapeCollection : IDisposable
         // Since we're recreating new, get rid of the reference to the previous shape
         DereferenceShape(prim.PhysShape, shapeCallback);
 
-        newShape = CreatePhysicalMesh(prim.PhysObjectName, newMeshKey, prim.BaseShape, prim.Size, lod);
+        newShape = CreatePhysicalMesh(prim, newMeshKey, prim.BaseShape, prim.Size, lod);
         // Take evasive action if the mesh was not constructed.
         newShape = VerifyMeshCreated(newShape, prim);
 
@@ -619,7 +619,7 @@ public sealed class BSShapeCollection : IDisposable
         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)
+    private BulletShape CreatePhysicalMesh(BSPhysObject prim, System.UInt64 newMeshKey, PrimitiveBaseShape pbs, OMV.Vector3 size, float lod)
     {
         BulletShape newShape = new BulletShape();
 
@@ -631,7 +631,7 @@ public sealed class BSShapeCollection : IDisposable
         }
         else
         {
-            IMesh meshData = PhysicsScene.mesher.CreateMesh(objName, pbs, size, lod, 
+            IMesh meshData = PhysicsScene.mesher.CreateMesh(prim.PhysObjectName, pbs, size, lod, 
                                         false,  // say it is not physical so a bounding box is not built
                                         false   // do not cache the mesh and do not use previously built versions
                                         );
@@ -651,18 +651,20 @@ public sealed class BSShapeCollection : IDisposable
                     realIndicesIndex = 0;
                     for (int tri = 0; tri < indices.Length; tri += 3)
                     {
+                        // Compute displacements into vertex array for each vertex of the triangle
                         int v1 = indices[tri + 0] * 3;
                         int v2 = indices[tri + 1] * 3;
                         int v3 = indices[tri + 2] * 3;
-                        if (!((verticesAsFloats[v1 + 0] == verticesAsFloats[v2 + 0]
+                        // Check to see if any two of the vertices are the same
+                        if (!( (  verticesAsFloats[v1 + 0] == verticesAsFloats[v2 + 0]
                                && verticesAsFloats[v1 + 1] == verticesAsFloats[v2 + 1]
                                && verticesAsFloats[v1 + 2] == verticesAsFloats[v2 + 2])
-                            || (verticesAsFloats[v2 + 0] == verticesAsFloats[v3 + 0]
+                            || (  verticesAsFloats[v2 + 0] == verticesAsFloats[v3 + 0]
                                && verticesAsFloats[v2 + 1] == verticesAsFloats[v3 + 1]
                                && verticesAsFloats[v2 + 2] == verticesAsFloats[v3 + 2])
-                            || (verticesAsFloats[v1 + 0] == verticesAsFloats[v3 + 0]
+                            || (  verticesAsFloats[v1 + 0] == verticesAsFloats[v3 + 0]
                                && verticesAsFloats[v1 + 1] == verticesAsFloats[v3 + 1]
-                               && verticesAsFloats[v1 + 2] == verticesAsFloats[v3 + 2]))
+                               && verticesAsFloats[v1 + 2] == verticesAsFloats[v3 + 2]) )
                         )
                         {
                             // None of the vertices of the triangles are the same. This is a good triangle;
@@ -676,8 +678,16 @@ public sealed class BSShapeCollection : IDisposable
                 DetailLog("{0},BSShapeCollection.CreatePhysicalMesh,origTri={1},realTri={2},numVerts={3}",
                             BSScene.DetailLogZero, indices.Length / 3, realIndicesIndex / 3, verticesAsFloats.Length / 3);
 
-                newShape = PhysicsScene.PE.CreateMeshShape(PhysicsScene.World,
-                                    realIndicesIndex, indices, verticesAsFloats.Length/3, verticesAsFloats);
+                if (realIndicesIndex != 0)
+                {
+                    newShape = PhysicsScene.PE.CreateMeshShape(PhysicsScene.World,
+                                        realIndicesIndex, indices, verticesAsFloats.Length / 3, verticesAsFloats);
+                }
+                else
+                {
+                    PhysicsScene.Logger.ErrorFormat("{0} All mesh triangles degenerate. Prim {1} at {2} in {3}",
+                                        LogHeader, prim.PhysObjectName, prim.RawPosition, PhysicsScene.Name);
+                }
             }
         }
         newShape.shapeKey = newMeshKey;