BulletSim: make removing zero width triangles from meshes optional

and, for the moment, default to 'off'.

OpenSim/Region/Physics/BulletSPlugin/BSParam.cs

@@ -62,6 +62,7 @@ public static class BSParam
     public static bool ShouldMeshSculptedPrim { get; private set; }   // cause scuplted prims to get meshed
     public static bool ShouldForceSimplePrimMeshing { get; private set; }   // if a cube or sphere, let Bullet do internal shapes
     public static bool ShouldUseHullsForPhysicalObjects { get; private set; }   // 'true' if should create hulls for physical objects
+    public static bool ShouldRemoveZeroWidthTriangles { get; private set; }
 
     public static float TerrainImplementation { get; private set; }
     public static float TerrainFriction { get; private set; }
@@ -218,6 +219,11 @@ public static class BSParam
             (s,cf,p,v) => { ShouldUseHullsForPhysicalObjects = cf.GetBoolean(p, BSParam.BoolNumeric(v)); },
             (s) => { return BSParam.NumericBool(ShouldUseHullsForPhysicalObjects); },
             (s,p,l,v) => { ShouldUseHullsForPhysicalObjects = BSParam.BoolNumeric(v); } ),
+        new ParameterDefn("ShouldRemoveZeroWidthTriangles", "If true, remove degenerate triangles from meshes",
+            ConfigurationParameters.numericFalse,
+            (s,cf,p,v) => { ShouldRemoveZeroWidthTriangles = cf.GetBoolean(p, BSParam.BoolNumeric(v)); },
+            (s) => { return BSParam.NumericBool(ShouldRemoveZeroWidthTriangles); },
+            (s,p,l,v) => { ShouldRemoveZeroWidthTriangles = BSParam.BoolNumeric(v); } ),
 
         new ParameterDefn("MeshLevelOfDetail", "Level of detail to render meshes (32, 16, 8 or 4. 32=most detailed)",
             32f,

OpenSim/Region/Physics/BulletSPlugin/BSShapeCollection.cs

@@ -640,34 +640,37 @@ public sealed class BSShapeCollection : IDisposable
             {
 
                 int[] indices = meshData.getIndexListAsInt();
-                // int realIndicesIndex = indices.Length;
+                int realIndicesIndex = indices.Length;
                 float[] verticesAsFloats = meshData.getVertexListAsFloat();
 
-                // Remove degenerate triangles. These are triangles with two of the vertices
+                if (BSParam.ShouldRemoveZeroWidthTriangles)
-                //    are the same. This is complicated by the problem that vertices are not
-                //    made unique in sculpties so we have to compare the values in the vertex.
-                int realIndicesIndex = 0;
-                for (int tri = 0; tri < indices.Length; tri += 3)
                 {
-                    int v1 = indices[tri + 0] * 3;
+                    // Remove degenerate triangles. These are triangles with two of the vertices
-                    int v2 = indices[tri + 1] * 3;
+                    //    are the same. This is complicated by the problem that vertices are not
-                    int v3 = indices[tri + 2] * 3;
+                    //    made unique in sculpties so we have to compare the values in the vertex.
-                    if (!( (  verticesAsFloats[v1 + 0] == verticesAsFloats[v2 + 0]
+                    realIndicesIndex = 0;
-                           && verticesAsFloats[v1 + 1] == verticesAsFloats[v2 + 1]
+                    for (int tri = 0; tri < indices.Length; tri += 3)
-                           && verticesAsFloats[v1 + 2] == verticesAsFloats[v2 + 2] )
-                        || (  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 + 1] == verticesAsFloats[v3 + 1]
-                           && verticesAsFloats[v1 + 2] == verticesAsFloats[v3 + 2] ) )
-                    )
                     {
-                        // None of the vertices of the triangles are the same. This is a good triangle;
+                        int v1 = indices[tri + 0] * 3;
-                        indices[realIndicesIndex + 0] = indices[tri + 0];
+                        int v2 = indices[tri + 1] * 3;
-                        indices[realIndicesIndex + 1] = indices[tri + 1];
+                        int v3 = indices[tri + 2] * 3;
-                        indices[realIndicesIndex + 2] = indices[tri + 2];
+                        if (!((verticesAsFloats[v1 + 0] == verticesAsFloats[v2 + 0]
-                        realIndicesIndex += 3;
+                               && verticesAsFloats[v1 + 1] == verticesAsFloats[v2 + 1]
+                               && verticesAsFloats[v1 + 2] == verticesAsFloats[v2 + 2])
+                            || (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 + 1] == verticesAsFloats[v3 + 1]
+                               && verticesAsFloats[v1 + 2] == verticesAsFloats[v3 + 2]))
+                        )
+                        {
+                            // None of the vertices of the triangles are the same. This is a good triangle;
+                            indices[realIndicesIndex + 0] = indices[tri + 0];
+                            indices[realIndicesIndex + 1] = indices[tri + 1];
+                            indices[realIndicesIndex + 2] = indices[tri + 2];
+                            realIndicesIndex += 3;
+                        }
                     }
                 }
                 DetailLog("{0},BSShapeCollection.CreatePhysicalMesh,origTri={1},realTri={2},numVerts={3}",