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

@@ -640,13 +640,15 @@ public sealed class BSShapeCollection : IDisposable
             {
 
                 int[] indices = meshData.getIndexListAsInt();
-                // int realIndicesIndex = indices.Length;
+                int realIndicesIndex = indices.Length;
                 float[] verticesAsFloats = meshData.getVertexListAsFloat();
 
+                if (BSParam.ShouldRemoveZeroWidthTriangles)
+                {
                     // Remove degenerate triangles. These are triangles with two of the vertices
                     //    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;
+                    realIndicesIndex = 0;
                     for (int tri = 0; tri < indices.Length; tri += 3)
                     {
                         int v1 = indices[tri + 0] * 3;
@@ -670,6 +672,7 @@ public sealed class BSShapeCollection : IDisposable
                             realIndicesIndex += 3;
                         }
                     }
+                }
                 DetailLog("{0},BSShapeCollection.CreatePhysicalMesh,origTri={1},realTri={2},numVerts={3}",
                             BSScene.DetailLogZero, indices.Length / 3, realIndicesIndex / 3, verticesAsFloats.Length / 3);