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diff --git a/OpenSim/Region/PhysicsModules/ConvexDecompositionDotNet/Concavity.cs b/OpenSim/Region/PhysicsModules/ConvexDecompositionDotNet/Concavity.cs
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+/* The MIT License
+ * 
+ * Copyright (c) 2010 Intel Corporation.
+ * All rights reserved.
+ *
+ * Based on the convexdecomposition library from 
+ * <http://codesuppository.googlecode.com> by John W. Ratcliff and Stan Melax.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace OpenSim.Region.Physics.ConvexDecompositionDotNet
+{
+    public static class Concavity
+    {
+        // compute's how 'concave' this object is and returns the total volume of the
+        // convex hull as well as the volume of the 'concavity' which was found.
+        public static float computeConcavity(List<float3> vertices, List<int> indices, ref float4 plane, ref float volume)
+        {
+            float cret = 0f;
+            volume = 1f;
+
+            HullResult result = new HullResult();
+            HullDesc desc = new HullDesc();
+
+            desc.MaxFaces = 256;
+            desc.MaxVertices = 256;
+            desc.SetHullFlag(HullFlag.QF_TRIANGLES);
+            desc.Vertices = vertices;
+
+            HullError ret = HullUtils.CreateConvexHull(desc, ref result);
+
+            if (ret == HullError.QE_OK)
+            {
+                volume = computeMeshVolume2(result.OutputVertices, result.Indices);
+
+                // ok..now..for each triangle on the original mesh..
+                // we extrude the points to the nearest point on the hull.
+                List<CTri> tris = new List<CTri>();
+
+                for (int i = 0; i < result.Indices.Count / 3; i++)
+                {
+                    int i1 = result.Indices[i * 3 + 0];
+                    int i2 = result.Indices[i * 3 + 1];
+                    int i3 = result.Indices[i * 3 + 2];
+
+                    float3 p1 = result.OutputVertices[i1];
+                    float3 p2 = result.OutputVertices[i2];
+                    float3 p3 = result.OutputVertices[i3];
+
+                    CTri t = new CTri(p1, p2, p3, i1, i2, i3);
+                    tris.Add(t);
+                }
+
+                // we have not pre-computed the plane equation for each triangle in the convex hull..
+                float totalVolume = 0;
+
+                List<CTri> ftris = new List<CTri>(); // 'feature' triangles.
+                List<CTri> input_mesh = new List<CTri>();
+
+                for (int i = 0; i < indices.Count / 3; i++)
+                {
+                    int i1 = indices[i * 3 + 0];
+                    int i2 = indices[i * 3 + 1];
+                    int i3 = indices[i * 3 + 2];
+
+                    float3 p1 = vertices[i1];
+                    float3 p2 = vertices[i2];
+                    float3 p3 = vertices[i3];
+
+                    CTri t = new CTri(p1, p2, p3, i1, i2, i3);
+                    input_mesh.Add(t);
+                }
+
+                for (int i = 0; i < indices.Count / 3; i++)
+                {
+                    int i1 = indices[i * 3 + 0];
+                    int i2 = indices[i * 3 + 1];
+                    int i3 = indices[i * 3 + 2];
+
+                    float3 p1 = vertices[i1];
+                    float3 p2 = vertices[i2];
+                    float3 p3 = vertices[i3];
+
+                    CTri t = new CTri(p1, p2, p3, i1, i2, i3);
+
+                    featureMatch(t, tris, input_mesh);
+
+                    if (t.mConcavity > 0.05f)
+                    {
+                        float v = t.getVolume();
+                        totalVolume += v;
+                        ftris.Add(t);
+                    }
+                }
+
+                SplitPlane.computeSplitPlane(vertices, indices, ref plane);
+                cret = totalVolume;
+            }
+
+            return cret;
+        }
+
+        public static bool featureMatch(CTri m, List<CTri> tris, List<CTri> input_mesh)
+        {
+            bool ret = false;
+            float neardot = 0.707f;
+            m.mConcavity = 0;
+
+            for (int i = 0; i < tris.Count; i++)
+            {
+                CTri t = tris[i];
+
+                if (t.samePlane(m))
+                {
+                    ret = false;
+                    break;
+                }
+
+                float dot = float3.dot(t.mNormal, m.mNormal);
+
+                if (dot > neardot)
+                {
+                    float d1 = t.planeDistance(m.mP1);
+                    float d2 = t.planeDistance(m.mP2);
+                    float d3 = t.planeDistance(m.mP3);
+
+                    if (d1 > 0.001f || d2 > 0.001f || d3 > 0.001f) // can't be near coplaner!
+                    {
+                        neardot = dot;
+
+                        t.raySect(m.mP1, m.mNormal, ref m.mNear1);
+                        t.raySect(m.mP2, m.mNormal, ref m.mNear2);
+                        t.raySect(m.mP3, m.mNormal, ref m.mNear3);
+
+                        ret = true;
+                    }
+                }
+            }
+
+            if (ret)
+            {
+                m.mC1 = m.mP1.Distance(m.mNear1);
+                m.mC2 = m.mP2.Distance(m.mNear2);
+                m.mC3 = m.mP3.Distance(m.mNear3);
+
+                m.mConcavity = m.mC1;
+
+                if (m.mC2 > m.mConcavity)
+                    m.mConcavity = m.mC2;
+                if (m.mC3 > m.mConcavity)
+                    m.mConcavity = m.mC3;
+            }
+
+            return ret;
+        }
+
+        private static float det(float3 p1, float3 p2, float3 p3)
+        {
+            return p1.x * p2.y * p3.z + p2.x * p3.y * p1.z + p3.x * p1.y * p2.z - p1.x * p3.y * p2.z - p2.x * p1.y * p3.z - p3.x * p2.y * p1.z;
+        }
+
+        public static float computeMeshVolume(List<float3> vertices, List<int> indices)
+        {
+            float volume = 0f;
+
+            for (int i = 0; i < indices.Count / 3; i++)
+            {
+                float3 p1 = vertices[indices[i * 3 + 0]];
+                float3 p2 = vertices[indices[i * 3 + 1]];
+                float3 p3 = vertices[indices[i * 3 + 2]];
+
+                volume += det(p1, p2, p3); // compute the volume of the tetrahedran relative to the origin.
+            }
+
+            volume *= (1.0f / 6.0f);
+            if (volume < 0f)
+                return -volume;
+            return volume;
+        }
+
+        public static float computeMeshVolume2(List<float3> vertices, List<int> indices)
+        {
+            float volume = 0f;
+
+            float3 p0 = vertices[0];
+            for (int i = 0; i < indices.Count / 3; i++)
+            {
+                float3 p1 = vertices[indices[i * 3 + 0]];
+                float3 p2 = vertices[indices[i * 3 + 1]];
+                float3 p3 = vertices[indices[i * 3 + 2]];
+
+                volume += tetVolume(p0, p1, p2, p3); // compute the volume of the tetrahedron relative to the root vertice
+            }
+
+            return volume * (1.0f / 6.0f);
+        }
+
+        private static float tetVolume(float3 p0, float3 p1, float3 p2, float3 p3)
+        {
+            float3 a = p1 - p0;
+            float3 b = p2 - p0;
+            float3 c = p3 - p0;
+
+            float3 cross = float3.cross(b, c);
+            float volume = float3.dot(a, cross);
+
+            if (volume < 0f)
+                return -volume;
+            return volume;
+        }
+    }
+}