7 files changed, 213 insertions, 20 deletions

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSAPIUnman.cs b/OpenSim/Region/Physics/BulletSPlugin/BSAPIUnman.cs
index 3a27d2c..77ea3ed 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSAPIUnman.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSAPIUnman.cs
@@ -286,7 +286,7 @@ public override void SetShapeCollisionMargin(BulletShape shape, float margin)
 {
     BulletShapeUnman shapeu = shape as BulletShapeUnman;
     if (shapeu != null && shapeu.HasPhysicalShape)
-        BSAPICPP.SetShapeCollisionMargin2(shapeu.ptr, margin);
+        BSAPICPP.SetShapeCollisionMargin(shapeu.ptr, margin);
 }
 
 public override BulletShape BuildCapsuleShape(BulletWorld world, float radius, float height, Vector3 scale)
@@ -1420,7 +1420,7 @@ public static extern IntPtr BuildNativeShape2(IntPtr world, ShapeData shapeData)
 public static extern bool IsNativeShape2(IntPtr shape);
 
 [DllImport("BulletSim", CallingConvention = CallingConvention.Cdecl), SuppressUnmanagedCodeSecurity]
-public static extern void SetShapeCollisionMargin2(IntPtr shape, float margin);
+public static extern void SetShapeCollisionMargin(IntPtr shape, float margin);
 
 [DllImport("BulletSim", CallingConvention = CallingConvention.Cdecl), SuppressUnmanagedCodeSecurity]
 public static extern IntPtr BuildCapsuleShape2(IntPtr world, float radius, float height, Vector3 scale);
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs b/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
index 38596fa..5549984 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
@@ -1201,8 +1201,9 @@ namespace OpenSim.Region.Physics.BulletSPlugin
 
             VehicleAddForce(appliedGravity);
 
-            VDetailLog("{0},  MoveLinear,applyGravity,vehGrav={1},collid={2},appliedForce={3}", 
-                            Prim.LocalID, m_VehicleGravity, Prim.IsColliding, appliedGravity);
+            VDetailLog("{0},  MoveLinear,applyGravity,vehGrav={1},collid={2},fudge={3},mass={4},appliedForce={3}", 
+                            Prim.LocalID, m_VehicleGravity,
+                            Prim.IsColliding, BSParam.VehicleGroundGravityFudge, m_vehicleMass, appliedGravity);
         }
 
         // =======================================================================
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs b/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs
index 77bdacb..4d89a88 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs
@@ -39,6 +39,20 @@ public static class BSParam
 {
     private static string LogHeader = "[BULLETSIM PARAMETERS]"; 
 
+    // Tuning notes:
+    // From: http://bulletphysics.org/Bullet/phpBB3/viewtopic.php?t=6575
+    //    Contact points can be added even if the distance is positive. The constraint solver can deal with
+    //    contacts with positive distances as well as negative (penetration). Contact points are discarded
+    //    if the distance exceeds a certain threshold.
+    //    Bullet has a contact processing threshold and a contact breaking threshold.
+    //    If the distance is larger than the contact breaking threshold, it will be removed after one frame.
+    //    If the distance is larger than the contact processing threshold, the constraint solver will ignore it.
+
+    //    This is separate/independent from the collision margin. The collision margin increases the object a bit
+    //    to improve collision detection performance and accuracy.
+    // ===================
+    // From: 
+
     // Level of Detail values kept as float because that's what the Meshmerizer wants
     public static float MeshLOD { get; private set; }
     public static float MeshCircularLOD { get; private set; }
@@ -74,9 +88,11 @@ public static class BSParam
     public static bool ShouldRemoveZeroWidthTriangles { get; private set; }
 
     public static float TerrainImplementation { get; private set; }
+    public static int TerrainMeshMagnification { get; private set; }
     public static float TerrainFriction { get; private set; }
     public static float TerrainHitFraction { get; private set; }
     public static float TerrainRestitution { get; private set; }
+    public static float TerrainContactProcessingThreshold { get; private set; }
     public static float TerrainCollisionMargin { get; private set; }
 
     public static float DefaultFriction { get; private set; }
@@ -446,6 +462,10 @@ public static class BSParam
             (float)BSTerrainPhys.TerrainImplementation.Mesh,
             (s) => { return TerrainImplementation; },
             (s,v) => { TerrainImplementation = v; } ),
+        new ParameterDefn<int>("TerrainMeshMagnification", "Number of times the 256x256 heightmap is multiplied to create the terrain mesh" ,
+            3,
+            (s) => { return TerrainMeshMagnification; },
+            (s,v) => { TerrainMeshMagnification = v; } ),
         new ParameterDefn<float>("TerrainFriction", "Factor to reduce movement against terrain surface" ,
             0.3f,
             (s) => { return TerrainFriction; },
@@ -458,6 +478,10 @@ public static class BSParam
             0f,
             (s) => { return TerrainRestitution; },
             (s,v) => { TerrainRestitution = v;  /* TODO: set on real terrain */ } ),
+        new ParameterDefn<float>("TerrainContactProcessingThreshold", "Distance from terrain to stop processing collisions" ,
+            0.0f,
+            (s) => { return TerrainContactProcessingThreshold; },
+            (s,v) => { TerrainContactProcessingThreshold = v;  /* TODO: set on real terrain */ } ),
         new ParameterDefn<float>("TerrainCollisionMargin", "Margin where collision checking starts" ,
             0.08f,
             (s) => { return TerrainCollisionMargin; },
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
index a465613..2cbbe9a 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
@@ -947,9 +947,9 @@ public class BSPrim : BSPhysObject
             ZeroMotion(true);
 
             // Set various physical properties so other object interact properly
-            MaterialAttributes matAttrib = BSMaterials.GetAttributes(Material, false);
             PhysicsScene.PE.SetFriction(PhysBody, Friction);
             PhysicsScene.PE.SetRestitution(PhysBody, Restitution);
+            PhysicsScene.PE.SetContactProcessingThreshold(PhysBody, BSParam.ContactProcessingThreshold);
 
             // Mass is zero which disables a bunch of physics stuff in Bullet
             UpdatePhysicalMassProperties(0f, false);
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSShapeCollection.cs b/OpenSim/Region/Physics/BulletSPlugin/BSShapeCollection.cs
index 2e54a93..05c147d 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSShapeCollection.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSShapeCollection.cs
@@ -687,7 +687,7 @@ public sealed class BSShapeCollection : IDisposable
                 }
                 else
                 {
-                    PhysicsScene.Logger.ErrorFormat("{0} All mesh triangles degenerate. Prim {1} at {2} in {3}",
+                    PhysicsScene.Logger.DebugFormat("{0} All mesh triangles degenerate. Prim {1} at {2} in {3}",
                                         LogHeader, prim.PhysObjectName, prim.RawPosition, PhysicsScene.Name);
                 }
             }
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSTerrainManager.cs b/OpenSim/Region/Physics/BulletSPlugin/BSTerrainManager.cs
index e8040d8..a60946d 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSTerrainManager.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSTerrainManager.cs
@@ -263,6 +263,7 @@ public sealed class BSTerrainManager : IDisposable
 
                 if (MegaRegionParentPhysicsScene == null)
                 {
+                    // This terrain is not part of the mega-region scheme. Create vanilla terrain.
                     BSTerrainPhys newTerrainPhys = BuildPhysicalTerrain(terrainRegionBase, id, heightMap, minCoords, maxCoords);
                     m_terrains.Add(terrainRegionBase, newTerrainPhys);
 
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSTerrainMesh.cs b/OpenSim/Region/Physics/BulletSPlugin/BSTerrainMesh.cs
index 57a5ff2..a9cd8a1 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSTerrainMesh.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSTerrainMesh.cs
@@ -76,11 +76,26 @@ public sealed class BSTerrainMesh : BSTerrainPhys
         m_sizeX = (int)(maxCoords.X - minCoords.X);
         m_sizeY = (int)(maxCoords.Y - minCoords.Y);
 
-        if (!BSTerrainMesh.ConvertHeightmapToMesh(PhysicsScene, initialMap,
-                            m_sizeX, m_sizeY,
-                            (float)m_sizeX, (float)m_sizeY,
-                            Vector3.Zero, 1.0f,
-                            out indicesCount, out indices, out verticesCount, out vertices))
+        bool meshCreationSuccess = false;
+        if (BSParam.TerrainMeshMagnification == 1)
+        {
+            // If a magnification of one, use the old routine that is tried and true.
+            meshCreationSuccess = BSTerrainMesh.ConvertHeightmapToMesh(PhysicsScene,
+                                            initialMap, m_sizeX, m_sizeY,       // input size
+                                            Vector3.Zero,                       // base for mesh
+                                            out indicesCount, out indices, out verticesCount, out vertices);
+        }
+        else
+        {
+            // Other magnifications use the newer routine
+            meshCreationSuccess = BSTerrainMesh.ConvertHeightmapToMesh2(PhysicsScene,
+                                            initialMap, m_sizeX, m_sizeY,       // input size
+                                            BSParam.TerrainMeshMagnification,
+                                            physicsScene.TerrainManager.DefaultRegionSize,
+                                            Vector3.Zero,                       // base for mesh
+                                            out indicesCount, out indices, out verticesCount, out vertices);
+        }
+        if (!meshCreationSuccess)
         {
             // DISASTER!!
             PhysicsScene.DetailLog("{0},BSTerrainMesh.create,failedConversionOfHeightmap", ID);
@@ -88,6 +103,7 @@ public sealed class BSTerrainMesh : BSTerrainPhys
             // Something is very messed up and a crash is in our future.
             return;
         }
+
         PhysicsScene.DetailLog("{0},BSTerrainMesh.create,meshed,indices={1},indSz={2},vertices={3},vertSz={4}", 
                                 ID, indicesCount, indices.Length, verticesCount, vertices.Length);
 
@@ -112,11 +128,13 @@ public sealed class BSTerrainMesh : BSTerrainPhys
             // Something is very messed up and a crash is in our future.
             return;
         }
+        physicsScene.PE.SetShapeCollisionMargin(m_terrainShape, BSParam.TerrainCollisionMargin);
 
         // Set current terrain attributes
         PhysicsScene.PE.SetFriction(m_terrainBody, BSParam.TerrainFriction);
         PhysicsScene.PE.SetHitFraction(m_terrainBody, BSParam.TerrainHitFraction);
         PhysicsScene.PE.SetRestitution(m_terrainBody, BSParam.TerrainRestitution);
+        PhysicsScene.PE.SetContactProcessingThreshold(m_terrainBody, BSParam.TerrainContactProcessingThreshold);
         PhysicsScene.PE.SetCollisionFlags(m_terrainBody, CollisionFlags.CF_STATIC_OBJECT);
 
         // Static objects are not very massive.
@@ -184,9 +202,7 @@ public sealed class BSTerrainMesh : BSTerrainPhys
     // Return 'true' if successfully created.
     public static bool ConvertHeightmapToMesh( BSScene physicsScene,
                                 float[] heightMap, int sizeX, int sizeY,    // parameters of incoming heightmap
-                                float extentX, float extentY,               // zero based range for output vertices
                                 Vector3 extentBase,                         // base to be added to all vertices
-                                float magnification,                        // number of vertices to create between heightMap coords
                                 out int indicesCountO, out int[] indicesO,
                                 out int verticesCountO, out float[] verticesO)
     {
@@ -207,17 +223,15 @@ public sealed class BSTerrainMesh : BSTerrainPhys
         //    of the heightmap.
         try
         {
-            // One vertice per heightmap value plus the vertices off the top and bottom edge.
+            // One vertice per heightmap value plus the vertices off the side and bottom edge.
             int totalVertices = (sizeX + 1) * (sizeY + 1);
             vertices = new float[totalVertices * 3];
             int totalIndices = sizeX * sizeY * 6;
             indices = new int[totalIndices];
 
-            float magX = (float)sizeX / extentX;
-            float magY = (float)sizeY / extentY;
             if (physicsScene != null)
-                physicsScene.DetailLog("{0},BSTerrainMesh.ConvertHeightMapToMesh,totVert={1},totInd={2},extentBase={3},magX={4},magY={5}",
-                                    BSScene.DetailLogZero, totalVertices, totalIndices, extentBase, magX, magY);
+                physicsScene.DetailLog("{0},BSTerrainMesh.ConvertHeightMapToMesh,totVert={1},totInd={2},extentBase={3}",
+                                    BSScene.DetailLogZero, totalVertices, totalIndices, extentBase);
             float minHeight = float.MaxValue;
             // Note that sizeX+1 vertices are created since there is land between this and the next region.
             for (int yy = 0; yy <= sizeY; yy++)
@@ -230,8 +244,8 @@ public sealed class BSTerrainMesh : BSTerrainPhys
                     if (xx == sizeX) offset -= 1;
                     float height = heightMap[offset];
                     minHeight = Math.Min(minHeight, height);
-                    vertices[verticesCount + 0] = (float)xx * magX + extentBase.X;
-                    vertices[verticesCount + 1] = (float)yy * magY + extentBase.Y;
+                    vertices[verticesCount + 0] = (float)xx + extentBase.X;
+                    vertices[verticesCount + 1] = (float)yy + extentBase.Y;
                     vertices[verticesCount + 2] = height + extentBase.Z;
                     verticesCount += 3;
                 }
@@ -270,5 +284,158 @@ public sealed class BSTerrainMesh : BSTerrainPhys
 
         return ret;
     }
+
+    private class HeightMapGetter
+    {
+        private float[] m_heightMap;
+        private int m_sizeX;
+        private int m_sizeY;
+        public HeightMapGetter(float[] pHeightMap, int pSizeX, int pSizeY)
+        {
+            m_heightMap = pHeightMap;
+            m_sizeX = pSizeX;
+            m_sizeY = pSizeY;
+        }
+        // The heightmap is extended as an infinite plane at the last height
+        public float GetHeight(int xx, int yy)
+        {
+            int offset = 0;
+            // Extend the height with the height from the last row or column
+            if (yy >= m_sizeY)
+                if (xx >= m_sizeX)
+                    offset = (m_sizeY - 1) * m_sizeX + (m_sizeX - 1);
+                else
+                    offset = (m_sizeY - 1) * m_sizeX + xx;
+            else
+                if (xx >= m_sizeX)
+                    offset = yy * m_sizeX + (m_sizeX - 1);
+                else
+                    offset = yy * m_sizeX + xx;
+
+            return m_heightMap[offset];
+        }
+    }
+
+    // Convert the passed heightmap to mesh information suitable for CreateMeshShape2().
+    // Version that handles magnification.
+    // Return 'true' if successfully created.
+    public static bool ConvertHeightmapToMesh2( BSScene physicsScene,
+                                float[] heightMap, int sizeX, int sizeY,    // parameters of incoming heightmap
+                                int magnification,                          // number of vertices per heighmap step
+                                Vector3 extent,                             // dimensions of the output mesh
+                                Vector3 extentBase,                         // base to be added to all vertices
+                                out int indicesCountO, out int[] indicesO,
+                                out int verticesCountO, out float[] verticesO)
+    {
+        bool ret = false;
+
+        int indicesCount = 0;
+        int verticesCount = 0;
+        int[] indices = new int[0];
+        float[] vertices = new float[0];
+
+        HeightMapGetter hmap = new HeightMapGetter(heightMap, sizeX, sizeY);
+
+        // The vertices dimension of the output mesh
+        int meshX = sizeX * magnification;
+        int meshY = sizeY * magnification;
+        // The output size of one mesh step
+        float meshXStep = extent.X / meshX;
+        float meshYStep = extent.Y / meshY;
+
+        // Create an array of vertices that is meshX+1 by meshY+1 (note the loop
+        //    from zero to <= meshX). The triangle indices are then generated as two triangles
+        //    per heightmap point. There are meshX by meshY of these squares. The extra row and
+        //    column of vertices are used to complete the triangles of the last row and column
+        //    of the heightmap.
+        try
+        {
+            // Vertices for the output heightmap plus one on the side and bottom to complete triangles
+            int totalVertices = (meshX + 1) * (meshY + 1);
+            vertices = new float[totalVertices * 3];
+            int totalIndices = meshX * meshY * 6;
+            indices = new int[totalIndices];
+
+            if (physicsScene != null)
+                physicsScene.DetailLog("{0},BSTerrainMesh.ConvertHeightMapToMesh2,inSize={1},outSize={2},totVert={3},totInd={4},extentBase={5}",
+                                    BSScene.DetailLogZero, new Vector2(sizeX, sizeY), new Vector2(meshX, meshY),
+                                    totalVertices, totalIndices, extentBase);
+
+            float minHeight = float.MaxValue;
+            // Note that sizeX+1 vertices are created since there is land between this and the next region.
+            // Loop through the output vertices and compute the mediun height in between the input vertices
+            for (int yy = 0; yy <= meshY; yy++)
+            {
+                for (int xx = 0; xx <= meshX; xx++)     // Hint: the "<=" means we go around sizeX + 1 times
+                {
+                    float offsetY = (float)yy * (float)sizeY / (float)meshY;     // The Y that is closest to the mesh point
+                    int stepY = (int)offsetY;
+                    float fractionalY = offsetY - (float)stepY;
+                    float offsetX = (float)xx * (float)sizeX / (float)meshX;     // The X that is closest to the mesh point
+                    int stepX = (int)offsetX;
+                    float fractionalX = offsetX - (float)stepX;
+
+                    // physicsScene.DetailLog("{0},BSTerrainMesh.ConvertHeightMapToMesh2,xx={1},yy={2},offX={3},stepX={4},fractX={5},offY={6},stepY={7},fractY={8}",
+                    //                 BSScene.DetailLogZero, xx, yy, offsetX, stepX, fractionalX, offsetY, stepY, fractionalY);
+
+                    // get the four corners of the heightmap square the mesh point is in
+                    float heightUL = hmap.GetHeight(stepX    , stepY    );
+                    float heightUR = hmap.GetHeight(stepX + 1, stepY    );
+                    float heightLL = hmap.GetHeight(stepX    , stepY + 1);
+                    float heightLR = hmap.GetHeight(stepX + 1, stepY + 1);
+
+                    // bilinear interplolation
+                    float height = heightUL * (1 - fractionalX) * (1 - fractionalY)
+                                 + heightUR * fractionalX       * (1 - fractionalY)
+                                 + heightLL * (1 - fractionalX) * fractionalY
+                                 + heightLR * fractionalX       * fractionalY;
+
+                    // physicsScene.DetailLog("{0},BSTerrainMesh.ConvertHeightMapToMesh2,heightUL={1},heightUR={2},heightLL={3},heightLR={4},heightMap={5}",
+                    //                 BSScene.DetailLogZero, heightUL, heightUR, heightLL, heightLR, height);
+
+                    minHeight = Math.Min(minHeight, height);
+
+                    vertices[verticesCount + 0] = (float)xx * meshXStep + extentBase.X;
+                    vertices[verticesCount + 1] = (float)yy * meshYStep + extentBase.Y;
+                    vertices[verticesCount + 2] = height + extentBase.Z;
+                    verticesCount += 3;
+                }
+            }
+            // The number of vertices generated
+            verticesCount /= 3;
+
+            // Loop through all the heightmap squares and create indices for the two triangles for that square
+            for (int yy = 0; yy < meshY; yy++)
+            {
+                for (int xx = 0; xx < meshX; xx++)
+                {
+                    int offset = yy * (meshX + 1) + xx;
+                    // Each vertices is presumed to be the upper left corner of a box of two triangles
+                    indices[indicesCount + 0] = offset;
+                    indices[indicesCount + 1] = offset + 1;
+                    indices[indicesCount + 2] = offset + meshX + 1; // accounting for the extra column
+                    indices[indicesCount + 3] = offset + 1;
+                    indices[indicesCount + 4] = offset + meshX + 2;
+                    indices[indicesCount + 5] = offset + meshX + 1;
+                    indicesCount += 6;
+                }
+            }
+
+            ret = true;
+        }
+        catch (Exception e)
+        {
+            if (physicsScene != null)
+                physicsScene.Logger.ErrorFormat("{0} Failed conversion of heightmap to mesh. For={1}/{2}, e={3}",
+                                                LogHeader, physicsScene.RegionName, extentBase, e);
+        }
+
+        indicesCountO = indicesCount;
+        indicesO = indices;
+        verticesCountO = verticesCount;
+        verticesO = vertices;
+
+        return ret;
+    }
 }
 }