fixed btSoftBodyConcaveCollisionAlgorithm, wrong bounding box transformation

added vertex welding option for btTriangleMesh (brute-force slow)
reject appendFace for some degenerate triangles (all 3 vertices/nodes need to be different)
add setVelocity method for btSoftBody

src/BulletCollision/CollisionShapes/btTriangleMesh.cpp

@@ -19,7 +19,8 @@ subject to the following restrictions:
 
 btTriangleMesh::btTriangleMesh (bool use32bitIndices,bool use4componentVertices)
 :m_use32bitIndices(use32bitIndices),
-m_use4componentVertices(use4componentVertices)
+m_use4componentVertices(use4componentVertices),
+m_weldingThreshold(0.0)
 {
 	btIndexedMesh meshIndex;
 	meshIndex.m_numTriangles = 0;
@@ -60,49 +61,66 @@ m_use4componentVertices(use4componentVertices)
 
 }
 
+void	btTriangleMesh::addIndex(int index)
+{
+	if (m_use32bitIndices)
+	{
+		m_32bitIndices.push_back(index);
+		m_indexedMeshes[0].m_triangleIndexBase = (unsigned char*) &m_32bitIndices[0];
+	} else
+	{
+		m_16bitIndices.push_back(index);
+		m_indexedMeshes[0].m_triangleIndexBase = (unsigned char*) &m_16bitIndices[0];
+	}
+}
+
+int	btTriangleMesh::findOrAddVertex(const btVector3& vertex)
+{
+	//return index of new/existing vertex
+	//todo: could use acceleration structure for this
+	if (m_use4componentVertices)
+	{
+		for (int i=0;i< m_4componentVertices.size();i++)
+		{
+			if ((m_4componentVertices[i]-vertex).length2() <= m_weldingThreshold)
+			{
+				return i;
+			}
+		}
+		m_indexedMeshes[0].m_numVertices++;
+		m_4componentVertices.push_back(vertex);
+		m_indexedMeshes[0].m_vertexBase = (unsigned char*)&m_4componentVertices[0];
+
+		return m_4componentVertices.size()-1;
+		
+	} else
+	{
+		
+		for (int i=0;i< m_3componentVertices.size();i+=3)
+		{
+			btVector3 vtx(m_3componentVertices[i],m_3componentVertices[i+1],m_3componentVertices[i+2]);
+			if ((vtx-vertex).length2() <= m_weldingThreshold)
+			{
+				return i/3;
+			}
+		}
+		m_3componentVertices.push_back(vertex.getX());
+		m_3componentVertices.push_back(vertex.getY());
+		m_3componentVertices.push_back(vertex.getZ());
+		m_indexedMeshes[0].m_numVertices++;
+		m_indexedMeshes[0].m_vertexBase = (unsigned char*)&m_3componentVertices[0];
+		return (m_3componentVertices.size()/3)-1;
+	}
+
+}
 		
 void	btTriangleMesh::addTriangle(const btVector3& vertex0,const btVector3& vertex1,const btVector3& vertex2)
 {
 	m_indexedMeshes[0].m_numTriangles++;
-	m_indexedMeshes[0].m_numVertices+=3;
+		
-
+	addIndex(findOrAddVertex(vertex0));
-	if (m_use4componentVertices)
+	addIndex(findOrAddVertex(vertex1));
-	{
+	addIndex(findOrAddVertex(vertex2));
-		m_4componentVertices.push_back(vertex0);
-		m_4componentVertices.push_back(vertex1);
-		m_4componentVertices.push_back(vertex2);
-		m_indexedMeshes[0].m_vertexBase = (unsigned char*)&m_4componentVertices[0];
-	} else
-	{
-		m_3componentVertices.push_back(vertex0.getX());
-		m_3componentVertices.push_back(vertex0.getY());
-		m_3componentVertices.push_back(vertex0.getZ());
-
-		m_3componentVertices.push_back(vertex1.getX());
-		m_3componentVertices.push_back(vertex1.getY());
-		m_3componentVertices.push_back(vertex1.getZ());
-
-		m_3componentVertices.push_back(vertex2.getX());
-		m_3componentVertices.push_back(vertex2.getY());
-		m_3componentVertices.push_back(vertex2.getZ());
-		m_indexedMeshes[0].m_vertexBase = (unsigned char*)&m_3componentVertices[0];
-	}
-
-	if (m_use32bitIndices)
-	{
-		int curIndex = m_32bitIndices.size();
-		m_32bitIndices.push_back(curIndex++);
-		m_32bitIndices.push_back(curIndex++);
-		m_32bitIndices.push_back(curIndex++);
-		m_indexedMeshes[0].m_triangleIndexBase = (unsigned char*) &m_32bitIndices[0];
-	} else
-	{
-		short curIndex = static_cast<short>(m_16bitIndices.size());
-		m_16bitIndices.push_back(curIndex++);
-		m_16bitIndices.push_back(curIndex++);
-		m_16bitIndices.push_back(curIndex++);
-		m_indexedMeshes[0].m_triangleIndexBase = (unsigned char*) &m_16bitIndices[0];
-	}
 }
 
 int btTriangleMesh::getNumTriangles() const

src/BulletCollision/CollisionShapes/btTriangleMesh.h

@@ -25,6 +25,7 @@ subject to the following restrictions:
 ///It allows either 32bit or 16bit indices, and 4 (x-y-z-w) or 3 (x-y-z) component vertices.
 ///If you want to share triangle/index data between graphics mesh and collision mesh (btBvhTriangleMeshShape), you can directly use btTriangleIndexVertexArray or derive your own class from btStridingMeshInterface.
 ///Performance of btTriangleMesh and btTriangleIndexVertexArray used in a btBvhTriangleMeshShape is the same.
+///It has a brute-force option to weld together closeby vertices.
 class btTriangleMesh : public btTriangleIndexVertexArray
 {
 	btAlignedObjectArray<btVector3>	m_4componentVertices;
@@ -34,11 +35,16 @@ class btTriangleMesh : public btTriangleIndexVertexArray
 	btAlignedObjectArray<unsigned short int>		m_16bitIndices;
 	bool	m_use32bitIndices;
 	bool	m_use4componentVertices;
-
+	
 
 	public:
+		btScalar	m_weldingThreshold;
+
 		btTriangleMesh (bool use32bitIndices=true,bool use4componentVertices=true);
 
+		int		findOrAddVertex(const btVector3& vertex);
+		void	addIndex(int index);
+
 		bool	getUse32bitIndices() const
 		{
 			return m_use32bitIndices;

src/BulletSoftBody/btSoftBody.cpp

@@ -284,6 +284,13 @@ m_faces.push_back(f);
 //
 void			btSoftBody::appendFace(int node0,int node1,int node2,Material* mat)
 {
+	if (node0==node1)
+		return;
+	if (node1==node2)
+		return;
+	if (node2==node0)
+		return;
+
 	appendFace(-1,mat);
 	Face&	f=m_faces[m_faces.size()-1];
 	btAssert(node0!=node1);
@@ -384,6 +391,20 @@ void			btSoftBody::addVelocity(const btVector3& velocity)
 	for(int i=0,ni=m_nodes.size();i<ni;++i) addVelocity(velocity,i);
 }
 
+/* Set velocity for the entire body										*/ 
+void				btSoftBody::setVelocity(	const btVector3& velocity)
+{
+	for(int i=0,ni=m_nodes.size();i<ni;++i) 
+	{
+		Node&	n=m_nodes[i];
+		if(n.m_im>0)
+		{
+			n.m_v	=	velocity;
+		}
+	}
+}
+
+
 //
 void			btSoftBody::addVelocity(const btVector3& velocity,int node)
 {

src/BulletSoftBody/btSoftBody.h

@@ -677,6 +677,10 @@ public:
 										int node);
 	/* Add velocity to the entire body										*/ 
 	void				addVelocity(	const btVector3& velocity);
+
+	/* Set velocity for the entire body										*/ 
+	void				setVelocity(	const btVector3& velocity);
+
 	/* Add velocity to a node of the body									*/ 
 	void				addVelocity(	const btVector3& velocity,
 										int node);

src/BulletSoftBody/btSoftBodyConcaveCollisionAlgorithm.cpp

@@ -32,7 +32,7 @@ subject to the following restrictions:
 #include "BulletCollision/NarrowPhaseCollision/btSubSimplexConvexCast.h"
 #include "BulletSoftBody/btSoftBody.h"
 
-#define BT_SOFTBODY_TRIANGLE_EXTRUSION btScalar(0.3)
+#define BT_SOFTBODY_TRIANGLE_EXTRUSION btScalar(0.06)//make this configurable
 
 btSoftBodyConcaveCollisionAlgorithm::btSoftBodyConcaveCollisionAlgorithm( const btCollisionAlgorithmConstructionInfo& ci, btCollisionObject* body0,btCollisionObject* body1,bool isSwapped)
 : btCollisionAlgorithm(ci),
@@ -210,44 +210,22 @@ btCollisionObject* ob = static_cast<btCollisionObject*>(m_triBody);
 void	btSoftBodyTriangleCallback::setTimeStepAndCounters(btScalar collisionMarginTriangle,const btDispatcherInfo& dispatchInfo,btManifoldResult* resultOut)
 {
 	m_dispatchInfoPtr = &dispatchInfo;
-	m_collisionMarginTriangle = collisionMarginTriangle;
+	m_collisionMarginTriangle = collisionMarginTriangle+btScalar(BT_SOFTBODY_TRIANGLE_EXTRUSION);
 	m_resultOut = resultOut;
 
-	//recalc aabbs
+	
-//	btTransform softbodyInTriangleSpace;
-//	softbodyInTriangleSpace = m_triBody->getWorldTransform().inverse() * m_softBody->getWorldTransform();
-//	btCollisionShape* convexShape = static_cast<btCollisionShape*>(m_convexBody->getCollisionShape());
-	//CollisionShape* triangleShape = static_cast<btCollisionShape*>(triBody->m_collisionShape);
 	btVector3	aabbWorldSpaceMin,aabbWorldSpaceMax;
 	m_softBody->getAabb(aabbWorldSpaceMin,aabbWorldSpaceMax);
-
 	btVector3 halfExtents = (aabbWorldSpaceMax-aabbWorldSpaceMin)*btScalar(0.5);
 	btVector3 softBodyCenter = (aabbWorldSpaceMax+aabbWorldSpaceMin)*btScalar(0.5);
 
-	btTransform	triInverse = m_triBody->getWorldTransform().inverse();
+	btTransform softTransform;
-
+	softTransform.setIdentity();
-	btMatrix3x3 abs_b = triInverse.getBasis().absolute();  
+	softTransform.setOrigin(softBodyCenter);
-	btPoint3 center = softBodyCenter + triInverse.getOrigin();
-
-	btVector3 extent = btVector3(abs_b[0].dot(halfExtents),
-		   abs_b[1].dot(halfExtents),
-		  abs_b[2].dot(halfExtents));
-//	extent += btVector3(getMargin(),getMargin(),getMargin());
-
-	m_aabbMin = center - extent;
-	m_aabbMax = center + extent;
-
-	btScalar extraMargin = collisionMarginTriangle+btScalar(BT_SOFTBODY_TRIANGLE_EXTRUSION);
-	btVector3 extra(extraMargin,extraMargin,extraMargin);
-
-	m_aabbMax += extra;
-	m_aabbMin -= extra;
-
-/*	btVector3 extra(2,2,2);
-	m_aabbMin = aabbWorldSpaceMin-extra;
-	m_aabbMax = aabbWorldSpaceMax+extra;
-*/
 
+	btTransform convexInTriangleSpace;
+	convexInTriangleSpace = m_triBody->getWorldTransform().inverse() * softTransform;
+	btTransformAabb(halfExtents,m_collisionMarginTriangle,convexInTriangleSpace,m_aabbMin,m_aabbMax);
 }
 
 void btSoftBodyConcaveCollisionAlgorithm::clearCache()