#include "CollisionShape2TriangleMesh.h" #include "btBulletCollisionCommon.h" #include "BulletCollision/CollisionShapes/btShapeHull.h"//to create a tesselation of a generic btConvexShape void CollisionShape2TriangleMesh(btCollisionShape* collisionShape, const btTransform& parentTransform, btAlignedObjectArray& vertexPositions, btAlignedObjectArray& vertexNormals, btAlignedObjectArray& indicesOut) { //todo: support all collision shape types switch (collisionShape->getShapeType()) { case SOFTBODY_SHAPE_PROXYTYPE: { //skip the soft body collision shape for now break; } case STATIC_PLANE_PROXYTYPE: { //draw a box, oriented along the plane normal const btStaticPlaneShape* staticPlaneShape = static_cast(collisionShape); btScalar planeConst = staticPlaneShape->getPlaneConstant(); const btVector3& planeNormal = staticPlaneShape->getPlaneNormal(); btVector3 planeOrigin = planeNormal * planeConst; btVector3 vec0,vec1; btPlaneSpace1(planeNormal,vec0,vec1); btScalar vecLen = 100.f; btVector3 verts[4]; verts[0] = planeOrigin + vec0*vecLen + vec1*vecLen; verts[1] = planeOrigin - vec0*vecLen + vec1*vecLen; verts[2] = planeOrigin - vec0*vecLen - vec1*vecLen; verts[3] = planeOrigin + vec0*vecLen - vec1*vecLen; int startIndex = vertexPositions.size(); indicesOut.push_back(startIndex+0); indicesOut.push_back(startIndex+1); indicesOut.push_back(startIndex+2); indicesOut.push_back(startIndex+0); indicesOut.push_back(startIndex+2); indicesOut.push_back(startIndex+3); btVector3 triNormal = parentTransform.getBasis()*planeNormal; for (int i=0;i<4;i++) { btVector3 vtxPos; btVector3 pos =parentTransform*verts[i]; vertexPositions.push_back(pos); vertexNormals.push_back(triNormal); } break; } case TRIANGLE_MESH_SHAPE_PROXYTYPE: { btBvhTriangleMeshShape* trimesh = (btBvhTriangleMeshShape*) collisionShape; btVector3 trimeshScaling = trimesh->getLocalScaling(); btStridingMeshInterface* meshInterface = trimesh->getMeshInterface(); btAlignedObjectArray vertices; btAlignedObjectArray indices; for (int partId=0;partIdgetNumSubParts();partId++) { const unsigned char *vertexbase = 0; int numverts = 0; PHY_ScalarType type = PHY_INTEGER; int stride = 0; const unsigned char *indexbase = 0; int indexstride = 0; int numfaces = 0; PHY_ScalarType indicestype = PHY_INTEGER; //PHY_ScalarType indexType=0; btVector3 triangleVerts[3]; meshInterface->getLockedReadOnlyVertexIndexBase(&vertexbase,numverts, type,stride,&indexbase,indexstride,numfaces,indicestype,partId); btVector3 aabbMin,aabbMax; for (int triangleIndex = 0 ; triangleIndex < numfaces;triangleIndex++) { unsigned int* gfxbase = (unsigned int*)(indexbase+triangleIndex*indexstride); for (int j=2;j>=0;j--) { int graphicsindex = indicestype==PHY_SHORT?((unsigned short*)gfxbase)[j]:gfxbase[j]; if (type == PHY_FLOAT) { float* graphicsbase = (float*)(vertexbase+graphicsindex*stride); triangleVerts[j] = btVector3( graphicsbase[0]*trimeshScaling.getX(), graphicsbase[1]*trimeshScaling.getY(), graphicsbase[2]*trimeshScaling.getZ()); } else { double* graphicsbase = (double*)(vertexbase+graphicsindex*stride); triangleVerts[j] = btVector3( btScalar(graphicsbase[0]*trimeshScaling.getX()), btScalar(graphicsbase[1]*trimeshScaling.getY()), btScalar(graphicsbase[2]*trimeshScaling.getZ())); } } indices.push_back(vertices.size()); vertices.push_back(triangleVerts[0]); indices.push_back(vertices.size()); vertices.push_back(triangleVerts[1]); indices.push_back(vertices.size()); vertices.push_back(triangleVerts[2]); btVector3 triNormal = (triangleVerts[1]-triangleVerts[0]).cross(triangleVerts[2]-triangleVerts[0]); btScalar dot = triNormal.dot(triNormal); //cull degenerate triangles if (dot >= SIMD_EPSILON*SIMD_EPSILON) { triNormal /= btSqrt(dot); for (int v = 0; v < 3; v++) { btVector3 pos = parentTransform*triangleVerts[v]; indicesOut.push_back(vertexPositions.size()); vertexPositions.push_back(pos); vertexNormals.push_back(triNormal); } } } } break; } default: { if (collisionShape->isConvex()) { btConvexShape* convex = (btConvexShape*)collisionShape; { btShapeHull* hull = new btShapeHull(convex); hull->buildHull(0.0, 1); { //int strideInBytes = 9*sizeof(float); //int numVertices = hull->numVertices(); //int numIndices =hull->numIndices(); for (int t=0;tnumTriangles();t++) { btVector3 triNormal; int index0 = hull->getIndexPointer()[t*3+0]; int index1 = hull->getIndexPointer()[t*3+1]; int index2 = hull->getIndexPointer()[t*3+2]; btVector3 pos0 =parentTransform*hull->getVertexPointer()[index0]; btVector3 pos1 =parentTransform*hull->getVertexPointer()[index1]; btVector3 pos2 =parentTransform*hull->getVertexPointer()[index2]; triNormal = (pos1-pos0).cross(pos2-pos0); triNormal.normalize(); for (int v=0;v<3;v++) { int index = hull->getIndexPointer()[t*3+v]; btVector3 pos =parentTransform*hull->getVertexPointer()[index]; indicesOut.push_back(vertexPositions.size()); vertexPositions.push_back(pos); vertexNormals.push_back(triNormal); } } } delete hull; } } else { if (collisionShape->isCompound()) { btCompoundShape* compound = (btCompoundShape*) collisionShape; for (int i=0;igetNumChildShapes();i++) { btTransform childWorldTrans = parentTransform * compound->getChildTransform(i); CollisionShape2TriangleMesh(compound->getChildShape(i),childWorldTrans,vertexPositions,vertexNormals,indicesOut); } } else { btAssert(0); } } } }; }