// -----------------------------------------------------------------------
// compute the links between the surface mesh and tetrahedras
void ObjMesh::buildTetraLinks(const NxVec3 *vertices, const NxU32 *indices, const NxU32 numTets)
{
if(!mTetraLinks.empty())
return;
mTetraLinks.clear();
MeshHash* hash = new MeshHash();
// hash tetrahedra for faster search
hash->setGridSpacing(mBounds.min.distance(mBounds.max) * 0.1f);
for (NxU32 i = 0; i < numTets; i++) {
const NxU32 *ix = &indices[4*i];
NxBounds3 tetraBounds;
tetraBounds.setEmpty();
tetraBounds.include(vertices[*ix++]);
tetraBounds.include(vertices[*ix++]);
tetraBounds.include(vertices[*ix++]);
tetraBounds.include(vertices[*ix++]);
hash->add(tetraBounds, i);
}
for (NxU32 i = 0; i < mVertices.size(); i++) {
// prepare datastructure for drained tetras
mDrainedTriVertices.push_back(false);
ObjMeshTetraLink tmpLink;
NxVec3 triVert = mVertices[i];
std::vector<int> itemIndices;
hash->queryUnique(triVert, itemIndices);
NxReal minDist = 0.0f;
NxVec3 b;
int num, isize;
num = isize = itemIndices.size();
if (num == 0) num = numTets;
for (int i = 0; i < num; i++) {
int j = i;
if (isize > 0) j = itemIndices[i];
const NxU32 *ix = &indices[j*4];
const NxVec3 &p0 = vertices[*ix++];
const NxVec3 &p1 = vertices[*ix++];
const NxVec3 &p2 = vertices[*ix++];
const NxVec3 &p3 = vertices[*ix++];
NxVec3 b = computeBaryCoords(triVert, p0, p1, p2, p3);
// is the vertex inside the tetrahedron? If yes we take it
if (b.x >= 0.0f && b.y >= 0.0f && b.z >= 0.0f && (b.x + b.y + b.z) <= 1.0f) {
tmpLink.barycentricCoords = b;
tmpLink.tetraNr = j;
break;
}
// otherwise, if we are not in any tetrahedron we take the closest one
NxReal dist = 0.0f;
if (b.x + b.y + b.z > 1.0f) dist = b.x + b.y + b.z - 1.0f;
if (b.x < 0.0f) dist = (-b.x < dist) ? dist : -b.x;
if (b.y < 0.0f) dist = (-b.y < dist) ? dist : -b.y;
if (b.z < 0.0f) dist = (-b.z < dist) ? dist : -b.z;
if (i == 0 || dist < minDist) {
minDist = dist;
tmpLink.barycentricCoords = b;
tmpLink.tetraNr = j;
}
}
mTetraLinks.push_back(tmpLink);
}
delete hash;
}
// to attach to tetra mesh
void TetraMeshHelper::buildTetraLinks(const NxSoftBodyMeshDesc& desc)
{
const NxVec3 *vertices = (const NxVec3 *) desc.vertices;
const void *tetIndices = desc.tetrahedra;
bool is32Bits = !(desc.flags & NX_SOFTBODY_MESH_16_BIT_INDICES);
const NxU32 numTets = desc.numTetrahedra;
mTetraLinks.clear();
MeshHash* hash = new MeshHash();
// hash tetrahedra for faster search
hash->setGridSpacing(mBounds.min.distance(mBounds.max) * 0.1f);
NxU8* startIndex = (NxU8*) tetIndices;
if(is32Bits)
{
for (NxU32 i = 0; i < numTets; i++) {
const NxU32 *ix = ((NxU32*) startIndex) + 4*i;
NxBounds3 tetraBounds;
tetraBounds.setEmpty();
tetraBounds.include(vertices[*ix++]);
tetraBounds.include(vertices[*ix++]);
tetraBounds.include(vertices[*ix++]);
tetraBounds.include(vertices[*ix++]);
hash->add(tetraBounds, i);
}
for (NxU32 i = 0; i < maxMesh.numVerts; i++)
{
MeshTetraLink tmpLink;
NxVec3 triVert(maxMesh.verts[i].x, maxMesh.verts[i].y, maxMesh.verts[i].z);
std::vector<int> itemIndices;
hash->queryUnique(triVert, itemIndices);
NxReal minDist = 0.0f;
NxVec3 b;
int num, isize;
num = isize = itemIndices.size();
if (num == 0) num = numTets;
for (int i = 0; i < num; i++) {
int j = i;
if (isize > 0) j = itemIndices[i];
const NxU32 *ix = ((NxU32*) startIndex) + 4*j;
const NxVec3 &p0 = vertices[*ix++];
const NxVec3 &p1 = vertices[*ix++];
const NxVec3 &p2 = vertices[*ix++];
const NxVec3 &p3 = vertices[*ix++];
NxVec3 b = computeBaryCoords(triVert, p0, p1, p2, p3);
// is the vertex inside the tetrahedron? If yes we take it
if (b.x >= 0.0f && b.y >= 0.0f && b.z >= 0.0f && (b.x + b.y + b.z) <= 1.0f) {
tmpLink.barycentricCoords = b;
tmpLink.tetraNr = j;
break;
}
// otherwise, if we are not in any tetrahedron we take the closest one
NxReal dist = 0.0f;
if (b.x + b.y + b.z > 1.0f) dist = b.x + b.y + b.z - 1.0f;
if (b.x < 0.0f) dist = (-b.x < dist) ? dist : -b.x;
if (b.y < 0.0f) dist = (-b.y < dist) ? dist : -b.y;
if (b.z < 0.0f) dist = (-b.z < dist) ? dist : -b.z;
if (i == 0 || dist < minDist) {
minDist = dist;
tmpLink.barycentricCoords = b;
tmpLink.tetraNr = j;
}
}
mTetraLinks.push_back(tmpLink);
}
}
else
{
for (NxU32 i = 0; i < numTets; i++) {
const NxU16 *ix = ((NxU16*) startIndex) + 4*i;
NxBounds3 tetraBounds;
tetraBounds.setEmpty();
tetraBounds.include(vertices[*ix++]);
tetraBounds.include(vertices[*ix++]);
tetraBounds.include(vertices[*ix++]);
tetraBounds.include(vertices[*ix++]);
hash->add(tetraBounds, i);
}
for (NxU32 i = 0; i < maxMesh.numVerts; i++)
{
MeshTetraLink tmpLink;
NxVec3 triVert(maxMesh.verts[i].x, maxMesh.verts[i].y, maxMesh.verts[i].z);
std::vector<int> itemIndices;
hash->queryUnique(triVert, itemIndices);
NxReal minDist = 0.0f;
NxVec3 b;
int num, isize;
num = isize = itemIndices.size();
if (num == 0) num = numTets;
for (int i = 0; i < num; i++) {
int j = i;
if (isize > 0) j = itemIndices[i];
const NxU16 *ix = ((NxU16*) startIndex) + 4*j;
const NxVec3 &p0 = vertices[*ix++];
const NxVec3 &p1 = vertices[*ix++];
const NxVec3 &p2 = vertices[*ix++];
const NxVec3 &p3 = vertices[*ix++];
NxVec3 b = computeBaryCoords(triVert, p0, p1, p2, p3);
// is the vertex inside the tetrahedron? If yes we take it
if (b.x >= 0.0f && b.y >= 0.0f && b.z >= 0.0f && (b.x + b.y + b.z) <= 1.0f) {
tmpLink.barycentricCoords = b;
tmpLink.tetraNr = j;
break;
}
// otherwise, if we are not in any tetrahedron we take the closest one
NxReal dist = 0.0f;
if (b.x + b.y + b.z > 1.0f) dist = b.x + b.y + b.z - 1.0f;
if (b.x < 0.0f) dist = (-b.x < dist) ? dist : -b.x;
if (b.y < 0.0f) dist = (-b.y < dist) ? dist : -b.y;
if (b.z < 0.0f) dist = (-b.z < dist) ? dist : -b.z;
if (i == 0 || dist < minDist) {
minDist = dist;
tmpLink.barycentricCoords = b;
tmpLink.tetraNr = j;
}
}
mTetraLinks.push_back(tmpLink);
}
}
delete hash;
}
