| 280 | } |
| 281 | |
| 282 | void NodeParser::extract_faces_from_voxels() { |
| 283 | if (m_vertex_per_voxel != 4) { |
| 284 | throw NotImplementedError("Only tet element is supported"); |
| 285 | } |
| 286 | m_faces.clear(); |
| 287 | |
| 288 | typedef std::map<Triplet, unsigned short> FaceCounter; |
| 289 | FaceCounter face_counter; |
| 290 | for (const auto& voxel : m_voxels) { |
| 291 | assert(voxel.size() == 4); |
| 292 | Triplet voxel_faces[4] = { |
| 293 | Triplet(voxel[0], voxel[2], voxel[1]), |
| 294 | Triplet(voxel[0], voxel[1], voxel[3]), |
| 295 | Triplet(voxel[0], voxel[3], voxel[2]), |
| 296 | Triplet(voxel[1], voxel[2], voxel[3]) |
| 297 | }; |
| 298 | |
| 299 | for (size_t j=0; j<4; j++) { |
| 300 | if (face_counter.find(voxel_faces[j]) == face_counter.end()) { |
| 301 | face_counter[voxel_faces[j]] = 1; |
| 302 | } else { |
| 303 | face_counter[voxel_faces[j]] += 1; |
| 304 | } |
| 305 | } |
| 306 | } |
| 307 | |
| 308 | std::vector<int> vertex_buffer; |
| 309 | for (FaceCounter::const_iterator itr = face_counter.begin(); |
| 310 | itr!=face_counter.end(); itr++) { |
| 311 | assert(itr->second == 1 || itr->second == 2); |
| 312 | if (itr->second == 1) { |
| 313 | const VectorI& f = itr->first.get_ori_data(); |
| 314 | m_faces.push_back(f); |
| 315 | } |
| 316 | } |
| 317 | m_num_faces = m_faces.size(); |
| 318 | m_vertex_per_face = 3; |
| 319 | } |