model.cpp

   1 #include "model.hpp"
   2 #include <iostream>
   3 #include <assimp/quaternion.h>
   4 #include <glm/gtc/type_ptr.hpp>
   5 #include <glm/gtx/closest_point.hpp>
   6 #include "util.hpp"
   7
   8 Model::Mesh::Mesh(const aiMesh *aiMesh, GLuint progId) : progId(progId), ai(*aiMesh) {
   9         std::vector<glm::vec3> vertices, normals, tangents, bitangents;
  10         std::vector<glm::vec2> texCoords;
  11
  12         for (int i = 0; i < aiMesh->mNumVertices; i++) {
  13                 if (aiMesh->HasPositions()) {
  14                         aiVector3D v = aiMesh->mVertices[i];
  15                         vertices.push_back(glm::vec3(v.x, v.y, v.z));
  16                 }
  17                 if (aiMesh->HasNormals()) {
  18                         aiVector3D v = aiMesh->mNormals[i];
  19                         normals.push_back(glm::vec3(v.x, v.y, v.z));
  20                 } else {
  21                         std::cerr << "Missing normals" << std::endl;
  22                         abort();
  23                 }
  24                 // check for texture coord set 0
  25                 if (aiMesh->HasTextureCoords(0)) {
  26                         const aiVector3D v = aiMesh->mTextureCoords[0][i];
  27                         texCoords.push_back(glm::vec2(v.x, v.y));
  28                 } else {
  29                         texCoords.push_back(glm::vec2(0));
  30                 }
  31                 materialIndex = aiMesh->mMaterialIndex;
  32         }
  33
  34         std::vector<GLuint> indices;
  35
  36         for (int i = 0; i < aiMesh->mNumFaces; i++) {
  37                 const aiFace &face = aiMesh->mFaces[i];
  38                 if(face.mNumIndices == 3) {
  39                         indices.push_back(face.mIndices[0]);
  40                         indices.push_back(face.mIndices[1]);
  41                         indices.push_back(face.mIndices[2]);
  42                 }
  43         }
  44
  45         numIndices = indices.size();
  46
  47         glGenVertexArrays(1, &vao);
  48         glBindVertexArray(vao);
  49
  50         glGenBuffers(6, vbos);
  51         GLuint posVbo = vbos[0], normalVbo = vbos[1], texCoordVbo = vbos[2], indicesVbo = vbos[3];
  52         GLuint boneVbo = vbos[4];
  53
  54         GLuint posLoc = glGetAttribLocation(progId, "pos");
  55         glBindBuffer(GL_ARRAY_BUFFER, posVbo);
  56         glBufferData(GL_ARRAY_BUFFER, vertices.size() * sizeof(glm::vec3), &vertices[0], GL_STATIC_DRAW);
  57         glEnableVertexAttribArray(posLoc);
  58         glVertexAttribPointer(posLoc, 3, GL_FLOAT, GL_FALSE, 0, 0);
  59
  60         GLuint normalLoc = glGetAttribLocation(progId, "unscaledNormal");
  61         glBindBuffer(GL_ARRAY_BUFFER, normalVbo);
  62         glBufferData(GL_ARRAY_BUFFER, normals.size() * sizeof(glm::vec3), &normals[0], GL_STATIC_DRAW);
  63         glEnableVertexAttribArray(normalLoc);
  64         glVertexAttribPointer(normalLoc, 3, GL_FLOAT, GL_FALSE, 0, 0);
  65
  66         GLuint texCoordLoc = glGetAttribLocation(progId, "vTexCoord");
  67         glBindBuffer(GL_ARRAY_BUFFER, texCoordVbo);
  68         glBufferData(GL_ARRAY_BUFFER, texCoords.size() * sizeof(glm::vec2), &texCoords[0], GL_STATIC_DRAW);
  69         glEnableVertexAttribArray(texCoordLoc);
  70         glVertexAttribPointer(texCoordLoc, 2, GL_FLOAT, GL_FALSE, 0, 0);
  71
  72         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indicesVbo);
  73         glBufferData(GL_ELEMENT_ARRAY_BUFFER, indices.size() * sizeof(GLuint), &indices[0], GL_STATIC_DRAW);
  74
  75         // bones
  76         std::vector<VertBones> vertBones(aiMesh->mNumVertices);
  77
  78         std::map<unsigned int, std::vector<std::pair<unsigned int, float>>> boneWeightMap;
  79
  80         for (unsigned int i = 0; i < aiMesh->mNumBones; i++) {
  81                 aiBone *aiBone = aiMesh->mBones[i];
  82
  83                 boneMap[std::string(aiBone->mName.C_Str())] = std::pair(i + 1, aiBone);
  84
  85                 for (int j = 0; j < aiBone->mNumWeights; j++) {
  86                         aiVertexWeight vw = aiBone->mWeights[j];
  87
  88                         if (!boneWeightMap.count(vw.mVertexId))
  89                                 boneWeightMap[vw.mVertexId] = std::vector<std::pair<unsigned int, float>>();
  90                         boneWeightMap[vw.mVertexId].push_back(std::pair(i + 1, vw.mWeight));
  91                 }
  92         }
  93
  94         for (auto pair: boneWeightMap) {
  95                 unsigned int vertexId = pair.first;
  96                 for (int i = 0; i < pair.second.size() && i < 4; i++) {
  97                         unsigned int boneId = pair.second[i].first;
  98                         float weight = pair.second[i].second;
  99                         vertBones[vertexId].ids[i] = boneId;
 100                         vertBones[vertexId].weights[i] = weight;
 101                 }
 102         }
 103
 104         glBindBuffer(GL_ARRAY_BUFFER, boneVbo);
 105         glBufferData(GL_ARRAY_BUFFER, sizeof(VertBones) * vertBones.size(), &vertBones[0], GL_STATIC_DRAW);
 106
 107         GLuint boneIdLoc = glGetAttribLocation(progId, "boneIds");
 108         glEnableVertexAttribArray(boneIdLoc);
 109         glVertexAttribIPointer(boneIdLoc, 4, GL_INT, sizeof(VertBones), 0);
 110
 111         GLuint boneWeightLoc = glGetAttribLocation(progId, "boneWeights");
 112         glEnableVertexAttribArray(boneWeightLoc);
 113         glVertexAttribPointer(boneWeightLoc, 4, GL_FLOAT, GL_FALSE, sizeof(VertBones), (const GLvoid *)sizeof(VertBones::ids));
 114 }
 115
 116 void Model::Mesh::updatePosBuffer() const {
 117         GLuint posLoc = glGetAttribLocation(progId, "pos");
 118         GLuint posVbo = vbos[0];
 119         glBindBuffer(GL_ARRAY_BUFFER, posVbo);
 120         glBufferData(GL_ARRAY_BUFFER, ai.mNumVertices * sizeof(aiVector3D), ai.mVertices, GL_STATIC_DRAW);
 121         glEnableVertexAttribArray(posLoc);
 122         glVertexAttribPointer(posLoc, 3, GL_FLOAT, GL_FALSE, 0, 0);
 123 }
 124
 125 Model::Node::Node(aiNode &node, GLuint progId, AnimMap *am, std::set<std::string> allBones, Node *p): ai(node), parent(p), progId(progId), animMap(am), isBone(allBones.count(std::string(node.mName.C_Str())) > 0) {
 126         for (int i = 0; i < node.mNumMeshes; i++) {
 127                 meshIndices.push_back(node.mMeshes[i]);
 128         }
 129         for (int i = 0; i < node.mNumChildren; i++) {
 130                 aiNode *child = node.mChildren[i];
 131                 children.push_back(new Node(*child, progId, am, allBones, this));
 132         }
 133 }
 134
 135 glm::mat4 lerpPosition(const aiNodeAnim *anim, const float tick) {
 136         if (anim->mNumPositionKeys == 0) return glm::mat4(1.f);
 137
 138         int yIndex = -1;
 139         for (int i = 0; i < anim->mNumPositionKeys; i++) {
 140                 aiVectorKey vk = anim->mPositionKeys[i];
 141                 if (vk.mTime > tick) {
 142                         yIndex = i;
 143                         break;
 144                 }
 145         }
 146         aiVector3D lerpPos;
 147         if (yIndex == 0) {
 148                 lerpPos = anim->mPositionKeys[0].mValue;
 149         } else if (yIndex == -1) {
 150                 lerpPos = anim->mPositionKeys[anim->mNumPositionKeys - 1].mValue;
 151         } else {
 152                 auto X = anim->mPositionKeys[yIndex - 1];
 153                 auto Y = anim->mPositionKeys[yIndex];
 154
 155                 lerpPos = (X.mValue * (float)(Y.mTime - tick) + Y.mValue * (float)(tick - X.mTime)) / (float)(Y.mTime - X.mTime);
 156         }
 157         aiMatrix4x4 result;
 158         aiMatrix4x4::Translation(lerpPos, result);
 159         return aiMatrixToMat4(result);
 160 }
 161
 162 glm::mat4 lerpRotation(const aiNodeAnim *anim, const float tick) {
 163         int yIndex = -1;
 164         for (int i = 0; i < anim->mNumRotationKeys; i++) {
 165                 aiQuatKey vk = anim->mRotationKeys[i];
 166                 if (vk.mTime > tick) {
 167                         yIndex = i;
 168                         break;
 169                 }
 170         }
 171
 172         aiQuaternion result;
 173         if (yIndex < 1) {
 174                 result = anim->mRotationKeys[0].mValue;
 175         } else if (yIndex == -1) {
 176                 result = anim->mRotationKeys[anim->mNumRotationKeys - 1].mValue;
 177         } else {
 178
 179                 auto X = anim->mRotationKeys[yIndex - 1];
 180                 auto Y = anim->mRotationKeys[yIndex];
 181
 182                 float mix = (tick - X.mTime) / (Y.mTime - X.mTime);
 183
 184                 aiQuaternion::Interpolate(result, X.mValue, Y.mValue, mix);
 185
 186         }
 187         return aiMatrixToMat4(aiMatrix4x4(result.GetMatrix()));
 188 }
 189
 190 glm::mat4 lerpScaling(const aiNodeAnim *anim, const float tick) {
 191         int yIndex = -1;
 192         for (int i = 0; i < anim->mNumScalingKeys; i++) {
 193                 aiVectorKey vk = anim->mScalingKeys[i];
 194                 if (vk.mTime > tick) {
 195                         yIndex = i;
 196                         break;
 197                 }
 198         }
 199
 200         aiVector3D lerpPos;
 201         if (yIndex < 1) {
 202                 lerpPos = anim->mScalingKeys[0].mValue;
 203         } else {
 204                 auto X = anim->mScalingKeys[yIndex - 1];
 205                 auto Y = anim->mScalingKeys[yIndex];
 206
 207                 lerpPos = (X.mValue * (float)(Y.mTime - tick) + Y.mValue * (float)(tick - X.mTime)) / (float)(Y.mTime - X.mTime);
 208         }
 209         aiMatrix4x4 result;
 210         aiMatrix4x4::Scaling(lerpPos, result);
 211         return aiMatrixToMat4(result);
 212 }
 213
 214 glm::mat4 Model::Node::totalTrans(const glm::mat4 parentTrans, const float tick) const {
 215         glm::mat4 aiTrans = aiMatrixToMat4(ai.mTransformation);
 216         if (animMap->count(std::string(ai.mName.C_Str()))) {
 217                 for (const Animation anim: animMap->at(std::string(ai.mName.C_Str()))) {
 218                         // animations are *absolute*
 219                         // they replace aiNode.mTransformation!!
 220                         aiTrans = glm::mat4(1);
 221                         float t = fmod(tick, anim.duration);
 222                         for (const aiNodeAnim *nodeAnim: anim.nodeAnims) {
 223                                 aiTrans *= lerpPosition(nodeAnim, t);
 224                                 aiTrans *= lerpRotation(nodeAnim, t);
 225                                 aiTrans *= lerpScaling(nodeAnim, t);
 226                         }
 227                 }
 228         }
 229
 230         glm::mat4 m = parentTrans * aiTrans * transform;
 231         return m;
 232 }
 233
 234 const Model::Node &Model::Node::getRoot() const {
 235         const Model::Node *rootPtr = this;
 236         while (rootPtr->parent != nullptr)
 237                 rootPtr = rootPtr->parent;
 238         const Model::Node &root = *rootPtr;
 239         return root;
 240 }
 241
 242 void Model::Node::draw( const std::vector<Mesh> &meshes,
 243                                                 const std::vector<Material> &materials,
 244                                                 const Skybox skybox,
 245                                                 const float tick,
 246                                                 const BoneTransforms &boneTransforms,
 247                                                 glm::mat4 parentTrans = glm::mat4(1)) const {
 248
 249         GLuint modelLoc = glGetUniformLocation(progId, "model");
 250         glm::mat4 m = totalTrans(parentTrans, tick);
 251
 252 #ifdef DEBUG_NODES
 253         if (isBone)
 254                 drawDebugNode(m, {0, 0.5, 1, 1});
 255         else
 256                 drawDebugNode(m);
 257 #endif
 258
 259         for (unsigned int i: meshIndices) {
 260                 const Mesh &mesh = meshes[i];
 261                 glBindVertexArray(mesh.vao);
 262
 263                 // bones
 264                 std::vector<glm::mat4> idBones(17, glm::mat4(1.f));
 265                 glUniformMatrix4fv(glGetUniformLocation(progId, "bones"), 17, GL_FALSE, glm::value_ptr(idBones[0]));
 266
 267                 // bonemap: map from bone nodes to bone ids and aiBones
 268                 for (auto pair: mesh.boneMap) {
 269
 270                         std::string boneName = pair.first;
 271
 272                         unsigned int boneId = pair.second.first;
 273                         aiBone *bone = pair.second.second;
 274                         // This is actually an inverse-bind matrix
 275                         // i.e. transforms bone space -> mesh space
 276                         // so no need to inverse again!
 277                         // https://github.com/assimp/assimp/pull/1803/files
 278                         glm::mat4 boneOffset = aiMatrixToMat4(bone->mOffsetMatrix);
 279
 280                         if (!boneTransforms.count(boneName)) abort();
 281                         glm::mat4 boneTrans = boneTransforms.at(boneName);
 282
 283                         boneTrans = boneTrans * boneOffset;
 284
 285                         std::string boneLocStr = "bones[" + std::to_string(boneId) + "]";
 286                         GLuint boneLoc = glGetUniformLocation(progId, boneLocStr.c_str());
 287                         glUniformMatrix4fv(boneLoc, 1, GL_FALSE, glm::value_ptr(boneTrans));
 288                 }
 289
 290                 Material material = materials[mesh.materialIndex];
 291                 material.bind();
 292
 293                 glUniform1i(glGetUniformLocation(progId, "irradianceMap"), 4);
 294                 glActiveTexture(GL_TEXTURE4);
 295                 glBindTexture(GL_TEXTURE_CUBE_MAP, skybox.getIrradianceMap());
 296
 297                 glUniform1i(glGetUniformLocation(progId, "prefilterMap"), 5);
 298                 glActiveTexture(GL_TEXTURE5);
 299                 glBindTexture(GL_TEXTURE_CUBE_MAP, skybox.getPrefilterMap());
 300
 301                 glUniform1i(glGetUniformLocation(progId, "brdfMap"), 6);
 302                 glActiveTexture(GL_TEXTURE6);
 303                 glBindTexture(GL_TEXTURE_2D, skybox.getBRDFMap());
 304
 305                 glUniformMatrix4fv(modelLoc, 1, GL_FALSE, glm::value_ptr(m));
 306
 307                 glDrawElements(GL_TRIANGLES, mesh.numIndices, GL_UNSIGNED_INT, 0);
 308         }
 309         for (Node *child: children) child->draw(meshes, materials, skybox, tick, boneTransforms, m);
 310 }
 311
 312 void printHierarchy(aiNode *n, int indent = 0) {
 313         for (int i = 0; i < indent; i++)
 314                 fprintf(stderr, "\t");
 315         fprintf(stderr,"%s\n", n->mName.C_Str());
 316         printMatrix4x4(n->mTransformation);
 317         for (int i = 0; i < n->mNumChildren; i++)
 318                 printHierarchy(n->mChildren[i], indent + 1);
 319 }
 320
 321 Model::Model(const aiScene *scene, Program p): program(p) {
 322         glUseProgram(p.progId);
 323
 324         std::set<std::string> allBones;
 325         for (int i = 0; i < scene->mNumMeshes; i++) {
 326                 const aiMesh *mesh = scene->mMeshes[i];
 327                 meshes.push_back(Mesh(mesh, p.progId));
 328                 for (int j = 0; j < mesh->mNumBones; j++)
 329                         allBones.insert(std::string(mesh->mBones[j]->mName.C_Str()));
 330         }
 331
 332         for (unsigned int i = 0; i < scene->mNumMaterials; i++) {
 333                 const aiMaterial &material = *scene->mMaterials[i];
 334                 materials.push_back(Material(material, *scene, p.progId));
 335         }
 336
 337         for (int i = 0; i < scene->mNumAnimations; i++) {
 338                 const aiAnimation *aiAnim = scene->mAnimations[i];
 339
 340                 std::map<std::string, std::vector<const aiNodeAnim*>> nodeAnims;
 341
 342                 for (int j = 0; j < aiAnim->mNumChannels; j++) {
 343                         const aiNodeAnim *nodeAnim = aiAnim->mChannels[j];
 344                         std::string nodeName = std::string(nodeAnim->mNodeName.C_Str());
 345
 346                         if (!nodeAnims.count(nodeName)) nodeAnims[nodeName] = std::vector<const aiNodeAnim*>();
 347
 348                         nodeAnims[nodeName].push_back(nodeAnim);
 349                 }
 350
 351                 for (std::pair<std::string, std::vector<const aiNodeAnim*>> pair: nodeAnims) {
 352                         std::string nodeName = pair.first;
 353
 354                         if (!animMap.count(nodeName)) animMap[nodeName] = std::vector<const Animation>();
 355                         animMap[nodeName].push_back({ aiAnim->mDuration, pair.second });
 356                 }
 357         }
 358
 359         root = new Node(*(scene->mRootNode), p.progId, &animMap, allBones, nullptr);
 360 }
 361
 362
 363 std::map<std::string, glm::mat4> Model::calcBoneTransforms(const Node &n, const float tick, const std::set<std::string> bones, const glm::mat4 parentTrans = glm::mat4(1)) const {
 364         std::string name = std::string(n.ai.mName.C_Str());
 365
 366         glm::mat4 m = n.totalTrans(parentTrans, tick);
 367
 368         BoneTransforms res;
 369         if (bones.count(name) > 0)
 370                 res[std::string(n.ai.mName.C_Str())] = m; // take part in hierarchy
 371         else
 372                 m = glm::mat4(1); // ignore this node transformation
 373         for (const auto child: n.getChildren())
 374                 res.merge(calcBoneTransforms(*child, tick, bones, m));
 375         return res;
 376 }
 377
 378 void Model::draw(Skybox skybox, const float tick) const {
 379         glUseProgram(program.progId);
 380
 381         std::set<std::string> bones;
 382         for (auto m: this->meshes) {
 383                 for (auto b: m.boneMap) {
 384                         bones.insert(b.first);
 385                 }
 386         }
 387         auto boneTransforms = calcBoneTransforms(*root, tick, bones);
 388
 389         root->draw(meshes, materials, skybox, tick, boneTransforms);
 390 }
 391
 392 Model::Node* Model::find(const std::string &name) const {
 393         return find(aiString(name));
 394 }
 395
 396 Model::Node* Model::find(const aiString name) const {
 397         const aiNode *node = root->ai.FindNode(name);
 398         Model::Node* res = root->findNode(*node);
 399         return res;
 400 }
 401
 402 Model::Node* Model::Node::findNode(const aiNode &aiNode) {
 403         if (&ai == &aiNode) return this;
 404         for (Model::Node *child: children) {
 405                 Model::Node *res = child->findNode(aiNode);
 406                 if (res) return res;
 407         }
 408         return nullptr;
 409 }
 410
 411 bool Model::Node::operator==(const Model::Node &rhs) const {
 412         return &ai == &rhs.ai;
 413 }
 414
 415 // Returns closest vertex in world space and distance
 416 // a and b define the line in 3d space
 417 std::pair<glm::vec3, float> Model::closestVertex(Model::Node &n, glm::vec3 a, glm::vec3 b, glm::mat4 parentTrans) const {
 418         float closestDist = FLT_MAX;
 419         glm::vec3 closestVert;
 420
 421         for (int i = 0; i < n.ai.mNumMeshes; i++) {
 422                 int meshIdx = n.ai.mMeshes[i];
 423                 const aiMesh &mesh = meshes[meshIdx].ai;
 424
 425                 for (int j = 0; j < mesh.mNumVertices; j++) {
 426                         if (mesh.HasNormals()) {
 427                                 auto n = aiVector3DToVec3(mesh.mNormals[j]);
 428                                 if (glm::dot(n, glm::normalize(b - a)) > 0)
 429                                         continue;
 430                         }
 431                         glm::vec4 vPos = glm::vec4(aiVector3DToVec3(mesh.mVertices[j]), 1);
 432                         // Move from model space -> world space
 433                         vPos = parentTrans * aiMatrixToMat4(n.ai.mTransformation) * vPos;
 434                         float dist = glm::distance(glm::vec3(vPos),
 435                                                         glm::closestPointOnLine(glm::vec3(vPos), a, b));
 436                         if (dist < closestDist) {
 437                                 closestVert = glm::vec3(vPos);
 438                                 closestDist = dist;
 439                         }
 440                 }
 441         }
 442
 443         for (auto child: n.getChildren()) {
 444                 auto childRes = closestVertex(*child, a, b, parentTrans * aiMatrixToMat4(n.ai.mTransformation));
 445                 if (childRes.second < closestDist) {
 446                         closestVert = childRes.first;
 447                         closestDist = childRes.second;
 448                 }
 449         }
 450
 451         return { closestVert, closestDist };
 452 }