model.cpp

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