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(const aiNode &node, GLuint progId, AnimMap *am): ai(node), progId(progId), animMap(am) {
 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                 const aiNode *child = node.mChildren[i];
 124                 children.push_back(new Node(*child, progId, am));
 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 void Model::Node::draw( const std::vector<Mesh> &meshes,
 228                                                 const std::vector<Material> &materials,
 229                                                 const Skybox skybox,
 230                                                 const float tick,
 231                                                 const BoneTransforms &boneTransforms,
 232                                                 glm::mat4 parentTrans = glm::mat4(1)) const {
 233
 234         GLuint modelLoc = glGetUniformLocation(progId, "model");
 235         glm::mat4 m = totalTrans(parentTrans, tick);
 236
 237 #ifdef DEBUG_NODES
 238         drawDebugNode(m);
 239 #endif
 240
 241         for (unsigned int i: meshIndices) {
 242                 const Mesh &mesh = meshes[i];
 243                 glBindVertexArray(mesh.vao);
 244
 245                 // bones
 246                 std::vector<glm::mat4> idBones(17, glm::mat4(1.f));
 247                 glUniformMatrix4fv(glGetUniformLocation(progId, "bones"), 17, GL_FALSE, glm::value_ptr(idBones[0]));
 248
 249                 // bonemap: map from bone nodes to bone ids and aiBones
 250                 for (auto pair: mesh.boneMap) {
 251
 252                         std::string boneName = pair.first;
 253
 254                         unsigned int boneId = pair.second.first;
 255                         aiBone *bone = pair.second.second;
 256                         // This is actually an inverse-bind matrix
 257                         // i.e. transforms bone space -> mesh space
 258                         // so no need to inverse again!
 259                         // https://github.com/assimp/assimp/pull/1803/files
 260                         glm::mat4 boneOffset = aiMatrixToMat4(bone->mOffsetMatrix);
 261
 262                         if (!boneTransforms.count(boneName)) abort();
 263                         glm::mat4 boneTrans = boneTransforms.at(boneName);
 264
 265                         boneTrans = boneTrans * boneOffset;
 266
 267                         std::string boneLocStr = "bones[" + std::to_string(boneId) + "]";
 268                         GLuint boneLoc = glGetUniformLocation(progId, boneLocStr.c_str());
 269                         glUniformMatrix4fv(boneLoc, 1, GL_FALSE, glm::value_ptr(boneTrans));
 270                 }
 271
 272                 Material material = materials[mesh.materialIndex];
 273                 material.bind();
 274
 275                 glUniform1i(glGetUniformLocation(progId, "irradianceMap"), 4);
 276                 glActiveTexture(GL_TEXTURE4);
 277                 glBindTexture(GL_TEXTURE_CUBE_MAP, skybox.getIrradianceMap());
 278
 279                 glUniform1i(glGetUniformLocation(progId, "prefilterMap"), 5);
 280                 glActiveTexture(GL_TEXTURE5);
 281                 glBindTexture(GL_TEXTURE_CUBE_MAP, skybox.getPrefilterMap());
 282
 283                 glUniform1i(glGetUniformLocation(progId, "brdfMap"), 6);
 284                 glActiveTexture(GL_TEXTURE6);
 285                 glBindTexture(GL_TEXTURE_2D, skybox.getBRDFMap());
 286
 287                 glUniformMatrix4fv(modelLoc, 1, GL_FALSE, glm::value_ptr(m));
 288
 289                 glDrawElements(GL_TRIANGLES, mesh.numIndices, GL_UNSIGNED_INT, 0);
 290         }
 291         for (Node *child: children) child->draw(meshes, materials, skybox, tick, boneTransforms, m);
 292 }
 293
 294 void printMatrix4x4(aiMatrix4x4 m) {
 295         fprintf(stderr, "%f, %f, %f, %f\n", m.a1, m.a2, m.a3, m.a4);
 296         fprintf(stderr, "%f, %f, %f, %f\n", m.b1, m.b2, m.b3, m.b4);
 297         fprintf(stderr, "%f, %f, %f, %f\n", m.c1, m.c2, m.c3, m.c4);
 298         fprintf(stderr, "%f, %f, %f, %f\n", m.d1, m.d2, m.d3, m.d4);
 299 }
 300
 301 void printHierarchy(aiNode *n, int indent = 0) {
 302         for (int i = 0; i < indent; i++)
 303                 fprintf(stderr, "\t");
 304         fprintf(stderr,"%s\n", n->mName.C_Str());
 305         printMatrix4x4(n->mTransformation);
 306         for (int i = 0; i < n->mNumChildren; i++)
 307                 printHierarchy(n->mChildren[i], indent + 1);
 308 }
 309
 310 Model::Model(const aiScene *scene, Program p): program(p) {
 311         glUseProgram(p.progId);
 312
 313         for (int i = 0; i < scene->mNumMeshes; i++) {
 314                 const aiMesh *mesh = scene->mMeshes[i];
 315                 meshes.push_back(Mesh(mesh, p.progId));
 316         }
 317
 318         for (unsigned int i = 0; i < scene->mNumMaterials; i++) {
 319                 const aiMaterial &material = *scene->mMaterials[i];
 320                 materials.push_back(Material(material, *scene, p.progId));
 321         }
 322
 323         for (int i = 0; i < scene->mNumAnimations; i++) {
 324                 const aiAnimation *aiAnim = scene->mAnimations[i];
 325
 326                 std::map<std::string, std::vector<const aiNodeAnim*>> nodeAnims;
 327
 328                 for (int j = 0; j < aiAnim->mNumChannels; j++) {
 329                         const aiNodeAnim *nodeAnim = aiAnim->mChannels[j];
 330                         std::string nodeName = std::string(nodeAnim->mNodeName.C_Str());
 331
 332                         if (!nodeAnims.count(nodeName)) nodeAnims[nodeName] = std::vector<const aiNodeAnim*>();
 333
 334                         nodeAnims[nodeName].push_back(nodeAnim);
 335                 }
 336
 337                 for (std::pair<std::string, std::vector<const aiNodeAnim*>> pair: nodeAnims) {
 338                         std::string nodeName = pair.first;
 339
 340                         if (!animMap.count(nodeName)) animMap[nodeName] = std::vector<const Animation>();
 341                         animMap[nodeName].push_back({ aiAnim->mDuration, pair.second });
 342                 }
 343         }
 344
 345         root = new Node(*(scene->mRootNode), p.progId, &animMap);
 346 }
 347
 348
 349 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 {
 350         std::string name = std::string(n.ai.mName.C_Str());
 351
 352         glm::mat4 m = n.totalTrans(parentTrans, tick);
 353
 354         BoneTransforms res;
 355         if (bones.count(name) > 0)
 356                 res[std::string(n.ai.mName.C_Str())] = m; // take part in hierarchy
 357         else
 358                 m = glm::mat4(1); // ignore this node transformation
 359         for (const auto child: n.getChildren())
 360                 res.merge(calcBoneTransforms(*child, tick, bones, m));
 361         return res;
 362 }
 363
 364 void Model::draw(Skybox skybox, const float tick) const {
 365         glUseProgram(program.progId);
 366
 367         std::set<std::string> bones;
 368         for (auto m: this->meshes) {
 369                 for (auto b: m.boneMap) {
 370                         bones.insert(b.first);
 371                 }
 372         }
 373         auto boneTransforms = calcBoneTransforms(*root, tick, bones);
 374
 375         root->draw(meshes, materials, skybox, tick, boneTransforms);
 376 }
 377
 378 Model::Node* Model::find(const std::string &name) const {
 379         return find(aiString(name));
 380 }
 381
 382 Model::Node* Model::find(const aiString name) const {
 383         const aiNode *node = root->ai.FindNode(name);
 384         Model::Node* res = root->findNode(*node);
 385         return res;
 386 }
 387
 388 Model::Node* Model::Node::findNode(const aiNode &aiNode) {
 389         if (&ai == &aiNode) return this;
 390         for (Model::Node *child: children) {
 391                 Model::Node *res = child->findNode(aiNode);
 392                 if (res) return res;
 393         }
 394         return nullptr;
 395 }