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) : 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         GLuint vbos[6];
  51         glGenBuffers(6, vbos);
  52         GLuint vertexVbo = vbos[0], normalVbo = vbos[1], texCoordVbo = vbos[2], indicesVbo = vbos[3];
  53         GLuint boneVbo = vbos[4];
  54
  55         GLuint posLoc = glGetAttribLocation(progId, "pos");
  56         glBindBuffer(GL_ARRAY_BUFFER, vertexVbo);
  57         glBufferData(GL_ARRAY_BUFFER, vertices.size() * sizeof(glm::vec3), &vertices[0], GL_STATIC_DRAW);
  58         glEnableVertexAttribArray(posLoc);
  59         glVertexAttribPointer(posLoc, 3, GL_FLOAT, GL_FALSE, 0, 0);
  60
  61         GLuint normalLoc = glGetAttribLocation(progId, "unscaledNormal");
  62         glBindBuffer(GL_ARRAY_BUFFER, normalVbo);
  63         glBufferData(GL_ARRAY_BUFFER, normals.size() * sizeof(glm::vec3), &normals[0], GL_STATIC_DRAW);
  64         glEnableVertexAttribArray(normalLoc);
  65         glVertexAttribPointer(normalLoc, 3, GL_FLOAT, GL_FALSE, 0, 0);
  66
  67         GLuint texCoordLoc = glGetAttribLocation(progId, "vTexCoord");
  68         glBindBuffer(GL_ARRAY_BUFFER, texCoordVbo);
  69         glBufferData(GL_ARRAY_BUFFER, texCoords.size() * sizeof(glm::vec2), &texCoords[0], GL_STATIC_DRAW);
  70         glEnableVertexAttribArray(texCoordLoc);
  71         glVertexAttribPointer(texCoordLoc, 2, GL_FLOAT, GL_FALSE, 0, 0);
  72
  73         glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indicesVbo);
  74         glBufferData(GL_ELEMENT_ARRAY_BUFFER, indices.size() * sizeof(GLuint), &indices[0], GL_STATIC_DRAW);
  75
  76         // bones
  77         std::vector<VertBones> vertBones(aiMesh->mNumVertices);
  78
  79         std::map<unsigned int, std::vector<std::pair<unsigned int, float>>> boneWeightMap;
  80
  81         for (unsigned int i = 0; i < aiMesh->mNumBones; i++) {
  82                 aiBone *aiBone = aiMesh->mBones[i];
  83
  84                 boneMap[std::string(aiBone->mName.C_Str())] = std::pair(i + 1, aiBone);
  85
  86                 for (int j = 0; j < aiBone->mNumWeights; j++) {
  87                         aiVertexWeight vw = aiBone->mWeights[j];
  88
  89                         if (!boneWeightMap.count(vw.mVertexId))
  90                                 boneWeightMap[vw.mVertexId] = std::vector<std::pair<unsigned int, float>>();
  91                         boneWeightMap[vw.mVertexId].push_back(std::pair(i + 1, vw.mWeight));
  92                 }
  93         }
  94
  95         for (auto pair: boneWeightMap) {
  96                 unsigned int vertexId = pair.first;
  97                 for (int i = 0; i < pair.second.size() && i < 4; i++) {
  98                         unsigned int boneId = pair.second[i].first;
  99                         float weight = pair.second[i].second;
 100                         vertBones[vertexId].ids[i] = boneId;
 101                         vertBones[vertexId].weights[i] = weight;
 102                 }
 103         }
 104
 105         glBindBuffer(GL_ARRAY_BUFFER, boneVbo);
 106         glBufferData(GL_ARRAY_BUFFER, sizeof(VertBones) * vertBones.size(), &vertBones[0], GL_STATIC_DRAW);
 107
 108         GLuint boneIdLoc = glGetAttribLocation(progId, "boneIds");
 109         glEnableVertexAttribArray(boneIdLoc);
 110         glVertexAttribIPointer(boneIdLoc, 4, GL_INT, sizeof(VertBones), 0);
 111
 112         GLuint boneWeightLoc = glGetAttribLocation(progId, "boneWeights");
 113         glEnableVertexAttribArray(boneWeightLoc);
 114         glVertexAttribPointer(boneWeightLoc, 4, GL_FLOAT, GL_FALSE, sizeof(VertBones), (const GLvoid *)sizeof(VertBones::ids));
 115 }
 116
 117 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) {
 118         for (int i = 0; i < node.mNumMeshes; i++) {
 119                 meshIndices.push_back(node.mMeshes[i]);
 120         }
 121         for (int i = 0; i < node.mNumChildren; i++) {
 122                 aiNode *child = node.mChildren[i];
 123                 children.push_back(new Node(*child, progId, am, allBones, this));
 124         }
 125 }
 126
 127 glm::mat4 lerpPosition(const aiNodeAnim *anim, const float tick) {
 128         if (anim->mNumPositionKeys == 0) return glm::mat4(1.f);
 129
 130         int yIndex = -1;
 131         for (int i = 0; i < anim->mNumPositionKeys; i++) {
 132                 aiVectorKey vk = anim->mPositionKeys[i];
 133                 if (vk.mTime > tick) {
 134                         yIndex = i;
 135                         break;
 136                 }
 137         }
 138         aiVector3D lerpPos;
 139         if (yIndex == 0) {
 140                 lerpPos = anim->mPositionKeys[0].mValue;
 141         } else if (yIndex == -1) {
 142                 lerpPos = anim->mPositionKeys[anim->mNumPositionKeys - 1].mValue;
 143         } else {
 144                 auto X = anim->mPositionKeys[yIndex - 1];
 145                 auto Y = anim->mPositionKeys[yIndex];
 146
 147                 lerpPos = (X.mValue * (float)(Y.mTime - tick) + Y.mValue * (float)(tick - X.mTime)) / (float)(Y.mTime - X.mTime);
 148         }
 149         aiMatrix4x4 result;
 150         aiMatrix4x4::Translation(lerpPos, result);
 151         return aiMatrixToMat4(result);
 152 }
 153
 154 glm::mat4 lerpRotation(const aiNodeAnim *anim, const float tick) {
 155         int yIndex = -1;
 156         for (int i = 0; i < anim->mNumRotationKeys; i++) {
 157                 aiQuatKey vk = anim->mRotationKeys[i];
 158                 if (vk.mTime > tick) {
 159                         yIndex = i;
 160                         break;
 161                 }
 162         }
 163
 164         aiQuaternion result;
 165         if (yIndex < 1) {
 166                 result = anim->mRotationKeys[0].mValue;
 167         } else if (yIndex == -1) {
 168                 result = anim->mRotationKeys[anim->mNumRotationKeys - 1].mValue;
 169         } else {
 170
 171                 auto X = anim->mRotationKeys[yIndex - 1];
 172                 auto Y = anim->mRotationKeys[yIndex];
 173
 174                 float mix = (tick - X.mTime) / (Y.mTime - X.mTime);
 175
 176                 aiQuaternion::Interpolate(result, X.mValue, Y.mValue, mix);
 177
 178         }
 179         return aiMatrixToMat4(aiMatrix4x4(result.GetMatrix()));
 180 }
 181
 182 glm::mat4 lerpScaling(const aiNodeAnim *anim, const float tick) {
 183         int yIndex = -1;
 184         for (int i = 0; i < anim->mNumScalingKeys; i++) {
 185                 aiVectorKey vk = anim->mScalingKeys[i];
 186                 if (vk.mTime > tick) {
 187                         yIndex = i;
 188                         break;
 189                 }
 190         }
 191
 192         aiVector3D lerpPos;
 193         if (yIndex < 1) {
 194                 lerpPos = anim->mScalingKeys[0].mValue;
 195         } else {
 196                 auto X = anim->mScalingKeys[yIndex - 1];
 197                 auto Y = anim->mScalingKeys[yIndex];
 198
 199                 lerpPos = (X.mValue * (float)(Y.mTime - tick) + Y.mValue * (float)(tick - X.mTime)) / (float)(Y.mTime - X.mTime);
 200         }
 201         aiMatrix4x4 result;
 202         aiMatrix4x4::Scaling(lerpPos, result);
 203         return aiMatrixToMat4(result);
 204 }
 205
 206 glm::mat4 Model::Node::totalTrans(const glm::mat4 parentTrans, const float tick) const {
 207         glm::mat4 aiTrans = aiMatrixToMat4(ai.mTransformation);
 208         if (animMap->count(std::string(ai.mName.C_Str()))) {
 209                 for (const Animation anim: animMap->at(std::string(ai.mName.C_Str()))) {
 210                         // animations are *absolute*
 211                         // they replace aiNode.mTransformation!!
 212                         aiTrans = glm::mat4(1);
 213                         float t = fmod(tick, anim.duration);
 214                         for (const aiNodeAnim *nodeAnim: anim.nodeAnims) {
 215                                 aiTrans *= lerpPosition(nodeAnim, t);
 216                                 aiTrans *= lerpRotation(nodeAnim, t);
 217                                 aiTrans *= lerpScaling(nodeAnim, t);
 218                         }
 219                 }
 220         }
 221
 222         glm::mat4 m = parentTrans * aiTrans * transform;
 223         return m;
 224 }
 225
 226 const Model::Node &Model::Node::getRoot() const {
 227         const Model::Node *rootPtr = this;
 228         while (rootPtr->parent != nullptr)
 229                 rootPtr = rootPtr->parent;
 230         const Model::Node &root = *rootPtr;
 231         return root;
 232 }
 233
 234 void Model::Node::draw( const std::vector<Mesh> &meshes,
 235                                                 const std::vector<Material> &materials,
 236                                                 const Skybox skybox,
 237                                                 const float tick,
 238                                                 const BoneTransforms &boneTransforms,
 239                                                 glm::mat4 parentTrans = glm::mat4(1)) const {
 240
 241         GLuint modelLoc = glGetUniformLocation(progId, "model");
 242         glm::mat4 m = totalTrans(parentTrans, tick);
 243
 244 #ifdef DEBUG_NODES
 245         if (isBone)
 246                 drawDebugNode(m, {0, 0.5, 1, 1});
 247         else
 248                 drawDebugNode(m);
 249 #endif
 250
 251         for (unsigned int i: meshIndices) {
 252                 const Mesh &mesh = meshes[i];
 253                 glBindVertexArray(mesh.vao);
 254
 255                 // bones
 256                 std::vector<glm::mat4> idBones(17, glm::mat4(1.f));
 257                 glUniformMatrix4fv(glGetUniformLocation(progId, "bones"), 17, GL_FALSE, glm::value_ptr(idBones[0]));
 258
 259                 // bonemap: map from bone nodes to bone ids and aiBones
 260                 for (auto pair: mesh.boneMap) {
 261
 262                         std::string boneName = pair.first;
 263
 264                         unsigned int boneId = pair.second.first;
 265                         aiBone *bone = pair.second.second;
 266                         // This is actually an inverse-bind matrix
 267                         // i.e. transforms bone space -> mesh space
 268                         // so no need to inverse again!
 269                         // https://github.com/assimp/assimp/pull/1803/files
 270                         glm::mat4 boneOffset = aiMatrixToMat4(bone->mOffsetMatrix);
 271
 272                         if (!boneTransforms.count(boneName)) abort();
 273                         glm::mat4 boneTrans = boneTransforms.at(boneName);
 274
 275                         boneTrans = boneTrans * boneOffset;
 276
 277                         std::string boneLocStr = "bones[" + std::to_string(boneId) + "]";
 278                         GLuint boneLoc = glGetUniformLocation(progId, boneLocStr.c_str());
 279                         glUniformMatrix4fv(boneLoc, 1, GL_FALSE, glm::value_ptr(boneTrans));
 280                 }
 281
 282                 Material material = materials[mesh.materialIndex];
 283                 material.bind();
 284
 285                 glUniform1i(glGetUniformLocation(progId, "irradianceMap"), 4);
 286                 glActiveTexture(GL_TEXTURE4);
 287                 glBindTexture(GL_TEXTURE_CUBE_MAP, skybox.getIrradianceMap());
 288
 289                 glUniform1i(glGetUniformLocation(progId, "prefilterMap"), 5);
 290                 glActiveTexture(GL_TEXTURE5);
 291                 glBindTexture(GL_TEXTURE_CUBE_MAP, skybox.getPrefilterMap());
 292
 293                 glUniform1i(glGetUniformLocation(progId, "brdfMap"), 6);
 294                 glActiveTexture(GL_TEXTURE6);
 295                 glBindTexture(GL_TEXTURE_2D, skybox.getBRDFMap());
 296
 297                 glUniformMatrix4fv(modelLoc, 1, GL_FALSE, glm::value_ptr(m));
 298
 299                 glDrawElements(GL_TRIANGLES, mesh.numIndices, GL_UNSIGNED_INT, 0);
 300         }
 301         for (Node *child: children) child->draw(meshes, materials, skybox, tick, boneTransforms, m);
 302 }
 303
 304 void printHierarchy(aiNode *n, int indent = 0) {
 305         for (int i = 0; i < indent; i++)
 306                 fprintf(stderr, "\t");
 307         fprintf(stderr,"%s\n", n->mName.C_Str());
 308         printMatrix4x4(n->mTransformation);
 309         for (int i = 0; i < n->mNumChildren; i++)
 310                 printHierarchy(n->mChildren[i], indent + 1);
 311 }
 312
 313 Model::Model(const aiScene *scene, Program p): program(p) {
 314         glUseProgram(p.progId);
 315
 316         std::set<std::string> allBones;
 317         for (int i = 0; i < scene->mNumMeshes; i++) {
 318                 const aiMesh *mesh = scene->mMeshes[i];
 319                 meshes.push_back(Mesh(mesh, p.progId));
 320                 for (int j = 0; j < mesh->mNumBones; j++)
 321                         allBones.insert(std::string(mesh->mBones[j]->mName.C_Str()));
 322         }
 323
 324         for (unsigned int i = 0; i < scene->mNumMaterials; i++) {
 325                 const aiMaterial &material = *scene->mMaterials[i];
 326                 materials.push_back(Material(material, *scene, p.progId));
 327         }
 328
 329         for (int i = 0; i < scene->mNumAnimations; i++) {
 330                 const aiAnimation *aiAnim = scene->mAnimations[i];
 331
 332                 std::map<std::string, std::vector<const aiNodeAnim*>> nodeAnims;
 333
 334                 for (int j = 0; j < aiAnim->mNumChannels; j++) {
 335                         const aiNodeAnim *nodeAnim = aiAnim->mChannels[j];
 336                         std::string nodeName = std::string(nodeAnim->mNodeName.C_Str());
 337
 338                         if (!nodeAnims.count(nodeName)) nodeAnims[nodeName] = std::vector<const aiNodeAnim*>();
 339
 340                         nodeAnims[nodeName].push_back(nodeAnim);
 341                 }
 342
 343                 for (std::pair<std::string, std::vector<const aiNodeAnim*>> pair: nodeAnims) {
 344                         std::string nodeName = pair.first;
 345
 346                         if (!animMap.count(nodeName)) animMap[nodeName] = std::vector<const Animation>();
 347                         animMap[nodeName].push_back({ aiAnim->mDuration, pair.second });
 348                 }
 349         }
 350
 351         root = new Node(*(scene->mRootNode), p.progId, &animMap, allBones, nullptr);
 352 }
 353
 354
 355 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 {
 356         std::string name = std::string(n.ai.mName.C_Str());
 357
 358         glm::mat4 m = n.totalTrans(parentTrans, tick);
 359
 360         BoneTransforms res;
 361         if (bones.count(name) > 0)
 362                 res[std::string(n.ai.mName.C_Str())] = m; // take part in hierarchy
 363         else
 364                 m = glm::mat4(1); // ignore this node transformation
 365         for (const auto child: n.getChildren())
 366                 res.merge(calcBoneTransforms(*child, tick, bones, m));
 367         return res;
 368 }
 369
 370 void Model::draw(Skybox skybox, const float tick) const {
 371         glUseProgram(program.progId);
 372
 373         std::set<std::string> bones;
 374         for (auto m: this->meshes) {
 375                 for (auto b: m.boneMap) {
 376                         bones.insert(b.first);
 377                 }
 378         }
 379         auto boneTransforms = calcBoneTransforms(*root, tick, bones);
 380
 381         root->draw(meshes, materials, skybox, tick, boneTransforms);
 382 }
 383
 384 Model::Node* Model::find(const std::string &name) const {
 385         return find(aiString(name));
 386 }
 387
 388 Model::Node* Model::find(const aiString name) const {
 389         const aiNode *node = root->ai.FindNode(name);
 390         Model::Node* res = root->findNode(*node);
 391         return res;
 392 }
 393
 394 Model::Node* Model::Node::findNode(const aiNode &aiNode) {
 395         if (&ai == &aiNode) return this;
 396         for (Model::Node *child: children) {
 397                 Model::Node *res = child->findNode(aiNode);
 398                 if (res) return res;
 399         }
 400         return nullptr;
 401 }
 402
 403 bool Model::Node::operator==(const Model::Node &rhs) const {
 404         return &ai == &rhs.ai;
 405 }
 406
 407 // Returns closest vertex in world space and distance
 408 // a and b define the line in 3d space
 409 std::pair<glm::vec3, float> Model::closestVertex(Model::Node &n, glm::vec3 a, glm::vec3 b, glm::mat4 parentTrans) const {
 410         float shortestDist = FLT_MAX;
 411         glm::vec3 closest;
 412         for (int i = 0; i < n.ai.mNumMeshes; i++) {
 413                 int meshIdx = n.ai.mMeshes[i];
 414                 const aiMesh &mesh = meshes[meshIdx].ai;
 415
 416                 for (int j = 0; j < mesh.mNumVertices; j++) {
 417                         glm::vec4 vPos = glm::vec4(aiVector3DToMat4(mesh.mVertices[j]), 1);
 418                         // Move from model space -> world space
 419                         vPos = parentTrans * aiMatrixToMat4(n.ai.mTransformation) * vPos;
 420                         float dist = glm::distance(glm::vec3(vPos),
 421                                                         glm::closestPointOnLine(glm::vec3(vPos), a, b));
 422                         if (dist < shortestDist) {
 423                                 closest = glm::vec3(vPos);
 424                                 shortestDist = dist;
 425                         }
 426                 }
 427         }
 428
 429         for (auto child: n.getChildren()) {
 430                 auto res = closestVertex(*child, a, b, parentTrans * aiMatrixToMat4(n.ai.mTransformation));
 431                 if (res.second < shortestDist) {
 432                         closest = res.first;
 433                         shortestDist = res.second;
 434                 }
 435         }
 436
 437         return { closest, shortestDist };
 438 }