+ // bones
+ std::vector<VertBones> vertBones(aiMesh->mNumVertices);
+
+ std::map<unsigned int, std::vector<std::pair<unsigned int, float>>> boneWeightMap;
+
+ for (unsigned int i = 0; i < aiMesh->mNumBones; i++) {
+ aiBone *aiBone = aiMesh->mBones[i];
+
+ boneMap[std::string(aiBone->mName.C_Str())] = std::pair(i + 1, aiBone);
+
+ for (int j = 0; j < aiBone->mNumWeights; j++) {
+ aiVertexWeight vw = aiBone->mWeights[j];
+
+ if (!boneWeightMap.count(vw.mVertexId))
+ boneWeightMap[vw.mVertexId] = std::vector<std::pair<unsigned int, float>>();
+ boneWeightMap[vw.mVertexId].push_back(std::pair(i + 1, vw.mWeight));
+ }
+ }
+
+ for (auto pair: boneWeightMap) {
+ unsigned int vertexId = pair.first;
+ for (int i = 0; i < pair.second.size() && i < 4; i++) {
+ unsigned int boneId = pair.second[i].first;
+ float weight = pair.second[i].second;
+ vertBones[vertexId].ids[i] = boneId;
+ vertBones[vertexId].weights[i] = weight;
+ }
+ }
+
+ glBindBuffer(GL_ARRAY_BUFFER, boneVbo);
+ glBufferData(GL_ARRAY_BUFFER, sizeof(VertBones) * vertBones.size(), &vertBones[0], GL_STATIC_DRAW);
+
+ GLuint boneIdLoc = glGetAttribLocation(progId, "boneIds");
+ glEnableVertexAttribArray(boneIdLoc);
+ glVertexAttribIPointer(boneIdLoc, 4, GL_INT, sizeof(VertBones), 0);
+
+ GLuint boneWeightLoc = glGetAttribLocation(progId, "boneWeights");
+ glEnableVertexAttribArray(boneWeightLoc);
+ glVertexAttribPointer(boneWeightLoc, 4, GL_FLOAT, GL_FALSE, sizeof(VertBones), (const GLvoid *)sizeof(VertBones::ids));
+}
+
+void Model::Mesh::updatePosBuffer() const {
+ GLuint posLoc = glGetAttribLocation(progId, "pos");
+ GLuint posVbo = vbos[0];
+ glBindBuffer(GL_ARRAY_BUFFER, posVbo);
+ glBufferData(GL_ARRAY_BUFFER, ai.mNumVertices * sizeof(aiVector3D), ai.mVertices, GL_STATIC_DRAW);
+ glEnableVertexAttribArray(posLoc);
+ glVertexAttribPointer(posLoc, 3, GL_FLOAT, GL_FALSE, 0, 0);
+}
+
+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) {
+ for (int i = 0; i < node.mNumMeshes; i++) {
+ meshIndices.push_back(node.mMeshes[i]);
+ }
+ for (int i = 0; i < node.mNumChildren; i++) {
+ aiNode *child = node.mChildren[i];
+ children.push_back(new Node(*child, progId, am, allBones, this));
+ }
+}
+
+glm::mat4 lerpPosition(const aiNodeAnim *anim, const float tick) {
+ if (anim->mNumPositionKeys == 0) return glm::mat4(1.f);
+
+ int yIndex = -1;
+ for (int i = 0; i < anim->mNumPositionKeys; i++) {
+ aiVectorKey vk = anim->mPositionKeys[i];
+ if (vk.mTime > tick) {
+ yIndex = i;
+ break;
+ }
+ }
+ aiVector3D lerpPos;
+ if (yIndex == 0) {
+ lerpPos = anim->mPositionKeys[0].mValue;
+ } else if (yIndex == -1) {
+ lerpPos = anim->mPositionKeys[anim->mNumPositionKeys - 1].mValue;
+ } else {
+ auto X = anim->mPositionKeys[yIndex - 1];
+ auto Y = anim->mPositionKeys[yIndex];
+
+ lerpPos = (X.mValue * (float)(Y.mTime - tick) + Y.mValue * (float)(tick - X.mTime)) / (float)(Y.mTime - X.mTime);
+ }
+ aiMatrix4x4 result;
+ aiMatrix4x4::Translation(lerpPos, result);
+ return aiMatrixToMat4(result);
+}
+
+glm::mat4 lerpRotation(const aiNodeAnim *anim, const float tick) {
+ int yIndex = -1;
+ for (int i = 0; i < anim->mNumRotationKeys; i++) {
+ aiQuatKey vk = anim->mRotationKeys[i];
+ if (vk.mTime > tick) {
+ yIndex = i;
+ break;
+ }
+ }
+
+ aiQuaternion result;
+ if (yIndex < 1) {
+ result = anim->mRotationKeys[0].mValue;
+ } else if (yIndex == -1) {
+ result = anim->mRotationKeys[anim->mNumRotationKeys - 1].mValue;
+ } else {
+
+ auto X = anim->mRotationKeys[yIndex - 1];
+ auto Y = anim->mRotationKeys[yIndex];
+
+ float mix = (tick - X.mTime) / (Y.mTime - X.mTime);
+
+ aiQuaternion::Interpolate(result, X.mValue, Y.mValue, mix);
+
+ }
+ return aiMatrixToMat4(aiMatrix4x4(result.GetMatrix()));
+}
+
+glm::mat4 lerpScaling(const aiNodeAnim *anim, const float tick) {
+ int yIndex = -1;
+ for (int i = 0; i < anim->mNumScalingKeys; i++) {
+ aiVectorKey vk = anim->mScalingKeys[i];
+ if (vk.mTime > tick) {
+ yIndex = i;
+ break;
+ }
+ }
+
+ aiVector3D lerpPos;
+ if (yIndex < 1) {
+ lerpPos = anim->mScalingKeys[0].mValue;
+ } else {
+ auto X = anim->mScalingKeys[yIndex - 1];
+ auto Y = anim->mScalingKeys[yIndex];
+
+ lerpPos = (X.mValue * (float)(Y.mTime - tick) + Y.mValue * (float)(tick - X.mTime)) / (float)(Y.mTime - X.mTime);
+ }
+ aiMatrix4x4 result;
+ aiMatrix4x4::Scaling(lerpPos, result);
+ return aiMatrixToMat4(result);
+}
+
+glm::mat4 Model::Node::totalTrans(const glm::mat4 parentTrans, const float tick) const {
+ glm::mat4 aiTrans = aiMatrixToMat4(ai.mTransformation);
+ if (animMap->count(std::string(ai.mName.C_Str()))) {
+ for (const Animation anim: animMap->at(std::string(ai.mName.C_Str()))) {
+ // animations are *absolute*
+ // they replace aiNode.mTransformation!!
+ aiTrans = glm::mat4(1);
+ float t = fmod(tick, anim.duration);
+ for (const aiNodeAnim *nodeAnim: anim.nodeAnims) {
+ aiTrans *= lerpPosition(nodeAnim, t);
+ aiTrans *= lerpRotation(nodeAnim, t);
+ aiTrans *= lerpScaling(nodeAnim, t);
+ }
+ }
+ }
+
+ glm::mat4 m = parentTrans * aiTrans * transform;
+ return m;
+}
+
+const Model::Node &Model::Node::getRoot() const {
+ const Model::Node *rootPtr = this;
+ while (rootPtr->parent != nullptr)
+ rootPtr = rootPtr->parent;
+ const Model::Node &root = *rootPtr;
+ return root;
+}
+
+void Model::Node::draw( const std::vector<Mesh> &meshes,
+ const std::vector<Material> &materials,
+ const Skybox skybox,
+ const float tick,
+ const BoneTransforms &boneTransforms,
+ glm::mat4 parentTrans = glm::mat4(1)) const {
+
+ GLuint modelLoc = glGetUniformLocation(progId, "model");
+ glm::mat4 m = totalTrans(parentTrans, tick);
+
+#ifdef DEBUG_NODES
+ if (isBone)
+ drawDebugNode(m, {0, 0.5, 1, 1});
+ else
+ drawDebugNode(m);
+#endif
+
+ for (unsigned int i: meshIndices) {
+ const Mesh &mesh = meshes[i];
+ glBindVertexArray(mesh.vao);
+
+ // bones
+ std::vector<glm::mat4> idBones(17, glm::mat4(1.f));
+ glUniformMatrix4fv(glGetUniformLocation(progId, "bones"), 17, GL_FALSE, glm::value_ptr(idBones[0]));
+
+ // bonemap: map from bone nodes to bone ids and aiBones
+ for (auto pair: mesh.boneMap) {
+
+ std::string boneName = pair.first;
+
+ unsigned int boneId = pair.second.first;
+ aiBone *bone = pair.second.second;
+ // This is actually an inverse-bind matrix
+ // i.e. transforms bone space -> mesh space
+ // so no need to inverse again!
+ // https://github.com/assimp/assimp/pull/1803/files
+ glm::mat4 boneOffset = aiMatrixToMat4(bone->mOffsetMatrix);
+
+ if (!boneTransforms.count(boneName)) abort();
+ glm::mat4 boneTrans = boneTransforms.at(boneName);
+
+ boneTrans = boneTrans * boneOffset;
+
+ std::string boneLocStr = "bones[" + std::to_string(boneId) + "]";
+ GLuint boneLoc = glGetUniformLocation(progId, boneLocStr.c_str());
+ glUniformMatrix4fv(boneLoc, 1, GL_FALSE, glm::value_ptr(boneTrans));