// render the loaded model glm::mat4 model = glm::mat4(1.0f); model = glm::translate(model, glm::vec3(0.0f, 0.0f, 0.0f)); // translate it down so it's at the center of the scene model = glm::scale(model, glm::vec3(1.0f, 1.0f, 1.0f)); // it's a bit too big for our scene, so scale it down ourShader.setMat4("model", model); ourModel.Draw(ourShader);
// glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.) // ------------------------------------------------------------------------------- glfwSwapBuffers(window); glfwPollEvents();
voidDraw(Shader &shader) { // bind appropriate textures unsignedint diffuseNr = 1; unsignedint specularNr = 1; unsignedint normalNr = 1; unsignedint heightNr = 1; for(unsignedint i = 0; i < textures.size(); i++) { glActiveTexture(GL_TEXTURE0 + i); // active proper texture unit before binding // retrieve texture number (the N in diffuse_textureN) string number; string name = textures[i].type; if(name == "texture_diffuse") number = std::to_string(diffuseNr++); elseif(name == "texture_specular") number = std::to_string(specularNr++); // transfer unsigned int to stream elseif(name == "texture_normal") number = std::to_string(normalNr++); // transfer unsigned int to stream elseif(name == "texture_height") number = std::to_string(heightNr++); // transfer unsigned int to stream
// now set the sampler to the correct texture unit glUniform1i(glGetUniformLocation(shader.ID, (name + number).c_str()), i); // and finally bind the texture glBindTexture(GL_TEXTURE_2D, textures[i].id); }
classModel { public: // model data vector<Texture> textures_loaded; // stores all the textures loaded so far, optimization to make sure textures aren't loaded more than once. vector<Mesh> meshes; string directory; bool gammaCorrection;
// constructor, expects a filepath to a 3D model. Model(stringconst &path, bool gamma = false) : gammaCorrection(gamma) { loadModel(path); }
// draws the model, and thus all its meshes voidDraw(Shader &shader) { for(unsignedint i = 0; i < meshes.size(); i++) meshes[i].Draw(shader); }
private: // loads a model with supported ASSIMP extensions from file and stores the resulting meshes in the meshes vector. voidloadModel(stringconst &path) { // read file via ASSIMP Assimp::Importer importer; const aiScene* scene = importer.ReadFile(path, aiProcess_Triangulate | aiProcess_GenSmoothNormals | aiProcess_FlipUVs | aiProcess_CalcTangentSpace); // check for errors if(!scene || scene->mFlags & AI_SCENE_FLAGS_INCOMPLETE || !scene->mRootNode) // if is Not Zero { cout << "ERROR::ASSIMP:: " << importer.GetErrorString() << endl; return; } // retrieve the directory path of the filepath directory = path.substr(0, path.find_last_of('/'));
// process ASSIMP's root node recursively processNode(scene->mRootNode, scene); }
// processes a node in a recursive fashion. Processes each individual mesh located at the node and repeats this process on its children nodes (if any). voidprocessNode(aiNode *node, const aiScene *scene) { // process each mesh located at the current node for(unsignedint i = 0; i < node->mNumMeshes; i++) { // the node object only contains indices to index the actual objects in the scene. // the scene contains all the data, node is just to keep stuff organized (like relations between nodes). aiMesh* mesh = scene->mMeshes[node->mMeshes[i]]; meshes.push_back(processMesh(mesh, scene)); } // after we've processed all of the meshes (if any) we then recursively process each of the children nodes for(unsignedint i = 0; i < node->mNumChildren; i++) { processNode(node->mChildren[i], scene); }
}
Mesh processMesh(aiMesh *mesh, const aiScene *scene) { // data to fill vector<Vertex> vertices; vector<unsignedint> indices; vector<Texture> textures;
// walk through each of the mesh's vertices for(unsignedint i = 0; i < mesh->mNumVertices; i++) { Vertex vertex; glm::vec3 vector; // we declare a placeholder vector since assimp uses its own vector class that doesn't directly convert to glm's vec3 class so we transfer the data to this placeholder glm::vec3 first. // positions vector.x = mesh->mVertices[i].x; vector.y = mesh->mVertices[i].y; vector.z = mesh->mVertices[i].z; vertex.Position = vector; // normals if (mesh->HasNormals()) { vector.x = mesh->mNormals[i].x; vector.y = mesh->mNormals[i].y; vector.z = mesh->mNormals[i].z; vertex.Normal = vector; } // texture coordinates if(mesh->mTextureCoords[0]) // does the mesh contain texture coordinates? { glm::vec2 vec; // a vertex can contain up to 8 different texture coordinates. We thus make the assumption that we won't // use models where a vertex can have multiple texture coordinates so we always take the first set (0). vec.x = mesh->mTextureCoords[0][i].x; vec.y = mesh->mTextureCoords[0][i].y; vertex.TexCoords = vec; // tangent vector.x = mesh->mTangents[i].x; vector.y = mesh->mTangents[i].y; vector.z = mesh->mTangents[i].z; vertex.Tangent = vector; // bitangent vector.x = mesh->mBitangents[i].x; vector.y = mesh->mBitangents[i].y; vector.z = mesh->mBitangents[i].z; vertex.Bitangent = vector; } else vertex.TexCoords = glm::vec2(0.0f, 0.0f);
vertices.push_back(vertex); } // now walk through each of the mesh's faces (a face is a mesh its triangle) and retrieve the corresponding vertex indices. for(unsignedint i = 0; i < mesh->mNumFaces; i++) { aiFace face = mesh->mFaces[i]; // retrieve all indices of the face and store them in the indices vector for(unsignedint j = 0; j < face.mNumIndices; j++) indices.push_back(face.mIndices[j]); } // process materials aiMaterial* material = scene->mMaterials[mesh->mMaterialIndex]; // we assume a convention for sampler names in the shaders. Each diffuse texture should be named // as 'texture_diffuseN' where N is a sequential number ranging from 1 to MAX_SAMPLER_NUMBER. // Same applies to other texture as the following list summarizes: // diffuse: texture_diffuseN // specular: texture_specularN // normal: texture_normalN
// return a mesh object created from the extracted mesh data return Mesh(vertices, indices, textures); }
// checks all material textures of a given type and loads the textures if they're not loaded yet. // the required info is returned as a Texture struct. vector<Texture> loadMaterialTextures(aiMaterial *mat, aiTextureType type, string typeName) { vector<Texture> textures; for(unsignedint i = 0; i < mat->GetTextureCount(type); i++) { aiString str; mat->GetTexture(type, i, &str); // check if texture was loaded before and if so, continue to next iteration: skip loading a new texture bool skip = false; for(unsignedint j = 0; j < textures_loaded.size(); j++) { if(std::strcmp(textures_loaded[j].path.data(), str.C_Str()) == 0) { textures.push_back(textures_loaded[j]); skip = true; // a texture with the same filepath has already been loaded, continue to next one. (optimization) break; } } if(!skip) { // if texture hasn't been loaded already, load it Texture texture; texture.id = TextureFromFile(str.C_Str(), this->directory); texture.type = typeName; texture.path = str.C_Str(); textures.push_back(texture); textures_loaded.push_back(texture); // store it as texture loaded for entire model, to ensure we won't unnecesery load duplicate textures. } } return textures; } };
