C++.OpenGL （15/64）Assimp（Open Asset Import Library）

Assimp（Open Asset Import Library）

3D模型加载核心流程

1. Assimp集成

安装与包含：

# Linux安装
sudo apt-get install libassimp-dev# Windows：下载预编译库
https://github.com/assimp/assimp/releases

CMake配置：

find_package(assimp REQUIRED)
target_link_libraries(YourProject assimp::assimp)

代码包含：

#include <assimp/Importer.hpp>
#include <assimp/scene.h>
#include <assimp/postprocess.h>

2. 模型加载基础

Assimp::Importer importer;
const aiScene* scene = importer.ReadFile("models/backpack.obj",aiProcess_Triangulate | aiProcess_FlipUVs |aiProcess_CalcTangentSpace |aiProcess_GenNormals
);if (!scene || scene->mFlags & AI_SCENE_FLAGS_INCOMPLETE || !scene->mRootNode) {std::cerr << "Assimp error: " << importer.GetErrorString() << std::endl;return;
}

常用处理标志：

标志	描述
`aiProcess_Triangulate`	将多边形转换为三角形
`aiProcess_FlipUVs`	翻转纹理坐标Y轴
`aiProcess_GenNormals`	自动生成法线
`aiProcess_CalcTangentSpace`	计算切线空间
`aiProcess_OptimizeMeshes`	合并网格减少绘制调用
`aiProcess_JoinIdenticalVertices`	合并重复顶点

3. 网格类设计

头文件 Mesh.h：

class Mesh {
public:// 网格数据std::vector<Vertex> vertices;std::vector<unsigned int> indices;std::vector<Texture> textures;Mesh(std::vector<Vertex> vertices, std::vector<unsigned int> indices, std::vector<Texture> textures);void Draw(Shader &shader);private:// 渲染状态unsigned int VAO, VBO, EBO;void setupMesh();
};struct Vertex {glm::vec3 Position;glm::vec3 Normal;glm::vec2 TexCoords;glm