Assimp -如何使用任何文件格式导入带有纹理的网格？

Question

当我导入网格时，我得到了素材，但无法访问纹理的文件名。.mtl文件显式显示纹理的文件名。在代码中，它显示纹理计数为1，但文件名字段显示一个空字符串，fullPath输出"*0“。在mTexture中，它确实显示了纹理文件扩展名".png“，但没有显示纹理本身的文件名。谢谢你的帮助。

    if (scene->HasMaterials())
    {
        for (unsigned int i = 0; i < scene->mNumMaterials; ++i)
        {
            aiMaterial* material = scene->mMaterials[i];
            aiString name;
            material->Get(AI_MATKEY_NAME, name);
            aiReturn texFound = scene->mMaterials[i]->GetTexture(aiTextureType_DIFFUSE, i, &name);

            if (material->GetTextureCount(aiTextureType_DIFFUSE) > 0)
            {
                aiString path;
                if (material->GetTexture(aiTextureType_DIFFUSE, 0, &path, NULL, NULL, NULL, NULL, NULL) == AI_SUCCESS)
                {
                    std::string fullPath = path.data;


                }
            }
        }
    }

Answer 1

如果有人对我是如何解决我的问题感到好奇的话，请看下面。在.mtl文件中，我必须添加map_Kd diffusefile.png来添加一个漫射文件，这样assimp就可以获取纹理文件。

        if (scene->HasMaterials())//True when number of materials is greater than 0
        {
            for (unsigned int m = 0; m < scene->mNumMaterials; ++m)
            {
                aiMaterial* material = scene->mMaterials[m];//Get the current material
                aiString materialName;//The name of the material found in mesh file
                aiReturn ret;//Code which says whether loading something has been successful of not

                ret = material->Get(AI_MATKEY_NAME, materialName);//Get the material name (pass by reference)
                if (ret != AI_SUCCESS) materialName = "";//Failed to find material name so makes var empty

                //Diffuse maps
                int numTextures = material->GetTextureCount(aiTextureType_DIFFUSE);//Amount of diffuse textures
                aiString textureName;//Filename of the texture using the aiString assimp structure

                if (numTextures > 0)
                {
                    //Get the file name of the texture by passing the variable by reference again
                    //Second param is 0, which is the first diffuse texture
                    //There can be more diffuse textures but for now we are only interested in the first one
                    ret = material->Get(AI_MATKEY_TEXTURE(aiTextureType_DIFFUSE, 0), textureName);

                    std::string textureType = "diff_";
                    std::string textureFileName = textureType + textureName.data;//The actual name of the texture file
                }
            }

Answer 2

这将正常工作。请您提供obj-模型及其相应的材料文件，并在这里生成一个新的问题报告：https://github.com/assimp/assimp/issues。

然后我们可以试着研究一下你的例子中的问题。