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，我得到了材质，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，但文件名字段显示空字符串和 fullPath 输出"*0"。 在mTexture中，它确实显示纹理文件扩展名".png"，但不显示纹理本身的文件名。感谢您的任何帮助。

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

如果有人对我如何解决问题感到好奇，如下所示。 在.mtl文件中，我必须添加map_Kd漫反射文件.png添加一个漫反射文件，以便assimp可以拾取纹理文件。

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

这应该正常工作。您能否提供 obj-model 及其相应的材料文件，并在此处生成新的问题报告：https://github.com/assimp/assimp/issues

然后，我们可以尝试调查您的示例中出了什么问题。