我正在关注LearnOpenGL网站上有关导入模型的教程。当我使用本教程中的模型时，一切正常，但是当我尝试绘制下载的其他模型时，它们绘制时没有纹理。谁能帮我解决这个问题？
我已经尝试过在obj文件的同一目录中更改纹理的位置，但没有任何更改。
void loadModel(string path){
// Read file via ASSIMP
Assimp::Importer importer;
const aiScene *scene = importer.ReadFile(path, aiProcess_Triangulate | aiProcess_FlipUVs);
// 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
this->directory = path.substr(0, path.find_last_of('/'));
// Process ASSIMP's root node recursively
this->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).
void processNode(aiNode* node, const aiScene* scene)
{
// Process each mesh located at the current node
for (GLuint 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]];
this->meshes.push_back(this->processMesh(mesh, scene));
}
// After we've processed all of the meshes (if any) we then recursively process each of the children nodes
for (GLuint i = 0; i < node->mNumChildren; i++)
{
this->processNode(node->mChildren[i], scene);
}
}
Mesh processMesh(aiMesh *mesh, const aiScene *scene)
{
// Data to fill
vector<Vertex> vertices;
vector<GLuint> indices;
vector<Texture> textures;
// Walk through each of the mesh's vertices
for (GLuint 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
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;
}
else
{
vertex.TexCoords = glm::vec2(0.0f, 0.0f);
}
vertices.push_back(vertex);
}
// Now wak through each of the mesh's faces (a face is a mesh its triangle) and retrieve the corresponding vertex indices.
for (GLuint 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 (GLuint j = 0; j < face.mNumIndices; j++)
{
indices.push_back(face.mIndices[j]);
}
}
// Process materials
if (mesh->mMaterialIndex >= 0)
{
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
// 1. Diffuse maps
vector<Texture> diffuseMaps = this->loadMaterialTextures(material, aiTextureType_DIFFUSE, "texture_diffuse");
textures.insert(textures.end(), diffuseMaps.begin(), diffuseMaps.end());
// 2. Specular maps
vector<Texture> specularMaps = this->loadMaterialTextures(material, aiTextureType_SPECULAR, "texture_specular");
textures.insert(textures.end(), specularMaps.begin(), specularMaps.end());
}
// 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 (GLuint 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
GLboolean skip = false;
for (GLuint j = 0; j < textures_loaded.size(); j++)
{
if (textures_loaded[j].path == str)
{
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;
textures.push_back(texture);
this->textures_loaded.push_back(texture); // Store it as texture loaded for entire model, to ensure we won't unnecesery load duplicate textures.
}
}
return textures;
}
};