危机纳米服中的多个纹理 - 使用Assimp加载模型

我想在OpenGl/glsl中使用Assimp加载危机纳米服模型。该模型具有Assimp中节点树所述的几个网格。每个网格都与一个或多个纹理（扩散或镜面等）相关联。我如何在模型上呈现纹理，并且仍然使用单个拉动调用进行操作？

到目前为止，我已经能够加载模型没有纹理。这是我的做法：我使用节点树来找出模型中存在多少个网格，并使用结构阵列堆叠它们。这包含位置，正常，TexCoords，color_ambient，color_diffuse，color_pecular和Shininess的浮动值，vbo。由于网格是堆叠的，因此每个网格的索引阵列被相应地抵消。最终，通过单个抽奖电话，该模型成功地呈现了。这是整个代码，Relavent零件如下

struct Vertex
{
    glm::vec3 position;
    glm::vec3 normal;
    glm::vec2 texcoord;
    glm::vec3 colorambient;
    glm::vec3 colordiffuse;
    glm::vec3 colorspecular;
    float shininess;
};
// Creating a nodestack of all the meshes
void modelloader::NodeTreeTraversal(aiNode *node)
{
    if(node->mNumChildren==0)
        nodestack.push_back(node);
    else
        for(unsigned int i=0; i<node->mNumChildren; i++)
            this->NodeTreeTraversal(node->mChildren[i]);
}
// Look into assimp data structures for data and populate them into opengl's vbo's and ebo.
void modelloader::ProcessMeshes()
{
    // currently this method loads vertex positions, normals, textures;
    // also loads material info such as ambient, diffuse and specular colors with shininess as 16.0f
    Vertex vertex;
    unsigned int offset_faces=0;
    for(unsigned int i=0; i<this->nodestack.size(); i++)
    {
        aiNode *node = nodestack[i];
        for(unsigned int j=0; j<node->mNumMeshes; j++)
        {
            aiMesh *mesh = this->scene->mMeshes[node->mMeshes[j]];
            aiColor4D ambient;
            aiColor4D diffuse;
            aiColor4D specular;
            if(this->scene->HasMaterials()) {
                aiMaterial *mtl = scene->mMaterials[mesh->mMaterialIndex];
                aiGetMaterialColor(mtl, AI_MATKEY_COLOR_AMBIENT, &ambient);
                aiGetMaterialColor(mtl, AI_MATKEY_COLOR_DIFFUSE, &diffuse);
                aiGetMaterialColor(mtl, AI_MATKEY_COLOR_SPECULAR, &specular);
            }
            // load all mesh data
            for(unsigned int k=0; k<mesh->mNumVertices; k++)
            {
                // positions and normals
                vertex.position = glm::vec3(mesh->mVertices[k].x, mesh->mVertices[k].y, mesh->mVertices[k].z); // load positions
                vertex.normal = glm::vec3(mesh->mNormals[k].x, mesh->mNormals[k].y, mesh->mNormals[k].z); // load normals
                // load textures
                if(this->scene->HasTextures())
                    vertex.texcoord = glm::vec2(mesh->mTextureCoords[0][k].x, mesh->mTextureCoords[0][k].y);
                else vertex.texcoord = glm::vec2(0.0f, 0.0f);
                // load materials
                vertex.colorambient = glm::vec3(ambient.r, ambient.g, ambient.b);
                vertex.colordiffuse = glm::vec3(diffuse.r, diffuse.g, diffuse.b);
                vertex.colorspecular = glm::vec3(specular.r, specular.g, specular.b);
                vertex.shininess = 16.0f;
                // push back all the data for each vertex
                meshdata.push_back(vertex);
            }
            // create index data
            for(unsigned int l=0; l<mesh->mNumFaces; l++) {
                this->indices.push_back(mesh->mFaces[l].mIndices[0]+offset_faces);
                this->indices.push_back(mesh->mFaces[l].mIndices[1]+offset_faces);
                this->indices.push_back(mesh->mFaces[l].mIndices[2]+offset_faces);
            }
            offset_faces = offset_faces+mesh->mNumVertices;
        }
    }
    this->MeshData = &meshdata[0].position.x;
    this->MeshDataSize = meshdata.size() * 18 * sizeof(float);
    this->Indices = indices.data();
    this->IndicesSize = indices.size()*sizeof(unsigned int);
}
// draw call
void modelloader::RenderModel()
{
    glBindVertexArray(this->VAO);
    glDrawElements(GL_TRIANGLES, this->IndicesSize/sizeof(unsigned int), GL_UNSIGNED_INT, 0);
    glBindVertexArray(0);
}

这是输出图像。

现在，当加载纹理（为身体的每个部分分开图像文件）时，当我激活所有纹理atonce时，它将每个纹理文件拉伸到整个身体上。我该如何正确执行？

我的初步想法是：激活所有纹理文件。在VBO和片段着色器中添加一个称为" mesh_number"的属性，使用与" mesh_number"相对应的适当纹理。我不知道这是否会起作用。通常如何完成？您有任何代码样本吗？

当在此处完成的每个网格中应用绘制调用时，该问题就会解决。1）但是打电话不昂贵吗？我不应该一口气画整个网格吗？2）我是否应该创建一个拼贴到一个的身体部位的单个图像文件；很像精灵表？