Assimp是一种用于加载和处理3D模型的开源库。通常，该库可以正确地计算出模型的切向空间。然而，有时候Assimp会无声地失败，导致切向空间计算出错。这可能会导致纹理或光照方向出现问题，从而影响了渲染结果。

要解决这个问题，可以手动计算切向空间，而不是依赖Assimp自动计算。以下是一个使用glm库计算切向空间的示例代码：

// 循环处理所有模型数据 for(unsigned int i = 0; i < aiScene->mNumMeshes; i++) { aiMesh* mesh = aiScene->mMeshes[i];

// 计算切线和副切线
std::vector tangent(mesh->mNumVertices, glm::vec3(0.0f));
std::vector bitangent(mesh->mNumVertices, glm::vec3(0.0f));
for(unsigned int j = 0; j < mesh->mNumFaces; j++) {
    aiFace face = mesh->mFaces[j];
    for(unsigned int k = 0; k < 3; k++) {
        unsigned int vi1 = face.mIndices[k];
        unsigned int vi2 = face.mIndices[(k+1)%3];
        unsigned int vi3 = face.mIndices[(k+2)%3];

        glm::vec3 pos1(mesh->mVertices[vi1].x, mesh->mVertices[vi1].y, mesh->mVertices[vi1].z);
        glm::vec3 pos2(mesh->mVertices[vi2].x, mesh->mVertices[vi2].y, mesh->mVertices[vi2].z);
        glm::vec3 pos3(mesh->mVertices[vi3].x, mesh->mVertices[vi3].y, mesh->mVertices[vi3].z);

        glm::vec2 uv1(mesh->mTextureCoords[0][vi1