对于先进的几何形状，大多数应用程序将更喜欢加载前

代码说明：

For advanced geometry, most apps will prefer to load pre-authored meshes from a file. Fortunately, when using meshes, D3DX does most of the work for this, parsing a geometry file and creating vertx buffers for us. This tutorial shows how to use a D3DXMESH object, including loading it from a file and rendering it. One thing D3DX does not handle for us is the materials and textures for a mesh, so note that we have to handle those manually.