【Mesh Filter】
The Mesh Filter takes a mesh from your assets and passes it to the Mesh Renderer for rendering on the screen.
Mesh Filter决定使用哪一个Mesh。Mesh Filter只有一个参数，就是指定Mesh。
When importing mesh assets, Unity automatically creates a Skinned Mesh Renderer if the mesh is skinned, or a Mesh Filter along with a Mesh Renderer, if it is not.
【Mesh Render】
The Mesh Renderer takes the geometry from the Mesh Filter and renders it at the position defined by the object's Transform component.
Mesh Render 负责渲染 Mesh Filter 指定的 Mesh，在 Transform 的位置渲染这个Mesh。
Mesh Render参数主要指定是否产生和接受阴影，以及使用了Meterial。
Meshes imported from 3D packages can use multiple Materials. Each submesh will use one material from the materials list. If there are more materials assigned to the Mesh Renderer than there are submeshes in the mesh, the first submesh will be rendered with each of the remaining materials, one on top of the next. At a cost of performance, this will let you set up multi-pass rendering on that submesh. Fully opaque materials, however, will simply overwrite the previous layers, costing performance for no advantage.
如果有多个Meterial，并且Meterial数量多过Submesh的数量，则第一个Mesh会使用自己对应的meterial以及剩下的meterial。排最后的meterial会被前面的meterial覆盖或混合。
一个GameObejct如果拥有多个Material，则Unity会将多个Material转化为多个Pass。
