There are lots of things that can be pre-rendered for such animations. nVidia has an Ogre tech demo that uses precalculated ambient occlusion: An AO pass is prerendered in a regular renderer (like PRMan or Mental Ray) and written to a video texture. During the animation, the video texture is read and applied to the moving model. Similar things were done a while ago with "light maps", which is lighting baked to textures.