AnimationClips mode can be used to bake a batch of AnimationClips directly without the need of setting up an AnimatorController. AnimationStates mode is useful for when you need to set up a more complex rig with layers and AvatarMasks in Mecanim. PlayableDirector mode bakes a Timeline. Realtime mode is for continuous baking of gameplay, ragdoll phsysics or PuppetMaster dynamics.