from my friend on skype:
"If you combine this with a vertex shader that quantizes bone position to limit the framerate of character animation, you could do some pretty sick things with IK"
I don't know jack all about this "Third Dimension" stuff but here you go
Yes, to achieve a better effect, "limited animation" should be used, with a small sumber of animation frames. This could also just be done directly in the 2d modelling application with keyframes spaced accordingly, and then with Unity slowing the animation down suficiently.