I'm thinking about a ODE based physics system, and a skeletal animation system, the problem is that form the way i look at it I will have to recalculate the bone positions every few frames, and there will be no room for keyframes. entities will have 'musscles' which apply force to ODE joints, as the joints move the meshes are animated coorespondingly. BUT theres the problem, there won't be a very acurate way to predict where the bones will be so ... i'll just need a completely arbitray position for each bone at any given time. I know i can just grind my teeth together and not recalculate it at each frame, but still, i'll be rebuilding a bunch of quaterions and all of the verticies every step ... am i missing something?