I completely understand. <G>

I got one solution for the angle that didn't involve much calculation at all. Since the cylinder is rolling on it's x axis, the roll factor modulo 360 gives me the current roll angle. If I track the entities distance from the 0 "meridian", I know the angle needed for the entity. It's all frame of reference after all.

I'll still planning to investigate the straight vector calculation. I'll need to settle on one method or the other for a more general centrifugal movement scheme. But the calculated vectors may be necessary if I try to model something like a baseball game under centrifugal conditions.

One thing that comes to mind is any entity injected into the rotating cylinder is going to be affected by the airflow of the atmosphere around it. as it drifts further from the 0 axis there will be more and more of a "push" from the spinning gas inside the cylinder that will add to the objects own angle of momentum. Until it splatters into the wall anyway.

I'm now playing with the vector math and dusting off old math skills that I haven't used in ages. I'm trying to stick with c_move and the latest entity techniques as much as possible. Does anyone know where I can find a little more documentation on c_move and it's relatives?