I'm animating a marble, with an image of the earth on it, rolling into other marbles using dynamics animation. When the marble hits the others it stops, as expected, but I want to use key animation at this point to make it revolve on its axis. I've set it up to switch from dynamics to key animation in the channel editor, but when it transitions, the "earth" marble snaps into a different rotation position, and then starts spinning. I've tried copying the rotation properties from the last frame of the dynamic animation to the first frame of the key animation, but this doesn't seem to work, i think, because the dynamic animation is "free form" and not always the same. Is there a way to make a smooth transition? Hope this is clear... thanks
If all you want to do is make the marble spin after the collision, and if the collision happens at a certain frame reliably (i.e. not different every time you run the simulation), you might be able to get away with just using some spin impulse.
'Impulse' and 'spin impulse' are properties every active rigid body have; they function like little rocket engines attached to the object. Turn on the impulse and the object begins to accelerate. You can keyframe impulse on and off and at different levels over time.
So in your case, you might key some high Spin Impulse Y (or whichever axis is appropriate) for the frame that the collision happens, then keyframe that impulse back to zero a frame or two later. This should start your marble spinning without needing to muck around going back and forth between dynamic and keyframe animation.