I should done demo recording for 3D car racing game, I need to record movement of all object and starting/stoping his subanimations but also generating of skid-marks on the way and smoke trails. The major problem is that recording and replaying may be done at different frame rates, so I don''t know how to interpolate and concatenate subanimation. (The time of starting/stoping can be between frames) Similar, should I record the positions of skid-marks or re-generate it in playback time? Is there some docs/papers about this on internet? Or source of game which use demo recording? Or other useful thing? Thanks