Real-time playback in animation systems

Abstract

A technique often employed in animated vector graphics involves the use of a real-time playback mechanism. This technique is an alternative when it is not possible to generate animation frames in real-time. Instead frames are compiled in advance at non-real-time rates, saved in secondary storage, and then played back at desired real-time rates. The basic design of such a playback mechanism will be considered, including discussions of synchronization, buffering, and blocking. Two special properties will be established for these systems: the conditions required to achieve real-time reversal in the direction of the playback sequence, and the existence of upstream/downstream effects, performance differences between directions in systems that are run "too fast."