Temporal anti-aliasing in computer generated animation

The desirability of incorporating temporal anti-aliasing, or motion blur, into computer generated animation is discussed and two algorithms for achieving this effect are described. The first approximates continuous object movement and determines intervals during which each object covers each pixel. Hidden surface removal is then performed, allowing the calculation of visible object intensity functions and subsequent filtering. The second form of algorithm detailed involves supersampling the moving image and then filtering the resulting intensity function to “multiply-expose” each output picture. The effects of filter types and the relationship of the algorithms to forms of spatial anti-aliasing are discussed.