The motion of any physical entity is governed at the lowest level by the laws of physics. The use of physics is not new to computer graphics. It was introduced as ``physics-based modeling'' about a decade ago [Armstrong and Green1985, Wilhelms1987, Terzopoulos et al.1987] and has spawned a large body of advanced graphics modeling and animation research. Using physics-based models for graphics not only ensures physical realism of the resulting motion, it also allows subtle yet visually important motions to be animated automatically. Consider, for example, the realistic animation of a stampeding elephant. It would be a heroic chore to try to apply manual keyframing or other purely kinematic methods to animate the rippling flesh, the flapping ears, or the swinging trunk and tail. Physics-based modeling is capable of producing such motions automatically. More details about physics-based modeling and related previous work can be found in Chapter .
|Xiaoyuan Tu||January 1996|