Dynamic Analysis-Based Human Animation

Abstract

Dynamic analysis-based human animation is proposed and implemented. In this approach, the actual human movements are first analyzed to find out the mechanism behind them, then the knowledge obtained by the analysis is used to design new motions desired by animators. Here, the knowledge includes the dynamic parameters such as the forces and torques exerted on the joints, which is obtained through analyzing the actual movements of a human body. In this approach, animation proceeds in three steps:dynamics, constraints and inverse dynamics. In the first step ofdynamics, each body segment is distinguished and the motion of each segment is derived in the form of dynamics equations. The idea is to reduce the number of degrees of freedom and thus the amount of computations required, and to avoid the complexity of dealing with continuum mechanics. In the second step ofconstraints, the constraints involving both the articulation of the body and the range of the movement of each joint are checked and maintained. A segment which violates its constraints is moved by translations and rotations so that it becomes connected to its super segment or is bent into a natural posture. In the third step of inverse dynamics, the forces that produce the motion adjusted according to the two types of constraints are calculated by using dynamics equations, and the results that involve the motions and the forces are then presented to the user. As the result of animation, a walk on the moon, is also presented.