Methods for Measuring State Error for Control of Animated Human Figures

Abstract

Proportional plus Derivative (PD) control has been used widely to calculate the required forces to drive physically-based character animation. This approach requires the measurement of the state error or the difference between the measured and desired motion of the animated model. In this paper, three methods for measuring this state error are presented and compared. This includes a new method which focuses on minimising any accumulated linear transform error from rotational joints. All three methods were compared by measuring how precisely they were able to track a series of animation trajectories using a common setup. The new method presented here demonstrates improved tracking precision, particularly in cases where the kinematic dimensions of the animated model vary from those specified in the source animation.