Generating natural-looking motion for computer animation

The automatic generation of motion for animation remains an unsolved problem in computer graphics. One approach to the problem is to combine physically accurate models with control systems. The user specifies high-level goals and the control system computes the forces and torques that the simulated muscles or motors should exert to cause the model to perform the desired task. In this paper we describe control systems for rigid-body models of humans performing four tasks: pumping a swing, riding a seesaw, juggling, and pedaling a unicycle. We designed the control systems with the goal of producing natural-looking motion, and we discuss the techniques that we used to achieve this goal.