Limb coordination system for interactive computer animation of articulated characters

Abstract

A method and apparatus for interactively controlling and coordinating the limb movements of computer-generated articulated characters with an arbitrary number of joints. On-line computational methods are used for animating limb movements of articulated characters by solving associated forward and inverse kinematics problems in real time subject to multiple goals and constraints. The methods provide computer animated characters with fully interactive goal-directed behaviors, such as bipedal walking, through simultaneous satisfaction of position, alignment, posture, balance, obstacle avoidance, and joint limitation constraints. Goal-based motion primitives, called synergies, coordinate sets of joint movements which separately attempt to satisfy each of the above constraints. The present methods adapt character movements on-line to accommodate uneven terrain, body modifications, or changes in the environment by automatically transforming and producing joint rotations relative to the instantaneous point of contact of the body with the world. Libraries of pre-configured goal-directed behaviors, such as reaching, sitting, walking, jumping, etc., can be constructed and used to animate a wide variety of characters.