Limb coordination system for interactive computer animation of articulated characters with blended motion data

摘要

A method and apparatus for interactively controlling and coordinating the limb movements of computer-generated articulated. 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 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. Recorded motion data is combined with interactive control techniques to manipulate the animation of articulated figures. The methods enable computer animated characters to produce fully interactive goal-directed behaviors, while retaining qualitative characteristics of the original non-interactive motion data. Non-interactive motion capture and keyframe data, representing examples of desired character movements, are accommodated in the present animation system in three ways: 1) direct approach--non-interactive motion data used directly to specify desired body posture synergy goals as a function of time, 2) hybrid approach--non- interactive motion data and program control commands blended to specify elements of desired position, alignment and/or balance synergy goals as a function of time, and 3) template approach-- non-interactive motion data used to auto-tune adjustable parameters, enabling program control commands to generate fully interactive movements that qualitatively resemble the non-interactive motion data.