Simulation System for Balance Control in Interactive Motion

摘要

Action games and animation movies require engaging character interaction with other characters and/or objects in dynamic environment, which lead to many possible responsive motions. However, it remains di cult to simulate diverse balanced interactive motion in dynamic system, which are widely determined by physics laws related to collision, balance control, bio-mechanics constraints, un-expected external forces such as a hit to any body part from the opponent character, following a user-required motion goal. A simulation system to achieve this research goal is provided in this documentation.;The input of this system is, given the current motion state such as a state after an hit from the opponent, a reasonable responsive motion goal required by the action director such as to give a counter-strike punch to the opponent head while decaying the energy of the hit to keep balance. The output is goal-directed balanced motion driven by joint torques in dynamic virtual environment.;The significant contribution is two proposed Lyapunov-Function-based constraints, which are used in the proposed optimization framework to find the optimal motion strategy which achieves the responsive motion goal while keeping balance. The first advantage of this system is to use the first Lyapunov-Function-based constraint to more quickly converge the optimization progress by eliminating massive candidate strategies unworkable to achieve the motion goal, rather than to test each candidate strategy by a traditional way based on dynamic forward simulation which require much more computation resources especially on time. The second advantage is to use the second Lyapunov-Function-based constraint to more quickly and more precisely judge the current balance state of motion and then employ it to predict the future balance state under control of the current motion controller.;In sum, our system would be unique to generate diverse balanced responsive fighting motion for action game and movies in a much more efficient manner. Namely the action designer are only required to provide an responsive motion goal (including objective action pose and timing information) like an action director in action movie, and then the system will automatically generate the controllable and balanced dynamics responsive fighting motion driven by joint torques, and motion capture data is not needed.