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
