Interactive generation of falling motions

Abstract

Interactive generation of falling motions for virtual character with realistic responses to unexpected push, hit or collision with the environment is interesting work to many applications, such as computer games, film production, and virtual training environments. In this paper, we propose a new method to simulate protective behaviors in response to the ways a human may fall to the ground as well as incorporate the reactive motions into motion capture animation. It is based on simulated trajectory prediction and biomechanics inspired adjustment. According to the external perturbations, our system predicts a motion trajectory and uses it to select a desired transition-to sequence. At the same time, physically generated falling motions will fill in the gap between the two-motion capture sequences before and after the transition. Utilizing a parallel simulation, our method is able to predict a character's motion trajectory real-time under dynamics, which ensures that the character moves towards the target sequence and makes the character's behavior more life-like. Our controller is designed to generate physically plausible motion following an upcoming motion with adjustment from biomechanics rules, which is key to avoid an unconscious look for a character during the transition. Based on a relatively small motion database, our system is effective in generating various interactive falling behaviors. Copyright © 2006 John Wiley & Sons, Ltd.