PIMT: Physics-Based Interactive Motion Transition for Hybrid Character Animation

Yanbin Deng, Zheng Li, Ning Xie, Wei Zhang

Abstract: Motion transitions, which serve as bridges between two sequences of character animation, play a crucial role in creating long variable animation for real-time 3D interactive applications. In this paper, we present a framework to produce hybrid character animation, which combines motion capture animation and physical simulation animation that seamlessly connects the front and back motion clips. In contrast to previous works using interpolation for transition, our physics-based approach inherently ensures physical validity, and both the transition moment of the source motion clip and the horizontal rotation of the target motion clip can be specified arbitrarily within a certain range, which achieves high responsiveness and wide latitude for user control. The control policy of character can be trained automatically using only the motion capture data that requires transition, and is enhanced by our proposed Self-Behavior Cloning (SBC), an approach to improve the unsupervised reinforcement learning of motion transition. We show that our framework can accomplish the interactive transition tasks from a fully-connected state machine constructed from nine motion clips with high accuracy and naturalness.

Primary Subject Area: [Experience] Interactions and Quality of Experience

Secondary Subject Area: [Experience] Art and Culture, [Generation] Generative Multimedia

Relevance To Conference: The framework proposed in the paper combines two forms of character animation, motion capture animation controlled by joint position sequences and physical simulation animation controlled by joint motor torques (generated by the model), allowing real-time animation systems organized through state machine to generate corresponding transition animation between motion capture animations based on the control data input by the user (including the selected next motion, input time, and rotation angle).

Submission Number: 4868