Space‐Time Warp Curve for Synthesizing Multi‐character Motions

Abstract

This paper introduces a new motion‐synthesis technique for animating multiple characters. At a high level, we introduce a hub‐sub‐control‐point scheme that automatically generates many different spline curves from a user scribble. Then, each spline curve becomes a trajectory along which a 3D character moves. Based on the given curves, our algorithm synthesizes motions using a cyclic motion. In this process, space‐time warp curves, which are time‐warp curves, are embedded in the 3D environment to control the speed of the motions. Since the space‐time warp curve represents a trajectory over the time domain, it enables us to verify whether the trajectory causes any collisions between characters by simply checking whether two space‐time warp curves intersect. In addition, it is possible to edit space‐time warp curves at run time to change the speed of the characters. We use several experiments to demonstrate that the proposed algorithm can efficiently synthesize a group of character motions. Our method creates collision‐avoiding trajectories ten times faster than those created manually.

Keywords

• 3D motion synthesis
• 3D crowd animation