Synthesis and evaluation of linear motion transitions

TLDR

Motion transitions, which link animation sequences, are crucial for compelling virtual environments and games, and linear blending methods are favored for their efficiency, speed, and widespread use. The article develops methods to determine visually appealing motion transitions and blend lengths using linear blending. Two transition specification methods—center‑aligned and start‑end—are described, with optimal weights computed for a cost metric that balances transition points; the metric is evaluated for generalizability, appeal, and robustness via cross‑validation and user studies, and the techniques’ sensitivity to transition duration is assessed by measuring just‑noticeable differences. User studies confirm the effectiveness of the proposed methods for visually appealing motion transitions.

Abstract

This article develops methods for determining visually appealing motion transitions using linear blending. Motion transitions are segues between two sequences of animation, and are important components for generating compelling animation streams in virtual environments and computer games. Methods involving linear blending are studied because of their efficiency, computational speed, and widespread use. Two methods of transition specification are detailed, center-aligned and start-end transitions. First, we compute a set of optimal weights for an underlying cost metric used to determine the transition points. We then evaluate the optimally weighted cost metric for generalizability, appeal, and robustness through a cross-validation and user study. Next, we develop methods for computing visually appealing blend lengths for two broad categories of motion. We empirically evaluate these results through user studies. Finally, we assess the importance of these techniques by determining the minimum sensitivity of viewers to transition durations, the just noticeable difference, for both center-aligned and start-end specifications.