Interactive control of big‐object manipulation animation

Abstract

We present a method for the interactive control of big-object manipulation animation. When a human character holds a big arbitrarily shaped object, it should use the whole upper body, including both arms and the torso in a limited range such that the holding postures can be physically as well as visually believable to users. In our method, we first sample various postures that satisfy our feasibility conditions: collision free and physically stable. The concept of the wrench space is used to evaluate the physical stability of holding postures. Then, we build a graph structure in which the nodes are the sampled postures and the links are collision-free motion interpolating between two-sampled postures. This manipulation motion graph allows us to use a general pathfinding method, such as Dijkstra's algorithm, to achieve real-time controllability. In our experiments, we build the manipulation motion graphs for differently shaped objects, and we demonstrate the usability of our method via several examples in which users interactively control the animation through the target positions or desired trajectories of the objects. Copyright © 2016 John Wiley & Sons, Ltd. KEYWORDS character animation; human body posture; physically based approach; big-object; interactive control Supporting information may be found in the online version of this article.