Anticipation effect generation for character animation

According to the principles of traditional 2D animation techniques, anticipation makes an animation convincing and expressive. In this paper, we present a method to generate anticipation effects for an existing animation. The proposed method is based on the visual characteristics of anticipation, that is, "Before we go one way, first we go the other way [1]." We first analyze the rotation of each joint and the movement of the center of mass during a given action, where the anticipation effects are added. Reversing the directions of rotation and translation, we can obtain an initially guessed anticipatory pose. By means of a nonlinear optimization technique, we can obtain a consequent anticipatory pose to place the center of mass at a proper location. Finally, we can generate the anticipation effects by compositing the anticipatory pose with a given action, while considering the continuity at junction and preserving the high frequency components of the given action. Experimental results show that the proposed method can produce the anticipatory pose successfully and quickly, and generate convincing and expressive anticipation effects.