Animation of Human Walking: a Survey Franck Multon 1 , Laure France 2 , Marie-Paule Cani-Gascuel 3 , Gilles Debunne 3 1 IRISA, Campus Universitaire de Beaulieu, 35042 Rennes Cedex, France 2 BIP/INRIA, ZIRST- 655 ave. de l’Europe, 38330 Montbonnot Saint-Martin, France 3 iMAGIS-GRAVIR/IMAG BP 53, F-38041 Grenoble cedex 09, France Abstract: This paper surveys the set of techniques developed in Computer Graph- ics for animating human walking. We first focus on the evolution from purely kinematic “knowledge-based” methods to approaches that incorporate dynamics constraints, or use dynamic simulations to generate motion. We lastly review the recent advances on motion editing, that enable to control complex animations by interactively blending and tuning synthetic or captured motions. Keywords: computer animation, human walking, motion synthesis and control, kinematics, dynamics, motion capture. 1 Introduction Animating human walking is a crucial problem in Computer Graphics: Most synthetic scenes involve virtual humans, from special effects in cinema to virtual reality and video games. Synthesizing realistic human motion is a challenge: we are so used to see human locomotion that we will notice any artifact in the motion. Moreover, we may be unable to give any objective reason why a motion is unrealistic, while we may be really certain that it is so. These points increase the difficulty of the task. The study of walking motions has risen a lot of interest for a long time in other fields such as biomechanics and robotics. It appeared about fifteen years ago in Computer Graphic, with the first works on “knowledge-based” animation of human figures. The interest for this area never decreased since that time in the Computer Animation community. Finding one’s way through the number of different techniques what were proposed, and may refer to kinematics, dynamics, biomechanics, robotics and even signal processing is not easy. This survey provides a comparative study of previous works in the area of motion control in Computer Graphics, focussing on the solution each method brings to the animation of human walking. Rather than presenting a purely historical review, we classify previous works into three main streams, and try to put in evidence the intrinsic advantages and limitations of each approach: • Procedural methods based on knowledge-based kinematic animation are reviewed in Section 3. 1