A Facial Repertoire for Avatars

Facial expressions are becoming more and more important in today’s computer systems with humanoid user interfaces. Avatars have become popular, however their facial communication is usually limited. This is partly due to the fact that many questions, especially on the dynamics of expressions, are still open. Moreover, the few commercial facial animation tools have limited facilities, and are not aimed at lightweight Web applications. In this article we discuss the empirical basis and a software tool to produce faces with emotional expressions and lip-sync. In order to elicit the characteristics of expressions on real human faces and to map them on synthetic, non-realistic ones, we analysed expressions on real and artist-drawn cartoon faces. We developed CharToon, a software tool that allows the construction of faces and to animate them from scratch or by re-using components of the facial feature and expression repertoire. CharToon faces can be animated real time. The list of applications includes 3D faces of avatars in a VRML environment.

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