Introduction

The face is the most complex part of the human body to set up. We spend our entire lives looking at human faces, and we're pretty good at detecting the subtlest changes and what they mean emotionally. It's a tough job trying to replicate this amount of complexity in CG: from the carefully built mesh topology to the detailed shading, texturing, and—of course—the animation controllers and movements.

The more you try to build a realistic human face in CG, the more details you have to add in order to avoid the uncanny valley effect. This terms refers to a hypothesis in the field of robotics which holds that the human observers tend to be repulsed by something that looks and moves barely like a human being: if it's not exactly like a human nor a clear abstraction of it (like a cartoon character), the observers notice that there's something "wrong" or "strange" to the character—often referred to as "zombie like".

There are books dedicated to the subject of facial rigging, and it wouldn...