Facial Animation - Computer Animation: Algorithms and Techniques - page 331

Contractile unit

Damper

Springs

FIGURE 10.19
Hill's model for the muscle.

Sad Happy

Disgust Anger

Fear Surprise

FIGURE 10.20
A basic set of facial expressions [ 30 ] .

(Image courtesy of Arun Somasundaram.)

10.3.4 Expressions
Facial expressions are a powerful means of communication and are the basis for most facial animation.
Any facial animation systemwill provide for a basic set of expressions. A commonly used set is: happy,
angry, sad, fear, disgust, and surprise ( Figure 10.20 , Color Plate 12).

10.3.5 Summary
A wide range of approaches can be used to model and animate the face. Which approach to use depends
greatly on how realistic the result is meant to be and what kind of control the animator is provided.
Results vary from cartoon faces to parameterized surface models to skull-muscle-skin simulations.
Realistic facial animation remains one of the interesting challenges in computer animation.