A shape is the position of one or more of the facial features on a head model. Every facial expression is created with a combination of shapes, with the facial features (such as the eyes, nose, mouth) each positioned in a particular way. By creating different combinations of these shapes, you can create any kind of expression on a head model.
You cannot create facial animation within MotionBuilder unless you have a head model with shapes or cluster shapes.
Shapes can also be referred to as gizmos or morph targets. Most often, face shapes change the position of the model’s mouth, eyebrows, eyes, cheeks, or nostrils. The type and number of shapes you create depends on your project.
For example, you can blend the “Brow Down” shapes with the “Mouth Corner Down” shapes to create an angry facial expression on the model, as shown in the following figure.
A. Brow Down shapes B. Mouth Corner Down shapes C. Resulting angry expression
