Facial Rigging
Blend shapes and joints for facial expressions
Also known as: Facial animation rig · FACS · ARKit blendshapes · Face blend shapes · Facial joints · Lip sync rig
Definition
Facial rigging is building the controls that let a character's face move and show expressions. The usual methods are blend shapes, which store each expression as a shape of the whole face, and joints, which move the lips, brows and eyes like a skeleton, and many rigs combine both. FACS, the Facial Action Coding System, is a standard catalog of facial muscle movements that artists use to plan shapes, and Apple's ARKit uses a set of about 52 blend shapes that many pipelines follow for face capture.
In production
Plan the expressions the game needs, from a few for a mobile character to a full set for a cinematic hero, and sculpt each shape on clean topology with enough loops around the eyes and mouth. Name shapes consistently so animation and capture tools can find them. Test with lines of speech and extreme expressions. Blend shapes are cheap in cost for faces, but their number and vertex counts add up.
