How do I create shape keys for facial expressions?
Setting Up Shape Keys
Select your character's face mesh and go to the Object Data Properties tab. Under Shape Keys, click the + button to add a Basis key. This stores the neutral shape.
Then click the + again to add a new key, name it (e.g., 'Smile'), and enter Edit Mode. Move vertices to create the smile. The Basis remains unchanged, and the new key stores the difference.
- Add Basis first to store neutral pose
- Each new key is a copy of the Basis
- Edit vertices in Edit Mode to sculpt expression
- Use Proportional Editing for smooth deformations
Creating Common Expressions
For a smile, pull the corners of the mouth up and out. For a blink, move the upper eyelid down to meet the lower. For anger, lower the brows and tighten the mouth. Each expression gets its own shape key.
You can also create corrective shapes for combinations, like a smile with raised brows. Use the Shape Key editor to mix values and see results in real time.
- Smile: raise mouth corners
- Blink: close eyelids
- Anger: furrow brows, press lips
- Surprise: open mouth, raise brows
- Use drivers to link shapes to controls
Animating and Combining Shape Keys
To animate, go to the Shape Keys panel and set keyframes on the Value sliders at different frames. You can also use drivers to control shape keys with custom properties or bones.
For complex expressions, combine multiple shape keys by adjusting their values. Use the NLA editor or drivers to blend them smoothly. Remember that shape keys are additive, so order can matter.
- Keyframe the Value sliders for animation
- Use drivers for bone-based control
- Blend multiple keys for nuanced expressions
- Check for intersections or artifacts
Common mistakes
- Editing the Basis after creating other keys, which shifts all expressions.
- Creating too many shape keys without organization, making them hard to manage.
- Forgetting to set keyframes on the Value sliders, so expressions don't animate.