In the context of facial animation and expression, particularly for virtual reality headsets like the Meta Quest Pro, "blendShapes" are a way to define and animate facial expressions by blending different facial geometry states. Common blendShapes for mouth animation typically include:
1. **Mouth Open** - Wide-open mouth.
2. **Mouth Close** - Completely closed mouth.
3. **Smile** - Corners of the mouth pulled upwards.
4. **Frown** - Corners of


