What are the uses of a blend shapes 3D model for VTubing?

Blend shapes in 3D models for VTubing create smooth, customizable facial expressions and subtle movements that make avatars lifelike and engaging during streams. They let VTubers naturally transition between emotions (e.g., smiling, frowning, raising an eyebrow) by blending base and target shapes, aligning the avatar’s reactions with their voice or actions—like lip-syncing to speech or adding eye blinks for realism. This human-like responsiveness helps viewers connect more deeply with the avatar. To boost expressiveness, VTubers can map common blend shapes (smile, blink, eyebrow raise) to live tracking inputs (voice or face capture) for intuitive control over the avatar’s emotions.