Phonemes, Visemes, Lip Syncing, and Facial Animation Theoretic

Shape of The Mouth

See the source image

Issues to Look Out For

  • Too weak mouth movement.
  • Or too strong.
  • Out of sync with the audio, in terms of timing.
  • Doesn’t fit the mood or emphasis that the audio has.
  • The dialogue/audio always comes before the animation.
  • Try to exaggerate the mouth shape on the rig character. Like with rotoscoping, if you follow a humans mouth too closely it may seem to weak. It should look better it slightly exaggerated (if that fits the style of animation you are going for e.g. the YouTube link below-cartoon style). You can add bigger mouth shapes when necessary to emphasise the character.
Like so. Do not emphasise the mouth expression all the time. Be selective and choose moments where added emphasis will enhance add character.
Reference for improving lip syncing animations.

Examples of Facial Animation

Good for reference…