Should my facial expression shape keys depend on facial bones?

Coding Python Support
1

I’d like to use shape keys for facial expressions and lip syncing in my next project and am wondering if they should rely on any facial bones. I’m used to animating the face with bones. I can see how using shape keys would eliminate the need for lip bones, but I’m not so sure about the jaw.

For example, if I want to create a pose for the face saying the “ay” syllable, the mouth is going to need to be open slightly. Should I do this by moving the jaw bone open and then scupting the lips into the right pose? Or should I not move the jaw bone at all and instead sculpt both the lips and jaw line? Should I perhaps not even have a jaw bone if I’m going to be using shape keys?

I have similar questions about the eyes. I’m going to need to at least have bones for the eyeballs, but I’m not sure if I should be using shape keys to augment facial bones or to replace them.

2

I think this depends on the way you are using it…
For example:

  • a “slighlty” animated face expression might be done with bones or shapekeys alone
  • a “fine graded” one might use a “base” animation via bones and “refined” via shapekeys
  • there might be even a double solution with some basic bones and fine tune bones

The more detailed version may also depend with what you are more familiar…
And this may also depend on the final result you are after… precision- and/or time-consuming–wise…