jaw movement

[branaway]

One thing I really like to see is the jaw move with the mouth. Currently jaw does not move along with any mouth expression. Any way to animation the jaw?

[0b5vr]

There is a community-driven convention called PerfectSync and you might find it helpful:
https://hinzka.hatenablog.com/entry/2021/12/21/222635

Why do you want to move the jaw though?

[branaway]

Thanks for the reply. A smile without jaw movement is very unnatural. The sample model (./models/VRM1_Constraint_Twist_Sample.vrm) has turned out to be jaw bone-less, therefore nothing to manipulate.