Is this caused by MHX2 or MH?

[Aranuvir]

Ok, to be more precise: I was never able to pose the jaw-bone when the face-rig drivers were present. It is a different question whether to subsume the jaw-bone under the head-bones or the face-bones. IMHO it does not make sense subsuming it under the head-bones. So, from this point of view, it is a bug and the jaw-bone shouldn't be present when the face-layer is disabled.

[Fred Astair]

Ok, to be more precise: I was never able to pose the jaw-bone when the face-rig drivers were present. It is a different question whether to subsume the jaw-bone under the head-bones or the face-bones. IMHO it does not make sense subsuming it under the head-bones. So, from this point of view, it is a bug and the jaw-bone shouldn't be present when the face-layer is disabled.

It is not a matter of subsuming a particular bone into one or the another collection. You are talking about two completely different bones with different capabilities. The face bone that opens the jaw for expressions and/or manual adjustment cannot open the jaw wide enough to be realistic in some situations, (such as when you want your character to let out a rebel yell). The jaw bone included in the HEAD bone collection can do that, when it is working properly, and I have in the past used it to open the mouth wider AFTER choosing an expression that I liked. This possibility to combine both the expressions and the jaw pivot simultaneously has only recently disappeared. The fact that this very bone still works 66% (left and right and up and down, but just not the pivot function), indicates to me that the bone itself is not disabled, just the function to pivot it, which I'm guessing is an over sight in the code that Thomas will find and fix, as is probably the case with the eyes moving in the opposite direction when you try to point them.

I am writing this post so that Thomas becomes aware of the issue, not so that you or others can come up with theories about why its probably not worth fixing.

[ThomasL]

This cannot be fixed easily as things are designed today. The jaw bone is part of some expressions, so if expressions are enabled, the jaw is driven by rig properties and cannot be posed independently. One way to solve this would be to have two jaw bones: a parent driven by rig properties, and a child used for tweaking. It will take some work to implement that, though

[Fred Astair]

This cannot be fixed easily as things are designed today. The jaw bone is part of some expressions, so if expressions are enabled, the jaw is driven by rig properties and cannot be posed independently. One way to solve this would be to have two jaw bones: a parent driven by rig properties, and a child used for tweaking. It will take some work to implement that, though

It seems worthwhile doing to me. As it stands, we can only open the mouth part way and that is limiting from a realism point of view. When the expressions are not loaded and the jaw bone works as usual, the mouth can be opened throughout its entire range.

I still don't understand why the jaw bone can move sideways and up and down, but not rotate. How can that be if "the jaw is driven by rig properties and cannot be posed independently"? Shouldn't the jaw bone be completely disabled, if that is the case?

Also, visemes don't interfere with rotating the jaw bone. Implementing a viseme moves the jaw bone, and then you get to rotate the jaw more open, if you like.

Also, eyelids, which are grouped together with the jaw bone, can be moved side to side and up and down and ALSO, "rotated" when expressions are working. Since they are involved with expressions, why is it that they aren't partially disabled too? Why is it that the only function, out of all of these functions and "Head" bones, that doesn't work, is the rotation of the jaw bone? (Other than the eyes moving in the opposite direction to what they should)?

[ThomasL]

I still don't understand why the jaw bone can move sideways and up and down, but not rotate. How can that be if "the jaw is driven by rig properties and cannot be posed independently"? Shouldn't the jaw bone be completely disabled, if that is the case?

The expression buttons set the values of the Face Units properties, which in turn drive some channels of the bones. If you look at the jaw bone in the armature context, in pose mode, you see that the rotation channels are purple - they are driven. The location channels are not driven, though, so they can be posed as usual.

You should be able to open the jaw more by tweaking the JawDrop or JawDropStreched properties in the Face Units panel after an expression has been set. Or both, they are additive. This is really how the face bones are supposed to be used, I think. In this case I don't make the rules, mhx2 just exports what is already available inside MH.

[ThomasL]

I added an extra layer of bones to the face. Now you both use the expression and tweak all face bones on top of that. However, you should be aware that the visible face bones have new names: jaw-1 instead of jaw, etc. The old bones are still driven by rig properties but are now on a hidden layer.

This should be working both for exported mhx and rigify.

[Fred Astair]

I added an extra layer of bones to the face. Now you both use the expression and tweak all face bones on top of that. However, you should be aware that the visible face bones have new names: jaw-1 instead of jaw, etc. The old bones are still driven by rig properties but are now on a hidden layer.

This should be working both for exported mhx and rigify.

Wonderful !!!

Thank You

(And the eyes are working too....