Ok, yeah, the setup you’re after is pretty much what I explained, but your bones that you choose for weighting is obviously the important part here. It’s not a complex setup. I’m going to try and just say here what should be weighted to what, and see if you get it working like that, and basically take it from there.
So, first thing is to make sure all the linking is correct. It’s pretty simple but needs to be a specific way since you need some anchor points for the blended bones to work from.
First, I’m going to call that one un-numbered bone in the upper middle lip, I’ll call that Bone 0. It’s also going to be used quite a bit.
-
So, for linking, link all bones, including Bone 0 to the head. But link Bone 2 to Bone 1. The way this will end up working is Bone 0 is the “head” anchor and Bone 2 is the “jaw” anchor and the rest of them needs basically a “static” parent, which is the head.
-
Bones 0 and 2 are now going to be your anchors, they’re not getting weighted, for every other bone you are going to set up the Position Constraint. So you go and add the Position List, Position Constraint and Position XYZ to Bones 3, 4 and 5 on both sides.
-
Now, for the weighting on all Bones, 3, 4 and 5, on both sides, you will add Bone 0 and 2 to the weight list.
-
On each bone now you can type in the desired weights. For example, Bone 3 will actually need no change, it will automatically be weighted 50/50. Even though it’ll say 100/100, that translates to a 50/50 weight between the two bones. But Bone 4 you want on 20% towards the jaw, so you would type the weight 20/80 with 20 on Bone 2 and 80 on Bone 0. Then of course Bone 5 will be 10/90 the same way. You may find you wanna tweak those weights and an easy way is to open the jaw and just tweak them and they will shift as you tweak and you can get the exact position you want.
What this will do though is move those bones into those weighted positions, so they won’t be where you placed them anymore, they will be in a new location, based on the weighting information. This is where you use the Position XYZ you added to the controller list, to just move them back to their original locations, based on the jaw being closed, the original pose. So they will still be weighted, but you can place them back correctly and when you then open the jaw, the weights will take care of the positioning. While animating you can also then add manual adjustments on top of the weighted positioning as well having that Position XYZ in the list.
Hope this helps more towards your actual goal than my other attempts… 