keyframe + mouth replacement


I need to quickly get a rig done that I imagine is simple, but I’m unsure how to do it. Theres a character whose head moves back and forward in a loop, and I have that animated. I now need to track a mouth to that loop. The characters mouth flapping will not be in a loop, so it needs to be tracked separately. I imagine I could keyframe, and still have the mouth do its normal animation. Can anyone elaborate on how to achieve this?

I’ve had a similar problem… my solutions went something like this…

First possibility:
Start with two drawing layers – Main layer and Mouth layer
create your animated head bobbing loop on your Main layer but draw a simple mouth in there as your guide for the next stage…
now on your Mouth layer, draw in your lipsync frame by frame, using that mouth on the main layer as your guide.
last, you come back and delete that preliminary mouth from your main layer.
This is a quick and dirty way and doesn’t allow for easy editing - basically if you mess up, you gotta go back and fix several drawings… Don’t stress thoughm, because the head is moving, your mouth animation can actually be incredibly sloppy and still work fine.

Second possibility:
Start with 3 layers: Main, Head, Mouth
You’ll use a hierarchy - Main layer is parent, Head is its child and Mouth is Head’s child.
Do your head-bob loop on the Main layer.
Now draw a head on the Head layer and keyframe it along to your loop
Do your lipsync on the Mouth layer and then simply anchor it to the preferred spot on your head in your Head layer - it should now stay in the correct place in time to your loop
Benefit of this approach is the ability to reuse mouth substitutions and make corrections easy