Howdy,
I don’t think my client wants me to show the full character, so this is just his sexy lips.
I saw a rigging demo reel on cgtalk and loved the way he made the lips stay sealed even when the jaw is open, so with some experimentation, I was able to do it in Lightwave. I seal the lips simply by moving the controllers toward the center of his mouth. You can see it in action in the attached animation.
Awesome…would love to know more about the setup…looks like you have massive control!
Thanks Proton…
What I should really do is make a tutorial video on how I did it… That would be the best way… But since I don’t have that kind of time right now… I’ll say this:
The lips area was seperated out into a different weightmap. TrueArts’ “Show Weights” is a big help, and CombineWeightMap is another plugin that was invaluable.
Then the extracted lip weightmap was split up into 3 vertical blended areas using Combine WeightMaps in multiply mode.
So then I made six bones for the lips, one for each weightmap. And the slider nulls were used as controllers for expressions in the graph editor.
I learned about sub-expressions… didn’t know I could do that.
So I made a sub-expression to get the result of 50% of the jaw bone’s rotation… let’s call it “A”
Then the main expression was like this:
Is the slider moving toward the mouth center?
if yes: Clamp MapRange to “A”
if no: Clamp MapRage to that bone’s pulled-back (sneer) rotation amount.
Did that make any sense?
Edit: next time I do this, I will use 4 lip regions / bones instead of 3… It would yeild just a bit more flexibility for making various shapes… maybe 5 if I feel nutty. 
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