The Essentials of Lip Sync
People overcomplicate things. It’s easy to assume that anything that looks good must also
be complex. In the world of 3D animation, where programs are packed with mile after
mile of options, tools, and dialog boxes, over-complication can
be an especially easy trap
to fall into. Not using every feature available to you is a good start in refining any technique
in 3D, and not always using the recommended tools is when you’re really advancing and
thinking outside the box. Many programs have controls and systems geared for facial ani-
mation, but you can usually find better tools for the job in their arsenals.
If you’ve ever tried lip sync in CGI, it has probably been frustrating, complicated, diffi-
cult, and unrewarding. In the end, most people are just glad to
see it get done and regret
deciding to involve sync in their project. We’re starting to see some amazing results come
from facial motion capture techniques, but that is outside of the cost range for most of
you out there reading this. Automated techniques are on the rise too, but so far, they
aren’t keeping up with a good artist or capture technique.
Don’t despair. I will get you set up for the sync part of things quickly and painlessly
so you can spend your time on performance (the fun stuff!). If your bag is automation,
there’s still a lot of information in here you can take so you can bump the quality up a
couple of notches on that, too.
When
teased apart properly, the lip sync portion of facial animation is the easiest to
understand because it’s the simplest. You see, people’s mouths don’t do
that much during
speech. Things like smiles and frowns and all sorts of neat gooey faces are cool, and we’ll
get to them later, but for now we’re just talking sync. Plain old speech. Deadpan and emo-
tionless and, well,
boring, is where our base will be. Now, you’re probably thinking, “Hey!
My face can do all sorts of stuff! I don’t want to do boring animation!” You’re right, your
face
can do all sorts of things, and who really wants to do boring animation? For the
basics, however, we’re not going to complicate it yet—that’ll come later.
In a very short
while, in Part II, we’ll build a model of a mouth that can do almost anything your mouth
can do, without needing hundreds or even thousands of blend shapes (believe it or not,
that’s how they do it in the movies!), but before we go and do that hands-on work, you’ll
need the stuff from this chapter in your head; let’s make sure you know the concepts
before we try to use any of them.
When dealing with the bare-bones essentials of lip sync and studying people, we’ve
whittled it down to just two basic motions. The mouth goes Open/Close, and it goes
Wide/Narrow; all of these are illustrated in Figure 1.1.
That’s really,
at its core, all that speech entails. If we were lip-syncing a character with
a plain circle for a mouth (and we will in just a minute), the shapes in Figure 1.2 would be
all the keys we would need to create the
illusion of speech—and that’s all we need to do. A
CG character need not actually speak; that’s some kind of Frankenstein experiment. All we
need to do is create the
illusion.
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chapter 1: Learning the Basics of Lip Sync
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Your reaction to this very short list of two motions might be, “What
about poses like F
where I bite my lip, or L where I roll up my tongue?”
Not answering that kind of question is
precisely the point of these early chapters. We ignore those unique and complicated shapes,
strip the process down to what is absolutely necessary to be understood visually, and then
build it back up from a solid base. If these two controls—Open/Closed and Wide/Narrow—
are all you have to draw on, you get creative about how to utilize them. Things like F just
get pared back to “sort-of closed.” If you were to animate this way and stop the animation
on the frame where the “sort of closed” is
standing in for an F and say, “That’s not an F!”
you’d be right, but in motion, you hardly notice, and what we’re talking about here is
motion, not still frames. As a standard in this book, I’m going to try
not to be concerned
with the individual frames, so much as the
motion and the impression it
gives. If your first instinct is to add more and more and more shapes into the
mix early on, your instinct is to
hide what is wrong instead of
fixing what is
there. Bad instinct; let’s fix it.
Animating lip sync is all smoke and mirrors. What is
really happening
isn’t relevant; it’s all about the impression. How about M? “I need to roll
my lips in together to say M. I can’t do that with
a circle-mouth-thingama-
jig.” Sure you can, or at least you can give that same impression that the lips
are rolled in—just close the mouth all the way; that’s good enough. When
you get the lip sync good enough and focus on the acting, people notice
only the acting. The sync becomes visual noise!
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