First off, I like to get
my parts named, starting with the lower teeth
- I called them "Lower_Teeth" of all the
zany names. Next, I selected the jaw area
(all the parts which will be mobile, I think),
and named those parts "Lower_Jaw" (remember
to name the Part Not the Surface!).

Before you proceed to
the setup for the mouth targets, it is strongly
advised that you test the results of editing
your jaw. Select the two parts (teeth and
jaw) and test rotate them (see the yellow "x" and
direction arrow in the illustration) to see
ho the whole thing looks when you do a big
jaw-dropping take. If no serious errors result
(like the lips get left behind, or the neck
doesn't seem to be moving right) then carry
on.

Create new morph target
called "Mouth.Ahhhh".

The actual posing of the
jaw can be pretty easy, if you are comfortable
with the Magnet and Pole tools. Take a look
at the example below; I've made a new selection,
and renamed that part for now, as shown below.
By selecting this area and setting the falloff
of the magnet so it has high influence at
the front of the jaw, and less at the back,
we can rotate the jaw down into position
with one drag of the mouse.

Next, I changed
the selection to include the rest of the
jaw area, and the teeth, and used the magnet
volume shown below to get the lips, teeth,
and the interior of the mouth into position.

Once you've done with
that, tweak the corners of the mouth, and
you should have something like the image
shown below (well, you may not have a tongue).

Now choose "Copy map" in
the Maps tab, and name the copy "Mouth.Left,
as shown below. Use the various tools to
close the mouth just a bit, and then skew
it off to the left (in the Back view) so
we can make one of the positions needed for
a "Aarhaagh Aarhaagh Aarhaagh" side-to-side
laughing motion. You might want to close
the mouth a bit more than I have.

Make another copy of the
vertex map, and repeat the process, but to
the right. I get a bit of distorting when
I do this. Decide for yourself if it is within
tolerance (again, test in Layout) before you
invest a bunch of time in setting up morph
targets.

If you take a look at
the areas circled in the example, you'll
see some of the most common areas where problems
occour. This happens because the data in
those crowded areas has gotten crammed together,
and some of the patches have extremely irregular
orientations relative to their neighbors.
It can often be fixed with judiscious use
of the Smoothing tool. I selected the offending
patches, and smoothed them with a strength
of 2 and 5 Iterations, as shown below.

This fixed it up pretty
good. Once you've gotten to this point, pull
out the chart of phoneme morph targets, and
build them, being sure to name them appropriately
(according to the sound they represent).