Shapes and Phonemes
The decision of which shapes to build came from two primary
sources. First, Rick Grandy, the technical editor for this book, came
up with a preliminary list, and then the animator, Kyle Clark, came up
with some items that he needed to get this project done. Overall there
were 66 targets built for this animation, and there will probably be
some more that need to be built as more animation is done. Some models
used for production have more than 200 blend shapes modeled. The face
shapes were broken down by region:
- Eyebrows, left, center and right. The shapes created
for this region allowed the eyebrows to animate up and down, slide
inward toward the center or out away from the center, and bow in the
middle upward and downward. Shapes for the brow animate the eyebrows
into even smaller regions: the left, right and center for the left
brow, and the left, right and center for the right brow.
- Eyelids, left and right. The shapes made for the
eyelids allowed for the eye to close, by pulling the upper lid down,
and allowed the eye to squint, by pulling the upper and lower lids to
meet in the center.
- Face (for broad shapes), left and right. The face
groups had shapes that animated the cheeks up and down, moved the
cheeks in and out and puffed the cheeks out and sucked them in. There
was also some cheek deformation on broad mouth shapes, such as the
dread, sneer, smirk and grin.
- Mouth (the largest group), left, center and right.
These shapes created simple as well as complex mouth movement. The
simple movement includes moving the each lip up, down, curl in, curl
out, corner up, corner down, corner side movement inward, corner side
movement outward and shapes that smoothed out the corners of the mouth.
The complex shapes required the modeling of the frown, smile,
furrowing, puckering, pouting, yawning and kissing.
- Overall face shapes, localized by region. These
shapes simply used large areas of the face to accomplish a single task.
This kind of approach is preferable when there is a specific target
that the animator may want to hit with a single blend shape.
These shapes include mouth smirk, mouth sneer, mouth dread, mouth
wince, eye furrow, eye squint and mouth smile.
The mouth regions were extended to include the cheeks, and the eye
regions were extended to include the forehead and eyebrows.
Phonemes are face shapes directly related to speech.
Different theories exist as to which phonemes are required for
animation of speech. Thirteen accepted shapes are recognized as vismemes,
which are used in the creation of English speech.
These shapes are as follows:
- Closed mouth: P in pie, B in book, M in mother.
- Pursed lips: W in wicked, OO in root.
- Rounded lips, corners of the mouth slightly puckered: R at the
beginning of a word, OO in book.
- Lower lip drawn to upper teeth: V in victory, F in French.
- Tongue between teeth with gaps on the side of the tongue: TH in
think.
- Tongue behind teeth with gaps on each side of tongue: L in look.
- Relaxed mouth, mostly closed teeth, tongue visible behind the
teeth: D in dog, T in tag, Z in zebra, S in sit, R in car, N in
nothing.
- Slightly open mouth, mostly closed teeth, corners of the lips
slightly tightened: CHI in chime, JI in jive, SH in shy, VI in vision.
- Slightly open mouth, mostly closed teeth: Y yawn, G in get, K in
kitchen.
- Wide mouth, slightly open lips: EA in meat, I in rip.
- Neutral mouth, teeth slightly parted, jaw dropped slightly: E in
bet, U in but, AI in bait.
- Round lips, jaw dropped slightly: OA in toad, O in rope.
- Open mouth, jaw dropped: A in math, O in shop.
