There
are many approaches to modeling
the human. Most of these methods
were designed to accomplish specific
aims such as easier sculpting
of facial features, better facial
animation, easier texturing, and
so on. Of all these techniques
subdivision or subpatch modeling
has the scope to achieve all the
necessary objectives for modeling
a realistic human and its subsequent
goals of lifelike movements and
facial expressions.
This
chapter outlines a method for modeling
a human female. If your desire is
to model a male, then you can refer
to my other book 3D Human Modeling
and Animation, 2nd Ed. (John Wiley
and Sons Publishers).
Although
most of human modeling will be examined
in this chapter, the following chapter
7 will cover details such as hair,
eyes, teeth, and so on. It is recommended
that you work from photographs and
also photographic templates that show
front, side, back, and perhaps top
views of the figure.
In
the previous chapter 2 you learned
how to model a figure with clothes.
This time the human will be undraped
so as to make one more aware of human
anatomy. During the greatest ages
of art, the nude inspired the greatest
art works. Even when it no longer
held sway over art movements, it still
retained its importance in the academic
training of artists.
The
Greeks in the fifth century taught
us that the nude is not just a subject
to be studied and imitated but an
art form in itself. Their knowledge
gave us an understanding of the actions
and structural characteristics found
in the nude. Artists who painted and
sculpted the nude learned to convey
weight, rhythm, mass, line, value,
texture, and tension.
To
be successful in depicting the human
body one needs to have an understanding
of anatomy. Perceiving the nude means
understanding it. Without any knowledge
of anatomy, it is impossi- ble to
recognize the inherent form of the
nude.
Anatomy for the artist does not imply
a doctor’s understanding of
the body. Internal organs, blood vessels,
muscles, and bones that are not visible
at or below the skin surface are not
a concern to the 3D modeler.
The
3D animator should have knowledge
of the skeletal/muscular system and
the manner in which it works as a
mechanical device. Without this understanding
it is very difficult to portray the
human character in its various attitudes
and movements.
There
are many excellent books on human
anatomy for artists. This book does
not pretend to be one of them. The
study of anatomy requires an entire
book devoted to the subject. Anyone
who is serious about studying 3D human
modeling and animation should have
a collection of anatomy books.
The
various steps in this chapter that
describe the manner in which to model
the figure also contain some illustrations
of human anatomy. These pertain to
the specific modeling task at hand.
The anatomy illustrations are only
meant as a visual guide to help you
see what lies below the surface of
the part that will be modeled. They
do not identify their individual anatomical
details with medical names. If you
wish to know the designations of different
bones and muscles, they can be found
in anatomy textbooks or online.
Even
though males and females have their
differences, they are structurally
homological to each other. Fat deposits
and variations in their skeletons
account for the greatest deviations.
The
greater quantity of fat in the female
makes her appear smooth and flowing.
Aside from sexual differences, she
is normally smaller except in the
hips.
The
difference in the skeletal structure
makes the female slighter in proportion.
Her head is smaller and positioned
relatively higher than the male. The
brow ridges, unlike the male are nearly
absent adding to the forehead’s
smoother and more rounded appearance.
The width of the shoulders to that
of the trunk is smaller. In fact,
it is the opposite to the male whose
shoulders are wider than the hips.
The thyroid cartilage (Adam’s
Apple) is flat compared to the prominent
one in the male.
The
trunk of the female in contrast to
the male has a shorter rib cage with
the outwardly visible breasts. The
female pelvis is shorter but wider
and deeper and leans forward. At the
base of the spine, the sacrum is broader
and inclines behind to form a full
triangle. The two dimples of this
triangle are clearly visible. Due
to a wider pelvis and fat deposits,
the female is broader at the hips.
The side between the ribs and hipbone
is longer owing to the female’s
shorter rib cage and pelvis. The buttocks
extend to a lower level than the male.
The female also has a smoother more
rounded abdomen with a deeper navel.
The
female upper arm is shorter resulting
in a higher location of the elbow.
When the arms are resting at the sides
of the body, the finger tips extend
to a higher point at the thigh. The
wrist and hand are smaller.
The
wider hipbones separate the legs in
their pelvic sockets to a greater
degree. This makes the legs slant
more toward the knees. The knees are
fleshier but the kneecaps and their
ligaments are less obvious. The calves
located below the knees are lower
on the female. The feet are smaller.
Artists
throughout the ages have tried to
calculate the average size of a human.
Despite all that, we still do not
know the normal scale of the figure.
Classic Greek and Renaissance bodies
were 8 heads tall. Mannerists such
as El Greco and Pontormo painted long
figures measuring 9 heads or more.
The
French anatomist Richer was the first
to formulate that the traditional
measurement of the average human was
about seven and one-half skull-lengths.
Although in real life a figure of
that height would seem well proportioned,
on a 2D sur- face the body appears
much broader and stockier. To remedy
this, artists have found that when
portraying the nude as 8 heads tall,
the figure appears more slender and
graceful.
One
of the more difficult tasks for computer artists
is to model objects in the right proportions.
Therefore, in order to simplify your work and
help you model more accurately, it is recommended
that you take digital pictures of a nude figure.
It is also advisable to take close-up views
of the head, hands, and feet. Perhaps someone
will create an online repository of assorted
nude figures in their various poses. As more
artists contribute to the site, these should
serve as an invaluable aid to 3D modelers.
Modeling the Head
Before
starting to model the face, it is
recommended that you study the various
muscles and their purpose. While reading
about these muscles, you may want
to use a hand-held mirror to observe
their effects on various expressions.
The
Skull
Since
the muscles of the head are thin and
flat, it is the shape of the skull
that dictates the overall form of
the head. Figure 6-1 illustrates various
views of the skull. Visualizing the
skull beneath the head makes it easier
to see their respective masses that
shape the face.
Fig.
6-1 Some of the more prominent features
of the skull that affect the contours
of the face are the forehead, eye
sockets, nasal bone, cheekbones,
the empty pockets between the jaw
and cheekbones, and the chin.
The
Muscles of the Head
It
is important to note that
no skeletal muscle acts
on its own. When one muscle
contracts or draws together
its fibers, it activates
other, opposing muscles,
which in turn, modify
the action of the original
contracting muscle. Normally,
the head is broken up
into three sets of muscles.
Most of these are small,
thin, or deeply embedded
in fatty tissue. A few
of the muscles shown in
Figure 6-2 warrant special
attention. They play an
important role in facial
expressions and help define
the contours of the face.
Fig.
6-2 The muscles of the
head are divided into
three groups: scalp,
face, and mastication.
