304 ◾ 3D Animation for the Raw Beginner Using Maya
these dierences. ey are all accessible
by choosing:
Animation Main Menu → Muscle
Maya supports “capsules,” which are
rigid and can be used to make joints appear
solid. We can convert joints into capsules
so that the joints have geometry that will
deform the skin that moves over them.
Maya also supports “bones,” which are sim-
ilar to capsules, except that we can control
their geometry. (ese bones have noth-
ing to do with the bones that get laid down
between joints as we build a skeleton.)
Maya also supports “muscles,” which are
attached beneath the surface of your charac-
ter’s skin. ey will cause the skin to deform.
Each muscle is connected in two places, and
when the limb is extended, the two connec-
tion points will move apart and the muscle
will extend itself. As the limb is closed, the
FIGURE 11.11 Maya’s three solvers.
FIGURE 11.12 e Rotate Plane solver.
Specialized Animation Techniques ◾ 305
two connection points will move closer and
the muscle will bulge outward.
Making a smooth binding look realistic
by inserting these three sorts of constructs is
a complex task. For the new user, this typi-
cally involves much experimentation and
iteration.
ere is actually a simpler, although less
powerful, alterative to the muscle system in
Maya. It can be used to signicantly improve
the naturalness of joint movement in Maya,
and it gives us a feel for the importance of
placing hard objects underneath the skin of a
character. is technique involves the creation
of “inuencers” below the skin of a character.
We are going to do some careful analysis of how Hiro bends. In Figure11.13, the wrist
eector has been moved, causing the shoulder and elbow joints to move. Notice the unnat-
ural folding of the elbow. It is almost like it is made of paper.
Now, in Figure11.14, an egg-shaped polygon sphere has been placed just under
the skin, and overlapping the boundary of the joint and the lower arm bone. In
Figure11.15, the sphere and the elbow joint have been Shift-selected. In Figure11.16,
we have chosen:
Animation Main Menu → Skin → Add Inuence
is allows the sphere to aect the geometry of the elbow as it exes. (e default settings
for this tool have been used; they appear in Figure11.17.)
en we move the wrist again, and the improvement is obvious (see Figure11.18).
FIGURE 11.13 (See p. CI-14 of Color Insert) A
folded elbow.
FIGURE 11.14 Inserted egg.
FIGURE 11.15 Egg and skin selected.
306 ◾ 3D Animation for the Raw Beginner Using Maya
Controlling the Movement of a Skeleton: Pinning and
Constraining, and the Sticky Checkbox
We have seen that IK handles control the overall movement of the skeleton, and that the
thing we actually use to move the skeleton is called an eector; the le wrist eector is a
green loop in the Maya Main Window, and because of the view perspective, appears as a
FIGURE 11.16 Adding an inuence.
FIGURE 11.17 Default inuence settings.
Specialized Animation Techniques ◾ 307
narrow ellipse in Figure11.19. In Figure11.20, we see the hip eector; this is an important
one, as the root of the skeleton is at the hips.
In Figure11.21, we have used the Move tool to push the hips toward the ground (i.e.,
the x-z plane). Notice that the feet stay put, and as a result, the knees and ankles bend. In
Figure11.22, we are “unpinning” the le foot. Now, when we push down on the hips, we
get the result seen in Figure11.23.
FIGURE 11.18 (See p. CI-14 of Color Insert)
An improved elbow.
FIGURE 11.19 e wrist eector.
FIGURE 11.20 e hip eector.
FIGURE 11.21 IK pink man squatting.
308 ◾ 3D Animation for the Raw Beginner Using Maya
A common technique to use while animating a human is to cause part of the skel-
eton to be aimed at an object. In Figure11.24, we see our pink man kicking a ball.
In Figure11.25, we Shift-select the ankle effector of the left leg and the ball, then we
choose:
Animation Main Menu → Constrain → Aim
Now, we move the ball forward, and the pink man’s foot follows it, apparently kicking the
ball (see Figure11.26).
ere is another setting that can be used to enhance the richness of a character’s move-
ment. In Figure11.27, we have generated another skeleton. Instead of generating the cor-
responding rig with Maya’s skeleton building tool, we are putting in two shoulder-to-wrist
IK handles manually using the IK Handle tool. In Figure11.28, we see the settings for the
IK Handle Tool; for the le hand we did not check o Sticky, but for the right hand we did
check it o. en, when we pull down on the hip, the right wrist is stuck where it is in the
scene, seemingly (but not really) stopping when it comes into contact with the plane (see
Figure11.29).
FIGURE 11.22 Unpinning the le foot. FIGURE 11.23 e result—foot breaks through.
..................Content has been hidden....................
You can't read the all page of ebook, please click here login for view all page.