The Fuzzy Border between Modeling and Animating ◾ 245
Next, the cap, hair, and fur are placed on
the character’s head. At this point, the cap was
sculpted to t the desired pattern of hair on
our character. We make sure the timeline at
the bottom of the Main Window is set to the
rst frame. With the reshaped sphere and the
nHair selected, we choose:
nDynamics Main Menu → nHair → Display
→ Current Position
is is seen in Figure8.29.
Our character, which has a pink Blinn
surface, has yellow hair. e hair can be
seen in the rendering in Figure8.30, taken
at frame 1. Figure8.31 shows us the corre-
sponding top view of the hair. e hair sys-
tem is a dynamics eect, and to activate it,
we hit the play button on the bottom right
of the Main Window. We saw in the Trix
example that when we created the nDy-
namics eect, a nucleus tab appeared in the
attribute box; similarly, the nHair dynamics
eect has a nucleus tab in its attribute box,
where we nd elds that animate the hair
over a series of frames. So, the hair moves,
and it pulls the fur along with it, as seen in
FIGURE 8.28 (See p. CI-14 of Color Insert)
Resized sphere.
FIGURE 8.29 Current position.
FIGURE 8.30 (See p. CI-14 of Color Insert)
Pink man with punk yellow hair.
FIGURE 8.31 Top of head before.
246 ◾ 3D Animation for the Raw Beginner Using Maya
Figure 8.32. e hair/fur combination will
move every time we run the animation.
is example illustrates a common tech-
nique seen in animation applications. One
object that is easy to animate is used to ani-
mate another object. e nHair, which is a
dynamics eect and will react to the timeline
being played, is bound to the Fur object, so
that it will move in turn.
Finally, we need to prevent the hair cap
from rendering. We can do that by going to its
attribute box, nding the Render Stats tab, and
unclicking Primary Visibility. We should also
uncheck Visible in Reections and Visible in Refractions (see Figure8.33).
USING BLEND SHAPE TO ANIMATE THE LEG OF THE CHICK BEING BORN
We are going to look at a handful of tools that are called “deformers.” ey can be used to
cra the surface of a model. ey can also be used to animate a model, as deformers can be
keyframed to change the shape of an object over a series of frames.
e deformers are found in Maya under the Animation Main Menu. ere is a cluster
of deformers listed under Nonlinear, and we will look at one of them. But we will start
out with the one that is not on the nonlinear
deformer menu dropdown.
Animating a Chick Leg
with a Blend Shape
We will focus on Blend Shape now, a partic-
ularly powerful deformer that is frequently
used to simulate repetitive, organic motion,
such as mouths that break into a smile and
then lose that smile, eyes that blink, or a
heart beating.
Here is the simplest way to use a Blend
Shape. We create a model and make two or
more copies of it. We then alter the shape of
the copies to make them look dierent. en
we use Blend Shape to morph the original
model using the altered copies as templates
for the morphing process. us, the outer
shape of the original model is animated by
transforming the geometry through vari-
ous stages based on the deformed shapes of
the copies.
FIGURE 8.32 Top aer turbulence.
FIGURE 8.33 Making the cap invisible.
The Fuzzy Border between Modeling and Animating ◾ 247
Let’s add a leg to our cracked egg. e foot will
have four toes, and we will animate the leg and
the toes using a Blend Shape. In Figure8.34, we
see the polygon leg in the egg, kicking its way
out. ere are also two copies of it sitting outside
theegg. ese two will be removed from the scene
later. ey have been manipulated to change their
shape and will serve as two morph points; we will
use these to animate the chick’s leg.
Now, we Shi-select, in this order: the rst
copy, the second copy, and the original. It is
important to choose the original last.
en we choose:
Animation Main Menu → Create Deformers → Blend Shape (see Figure8.35)
Now, as shown in Figure8.36, we choose:
any Main Menu → Window → Animation Editors → Blend Shape
is pulls up the window we will use to control the Blend Shape animation. In Figure8.37,
we see three dierent images taken of the Blend Shape Editor. e way we use this window is
as follows: First, we select frame 1 on the Timeline. We then move the sliders and we see that
the leg in the egg moves. en we hit Key All. en we select frame 20. We move the sliders
to dierent positions and hit Key All. We do this one more time, choosing frame 40, moving
the sliders, and hitting Key All. (We see that when using Blend Shape to create an animation,
we set our keyframes in the Blend Shape Editor, not on the Timeline.)
e renders that we get at frames 1, 20, and 40 are shown in Figure8.38. We see that the
two sliders have been used to move the leg inside the egg from its original shape into some
FIGURE 8.34 Chick leg and two copies.
FIGURE 8.35 Creating a nonlinear Blend
Shape deformer.
FIGURE 8.36 e Blend Shape Editor.
248 ◾ 3D Animation for the Raw Beginner Using Maya
FIGURE 8.38 (See p. CI-3 of Color Insert) e chick breakout.
FIGURE 8.37 Keyframes for Blend Shape.
The Fuzzy Border between Modeling and Animating ◾ 249
combination of the two copies, and by moving the sliders dierently, we get dierent nal
forms of the leg.
ere are two other sets of keyframes used in this rendering. One was used to animate
the pieces of shell as they break o and y away. e other was used to push the leg outward
a bit as he escapes.
We can remove the two copies of the leg, and then render the scene as video. Maya will
interpolate, giving us an animated chick leg trying to kick its way out of the shell.
USING A BEND DEFORMER TO ANIMATE ROLLING UP A POOL COVER
Now, we move into a set of deformers that are called “nonlinear.” ese are deformers
that, unlike blend shape, do not intrinsically change an object over time. Nonlinear
deformers can be used eectively to cra the surface of a model. By adjusting the set-
tings of a deformer tool over a series of keyframes, we can also use it to animate the
morphing of an object. Since each nonlinear deformer uses a dierent, but specic
mathematical algorithm, they can be used to alter the appearance of models in math-
ematically elegant ways.
Here, we will look at Bend. e various nonlinear deformers have very dierent
behavior—and all of them are easy to use. Try experimenting with them.
The Bend Deformer
We nd the set of deformers under the listing “nonlinear” on the Create Deformers drop-
down (on the Animate Main Menu). Like many of the tools in Maya, their settings can be
controlled with either an iconic handle or by using a Settings box.
e Bend deformer can be used to put a bend in a piece of plumbing or ductwork or to
create a wound-up garden hose.
We animate with the nonlinear deformers dierently than we animate with Blend Shape.
We use a deformer to incrementally alter the form of an object, and then create a series of
varying keyframes (using the S key) with the object deformed dierently at each keyframe.
We could, for example, animate the backward bend and forward snap of a catapult.
We are going to use it to roll up a pool cover. Essentially, the bend deformer can warp an
object into a smooth arc, and the degree of the arc can be precisely controlled.
Animating a Swimming Pool Cover
To make a pool cover, we will need a pool, at least a simple one. Figure8.39 is a basic wire-
frame model of a pool with a cover over it. Notice that the pool cover is a attened cube,
only one polygon thick, with a signicant amount of geometric detail running parallel to
the edge of the pool—something we will need to get the cover to roll up smoothly.
With the pool cover selected, we choose:
Animation Main Menu → Create Deformers → Nonlinear → Bend (see Figure8.40)
If we pull up the settings for the deformer, as shown in Figure8.41, we see that the curva-
ture has been set to a high negative number. We have set the high bound to 5.
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