Graphics Programs Reference
In-Depth Information
Cartoon Ball
Now, let's apply what you've learned about the Graph Editor to the bouncing ball. Follow
these steps:
1. Open the Graph Editor, and look at the ball's animation curves. They should be
similar to the curves in Figure 8.4, shown earlier.
2. Notice how only the
X
and
Y
axes' translates have curves, and yet Translate Z has a
single keyframe but no curve. It's from the initial position keyframe you set at frame 1.
Because you've only moved the sphere in the
X
and
Y
axes, Auto-Key hasn't set any
keys in the
Z
-axis. This is better than pressing S to set keys on everything, so if you
don't have animation on something, it doesn't get keys. Keep your scene clean.
3. Play back the animation, and see how it feels. Be sure to open the Animation Prefer-
ences window. Click the Animation Preferences icon ( ) to set the playback speed
to Real-Time (30fps). You'll find this icon in the Playback section in the Timeline
category.
4. Timing is the main issue now, so you want to focus on how fast the ball bounces:
The ball is falling too fast initially, although the second and third bounces
•
should look fine.
To fix the timing, move the keyframes in the Graph Editor. For the
X
and
Y
axes,
select the keyframes at frame 10 and all the others beyond on both curves. Move
them all back two frames. (See Figure 8.9.)
As the ball's bounce decays over time, it goes up less but still takes the same amount
of time (10 frames) to go up the lesser distance. For better timing, adjust the last few
bounces to occur faster. Select the keys on the last three bounces and move them, one
by one, a frame or two to the left to decrease the time on the last short bounces. (See
Figure 8.10.)
•
Figure 8.9
Move all the key-
frames for both
curves to the right
to slow the initial
fall by two frames,
but leave the timing
the same for
the rest.
