Graphics Programs Reference
In-Depth Information
Selection Handles
Using selection handles makes selection easier and work flow faster, so turn on selection
handles for each of the groups you're animating. Select the wheel groups in the Outliner,
and then choose Display
➔
Transform Display
➔
Selection Handles. Select the wheel arm
groups, and turn on their
selection handles as well.
Figure 8.45 shows the
selection handles enabled
for the wheel, pump arm,
and wheel arm.
How selection handles
work depends on Maya's
selection order.
Selection
order
, which you can cus-
tomize, sets the priority
of one type of object over
another when you try to
select in a work window.
After the selection handles for the locomotive's wheels and drive arms are turned on,
only the handles will be selected (and not the whole locomotive) when you make a mar-
quee selection that covers the entire locomotive. Handles have a high selection priority by
default, so they're selected above anything else.
Figure 8.45
Selection handles
make selecting a
group of objects
much easier.
Animating the Locomotive
Animating most of the locomotive is straightforward. Simple rotations will make the
wheels turn. Translating the locomotive's top node will move the entire object. This,
however, leaves out the drive mechanism with the steam pump and the wheel and pump
arms. You'll rig these to animate automatically in the next chapter, using IK handles and
connections.
Animating a Catapult
As an exercise in animating a system of parts of a model, before you continue to animate
the locomotive in the next chapter, you'll now animate a catapult. This catapult model is
straightforward to animate. You'll turn its winch to bend back the catapult arm, which
shoots the projectiles, and then you'll fire and watch the arm fly up.
First, let's get acquainted with the scene file and make sure its pivots and hierarchies
are set up properly. The scene file
catapult_anim_v1.mb
in the Catapult_Anim project on
the CD has everything in order, although it's always good to make sure. Figure 8.46 shows
the catapult with its winch selected and ready to animate.
