9

280 Chapter 12: Animation
can be animated is just to try it. Usually, if you
want to animate a parameter, it can be animated.
Sometimes you need to know in advance if you
can animate a p ar ameter. If so, you can use Track
View. The Track View Hierarchy list displays every
parameter that can be animated. You might also
need to add a controller to a track before it can
be animated. See Track View (page 2–501) and
Animation Controllers (page 2–307).
Usi ng S et Key M ode
The S et Key animation system is designed for the
professional character animator who wants be able
to try out poses a nd then commit those p oses to
keyframes intent ionally. It can also be used by any
animatortosetkeysonspecifictracksofobjects.
This way of working al lows more control than
the Auto Key method, because it g ives you the
chance to try out ideas and discard them quickly
without having to undo work. It lets you pose your
character, and selectively key certain tr acks on
certain objects through the use of Key Filters and
Keyable tracks in Track View.
Note: Although the following information uses the
example of animating a character, it also applies to
animating a complex mechanical assembly.
Straight-Ahead and Pose-to-Pose
Traditional animation is created one of two ways,
either straight-ahead animation or pose-to-pose
animation. Straight-ahead animation is draw n
starting from the beginning and then additional
frames are d rawn sequentially thereafter, mov ing
straight ahead in t ime. Pose-to-pose animation
is created by drawing the important frames
first, (ext remes and breakdowns), and then the
intervening frames are filled in later.
Once a character has been correctly drawn for a
specific frame, pose-to-pose animation requires
that all the keyable tracks needs to b e keyframed.
This creates a pose of the character that will not be
affected if animation for the character is edited at
other points in time. If all the animatable tracks
are keyed in the extremes, the in-betweening work
w i ll not destroy any of those poses.
S et K ey and Pose-to-Pose A nima tion
The number of objects and tracks that require
keying for a character, even a simple character, is
not something that can be easily handled manually.
Set Key makes this process easier by listing all the
tracks that are parts of the charac ter that have to
bekeyedwhenyouwanttofixaposeandcreatea
snapshot in time. Keyable tracks let you determine
which tracks can be keyed, then Key filters let you
work on them selectively, placing keys on only the
tracks you want.
Dif ferences B etween S et K ey a nd Auto
Key Modes
Set Key mode differs f rom Auto Key in a number
of wa ys.
InAutoKeymode,theworkflowisto
turn on A uto Key, mov e to a point in time, then
transform objects or change their p arameters. All
changesregisteraskeyframes.Whenyouturnoff
Auto Key mode, you no longer are creating keys.
Changes made to objects when Auto Key mode is
off are applied globally to the animation. This is
referred to as Layout mode.
In Set Key mode, the workflow is similar,
but the behavior is fundamentally different. Tu rn
onSetKeymode,thenmovetoapointintime.
Before you transform or change object parameters,
you determine the t racks you want to set keys on
usingKeyableiconsinTrackViewandFilters.
Once you know what you plan to key, you try