2011

Animation Concepts
Simply defined, animation is a simulation of movement created by displaying
a series of pictures, or frames. From one frame to the next certain values are
changed. Almost all values can be animated. A value can be anything from
the position, rotation, scaling, or transparency of an object, to the gamma,
gain, or offset in a color correction.
Keyframe Animation
Keyframing is the simplest form of animating an object. It is based on the
notion that an object has a beginning state, or condition, and changes over
time in position, form, color, luminosity, or any other property to some
different, final state. Keyframing takes the stance that we only need to show
the keyframes or conditions that describe the transformation of the object,
and that all other intermediate positions can be figured out from these—see
Keyframing and Interpolation on page 660 and Setting Keyframes on page 660.
Keyframing and Interpolation
When you keyframe, you determine what an object looks like at specific points
in time, while algorithms fill the frames in between the keyframes. This
technique is called in-betweening. The intermediate values between the
keyframes are computed by interpolation.
Extrapolation is used to determine the behavior of a channel before the first
or after the last keyframe—see
Modifying Interpolation on page 687.
Setting Keyframes
You can set keyframes for just about anything that has a value, including an
object transform, visual attribute, as well as any tool attribute. When you set
a keyframe to animate a particular parameter, a function curve is created. The
curve is a graph that represents the animation of that parameter over time.
You can edit the animation by editing its curve in Animation Editor or by
modifying the attribute values in the Tool UI. You can set keyframes manually
or automatically—see
Setting Keys Manually on page 676 and Setting Keyframes
Automatically
on page 680.
660 | Chapter 27 Animation