Figure 5-1. Linear interpolation
Ease Out, Ease In, Ease Both
The Ease family of interpolators is used to create more natural animations than simply linear
animations. In real life, objects don't suddenly stop, nor do they transition from stopped to moving
without a period of acceleration. An object being animated with an EASEIN interpolator starts out slow,
speeds up for a short period, then travels at a constant speed for the remainder of the animation.
Conversely, a node being animated with an EASEOUT interpolator starts moving much like a linear
interpolation, but just before the end of the animation the node slows to a stop.
The interpolator EASEBOTH combines these two periods of acceleration and deceleration into a single
animation, so a node will start slowly, travel at a constant speed, then slow to a stop. The screenshot in
Figure 5-2 presents the EASEBOTH interpolator, showing the slight curves at the beginning and end of the