Chapter 9. Keyframe Interpolation
In Chapter 7, “Properties and Keyframes,” you learned to animate layer properties over time by setting keyframes. By defining only the most important, or key, frames, you assume the role of head animator. After Effects fills the role of assistant animator, providing all the in-between frames, or tweens, using what’s known as an interpolation method to determine their values.
Fortunately, you can instruct your assistant to use a range of interpolation methods. Some methods create steady changes from one keyframe to the next; others vary the rate of change. Movement can take a direct path or a curved route; an action can glide in for a soft landing or blast off in a burst of speed.
Without a choice of interpolation ...