Motion Array Posts a Free Script that Creates Inertia and Bounce Using Expressions.
Bouncing, the idea of secondary action and inertia is a subject that gets brought up quite often in After Effects communities. One way to automate this process would be through expressions which drive other keyframe settings on your own time schedule with scripts like EZinertia from Motion Array!
The script uses expressions to drive the inertia effect, and the accompanying tutorial shows how to use these expressive techniques for a more stylized bounce. “With this effect you can create an unrealistic but stylish bouncing animation that would be difficult or time consuming with other methods,” says MOtion Array’s Owen Chikazawa.”
It also has some easy ways of applying changes quickly from one control layer as opposed do having multiple layers all linked together through actions in After Effects which is not always user-friendly depending on what kind of work flow you have going on at any given moment.”