Apple Motion 3 - Manual (Page 560)

560 Chapter 6 Keyframes and Curves
In many cases, the curve created by your animation can be represented using fewer
keyframes. Often, this will provide a smoother rate of change and will enable you to
take advantage of the various interpolation methods such as Ease In and Ease Out.
You can simplify your keyframes in two ways: either while you are recording them, or
afterwards, by simplifying an existing animation curve. For more information about
simplifying keyframes after recording using the Reducing Keyframes command, see
page 531.
Recording Options
The Recording Options dialog allows you to set the Keyframe Thinning setting, to
record only on parameters that are already animated or to disable recording during
playback.
The Keyframe Thinning setting only applies to recording animation while playing back.
This setting has no effect on ordinary keyframing.
To access Recording Options, do one of the following:
m Choose Mark > Recording Options (or press Option-A).
m Double-click the Animate button.
The Recording Options dialog appears.
Reduce Keyframes option (in Keyframe Editor’s Animation menu) applied to Position Y