Apple Motion 4 - Manual (Page 912)

When a Parameter behavior is applied to a parameter, a Behaviors icon appears in the
Animation menu for that parameter. In this example, the Behaviors icon appears in the
Animation menu for the Spike Opacity parameter.
Behaviors icon
4 Click Play (or press the Space bar).
Because the Randomize parameter behavior is applied to the opacity of the star spikes,
the star appears to flicker.
Flickering star over
a background image
912 Chapter 15 Working with Generators