Apple Motion 4 - Manual (Page 524)

2 In the Edge Collision HUD (or Inspector), make sure the Affect Subobjects checkbox is
deselected.
When the Edge Collision behavior is applied to a group, and the Affect Subobjects
parameter is turned off, the entire group is “bounced” off the bottom of the screen at
the anchor point of the group.
When the Edge Collision
behavior is applied to a
group and Affect
Subobjects is turned off,
the object (group)
bounces at its anchor
point off the bottom of
the screen.
3 In the Edge Collision HUD (or Inspector), select Affect Subobjects.
Note: The Edge Collision behavior Inspector parameters also include Active Edges controls
for turning on and off the edge of the screen (or Z space) against which an object collides.
By default, an object is deflected from all edges of the screen.
When the bottom edge of each star hits the lower edge of the screen, the star is deflected
and bounces upward.
As the project plays, each star bounces up and down.
Other Simulation behaviors that also use the Affect Subobjects parameter include Align
To Motion, Drag, Gravity, Random Motion, and Rotational Drag.
Example 2: Using the Orbit Around Behavior
The Orbit Around behavior makes an object orbit around another object in a perfect
circle. The parameters of the Orbit Around behavior can be modified to create a more
interesting animation.
524 Chapter 9 Using Behaviors