Apple Motion 3 - Manual (Page 490)

490 Chapter 5 Using Behaviors
Other Simulation behaviors that also use the Affect Subobjects parameter include Align
To Motion, Drag, Gravity, Random Motion, and Rotational Drag.
Example 3: Using the Orbit Around and Vortex Behaviors
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. The Vortex behavior is the opposite of the Orbit Around
behavior—Orbit Around causes one object to orbit around another target object,
whereas Vortex exerts a force on all objects surrounding the object to which the Vortex
behavior is applied. The following examples use the same group of layers (circles) used
in “
Example 2: Using the Gravity and Edge Collision Simulation Behaviors ” on page 487;
however, the layers are repositioned in the Canvas.
Using the Orbit Around Behavior
You create animation using the Orbit Around behavior by specifying a target object
that other objects circle around. You set the target object by dragging the object to the
Object well in the Orbit Around Behaviors tab.
To use the Orbit Around behavior:
1 In the Layers list, click the Add button (+) to create a new group.
2 Option-drag the “sm circle” to the new group.
A copy of the layer is added to the group.
3 Rename the “sm circle” to “center circle” and position the layer in the center of the
Canvas.
4 Apply the Orbit Around behavior to the “circles 1” group.