5

Each time the project is used, the size and position of the background generator must
change to match the length of the text. Also, the lens flare must only appear on top of
the letters. Using a rig, you can create a small set of controls that modify the parameters
such changes require. That way, rather than selecting individual objects, open their
respective Inspectors, and make those changes, you can select the rig and have instant
access to the parameters to change.
Alternatively, you can publish the widgets and use the Project object (in the Layers list)
as a custom control pane in the Inspector. For more information about publishing, see
Publishing Rigs.
You can even apply keyframes to a slider widget to create dynamic animated effects
based on saved snapshots in the slider. Pop-up menu and checkbox widgets cannot be
keyframed, nor can they accept behaviors.
496 Chapter 10 Using Rigs