Before adding custom parameters to a Custom behavior, you must apply the Custom behavior to an object in your project.
In Motion, do one of the following:
In the Layers list, select the object you want to add a Custom behavior to, click Behaviors in the toolbar, choose Parameter, then choose a behavior from the submenu.
In the Library, select the Behaviors category, select the Parameter subcategory, then drag the Custom icon to the object in the canvas, Layers list, or Timeline.
The Custom behavior is applied to the object. The behavior has no effect until you add a parameter to the behavior.
In the Custom area of the Behaviors Inspector, click the Add Parameter pop-up menu, then choose a parameter to add.
This menu contains every animatable parameter.
The parameter you chose appears near the top of the Custom area in the Behaviors Inspector.
After you add the parameters to animate in your Custom behavior, you can keyframe them in the Keyframe Editor to create whatever animated effect you require. For more information on keyframing parameters to create animation, see Apply keyframes to behaviors.
After you animate the parameters you added, you can save the Custom behavior into the Library for future use. For more information about saving Custom behaviors to the Library, see Save custom behaviors.
In Motion, click the Remove Parameter pop-up menu, then choose a parameter to remove.
That parameter no longer appears in the Custom parameter pop-up menu. Any keyframes applied to that parameter are deleted.
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