Apple Motion 4 - Manual (Page 1353)

Audio Parameter Behavior
Motion provides an easy and automated way for you to generate audio-driven animations
in your projects, using the Audio Parameter behavior. Whereas other behaviors are applied
to an object as a whole (usually modifying multiple parameters at once), a Parameter
behavior is applied to an individual parameter of an object. The Audio Parameter
behavior—available in the Parameter category in the Behaviors Library (and via the Add
Behavior icon in the Toolbar)—lets you make a particle system pulse to the beat of music,
or have an audio track’s bass amplitude affect an object’s opacity.
To apply an audio parameter behavior via the Add Behavior icon
1 In the Audio tab or Media tab of the Project pane, select the track.
2 In the Toolbar, click the Add Behavior icon, then choose Parameter > Audio from the
pop-up menu.
The Audio parameter behavior is added to the project. No Source Audio is yet applied,
however.
3 Do one of the following:
• In the Behaviors tab in the Inspector, click the To pop-up menu (in the Source Audio
row) and choose a source audio track.
• Drag the audio clip (or video clip with audio) from the Media tab (in the Project pane)
to the Source Audio well in the Behaviors tab of the Inspector.
To apply an audio parameter behavior via the shortcut menu
1 In the Audio tab, select the track.
2 In the Audio Track tab in the Inspector, control–click one of the audio parameters (such
as Level), and choose Audio from the shortcut menu.
The Audio parameter behavior is added to the project. No Source Audio is yet applied,
however.
3 Do one of the following:
• In the Behaviors tab in the Inspector, click the To pop-up menu (in the Source Audio
row) and choose a source audio track.
• Drag the audio clip (or video clip with audio) from the Media tab (in the Project pane)
to the Source Audio well in the Behaviors tab of the Inspector.
For more information on applying parameter behaviors, see Applying Parameter Behaviors .
Audio
The Audio Parameter behavior performs an analysis of a specific property of an audio
track, then applies an animation curve to a parameter based on that analysis.
1353 Chapter 20 Working with Audio