Apple Motion 3 - Manual (Page 1141)

Chapter 13 Working with Audio 1141
End Offset: Sets the number of frames from the end of the audio before which the
animation stops. Adjust this parameter to make the behavior end before the end of the
audio track.
HUD Controls
This behavior has a custom HUD, shown below.
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. For more information on applying parameter behaviors, see “
Parameter
Behaviors ” on page 430.
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.
Parameters in the Inspector
Source Audio: Sets the audio track from which to read audio data. Can be set to any
single audio track in the project, or the Master track. Either drag an audio clip or a
video clip with audio into the image well, or use the pop-up menu to choose a source
for audio analysis.
Note: In order for the Audio Parameter behavior to have an effect on an object, audio
must be present in the Timeline at the position of the behavior.
Respond To: Sets the type of audio data analysis to perform. Value can be set to
Amplitude or Transients. If set to Amplitude, the behavior responds to peak values of a
particular frequency. If set to Transients, the behavior responds to rapid changes in
frequency.