Beat Detection iExpressions can be applied to properties which represent the audio amplitude of some music (i.e. properties which you created with the function 'convert audio into keyframes' of the keyframe assistent). They can detect the beats in the music such that you can animate various properties according to the music. The beat detectors just recognize the beat and don't do any animation, yet. You can animate properties using other iExpressions (like the 'Change on Beat 1D') which are then linked to the beat detector. This setup allows to animate several properties according to the same beat. To use the 'Beat Detector from Marker', you need to play the music and set marker according to it as if you would tab along with the rhythm. The iExpression then generates one beat for each marker. If you reapeat a regular pattern with the markers at least three times, the iExpression automatically continues this pattern if you enable the option 'continue automatically'.

  • continue automatically

    enables the iExpression to detect the regular pattern in the marker placement and to continue it automatically.

  • Fade In/Out
    Fade In Duration

    determines the number of frames over which the beat is faded in. If this is set to 0, the iExpression abruptly jumps on each beat from 0 to 100. If it is set to 10, the value starts already 10 frames earlier to slowly increase from 0 to 100.

    Fade Out Duration

    determines the number of frames over which the beat is faded out. If this is set to 0, the iExpression abruptly jumps after each beat from 100 to 0. If it is set to 10, the value slowley decreases over 10 frames from 100 to 0.

    Fade Type

    determines whether the beat signal fades in or out in a linear or exponential fashion.

Beat Detector from Marker iExpression

can be applied to: 
1D properties
iExpression Bundle: 
Download at aescripts.com

What are iExpressions?

iExpressions are After Effects expressions with an easy to use interface.