Audio Animations

After Effects: Audio Animations

This guide will give you step-by-step instructions to creating an animation that is driven by an audio clip.

To get animations that move in time with sound, you can convert the changing volume level (amplitude) of an audio clip into keyframes and then link those keyframes to an animation property on another layer using an expression.

Guide

  1. Import your audio clip and add it to your composition
  2. Optional:
    • Expand your audio layer so you can see the waveform
    • Drag the In or Out point to trim the layer so you only use the bit of audio you want
    • Drag to reposition the layer in time so the loudest parts of the waveform line up with where you want the animation to be at its largest value:
      Screen%20Shot%202015-09-18%20at%2016.03.21.png
  3. Select the audio layer and choose Animation > Keyframe Assistant > Convert Audio to Keyframes
  4. A new Null Object layer called Audio Amplitude is created that contains the audio keyframes. Expand this layer so that you can see the Slider property for Both Channels, like so:
    Screen%20Shot%202015-09-18%20at%2016.07.35.png
  5. Expand the layer and select the property you want to animate. In the example below it is a layer called Shape Layer 1, and the Scale property will be animated . Choose Animation > Add Expression. Press Enter, or click outside the expression text field to accept the expression (Note: the values of properties with an expression appear pink instead of orange):
    expression.png
  6. Use the expression's pick whip (looks like a snail shell) to connect the expression to the Slider property on the Audio Amplitude layer. Press Enter, or click outside the expression text field to accept the expression:
    pickwhip_slider.png
  7. Play or RAM Preview your composition to see the result.

Reducing the Number of Audio Keyframes

An audio keyframe is created for every frame of the composition. You may find that this means that your animated layer is too jumpy as a result. You can reduce the number of audio keyframes to have a smoother animation, either by manually deleting them, or by using The Smoother:

  1. Select the Slider property, which will select all its keyframes:
    slider_selected.png
  2. Choose Window > The Smoother. Set a tolerance value (higher values remove more keyframes) and click Apply:
    the_smoother.png
  3. The number of keyframes for the Slider property have now been reduced:
    slider_reduced.png
  4. Play or RAM Preview your composition. If too many keyframes were removed, choose Edit > Undo. Repeat steps 1-2 with a lower tolerance value for The Smoother.

Tips

Links

Adobe TV video training for After Effects CS4
Adobe TV - where you can watch lots of videos on Adobe software
Tutorials on keying - removing part of a layer
Video Copilot video tutorials for After Effects
Adobe support for After Effects

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