Create an Expression - Pick Whip (spiral icon)
1. Option+Click on the Stop watch (on mac)
(this reveals the transform value for that keyframe for example the Rotation or the Scale)
2. Click and Drag the Spiral icon to the thing you want to copy. For example you can drag the spiral to the rotation of a different object.
3. Click in the timeline to accept the nex value (or click the extended keyboard enter)
4. The layer will copy the value of the other layer.
To temporarily disable the expression
1. Click the = iconand it turns to a ≠
To disable the expression
1. Select the text in the expression box and delete it
1. Hold Option key when you hit the = icon
Modify the Expression
Change the text in the expression box
Multiply its Value
At the end of the expression enter *2
You can enter negative values to go opposite directions
Expression Language Menu
The triangle button next to swirl give you a bunch of choices of preset values
Key Board Shortcuts
Expose the Keyframes
Expose only the Expressions of a layer
Convert Audio to Keyframes1. Insert Audio track
2. On that layer right click.
3. Keyframe Assistant
4. Convert Audio to Keyframes
AE generates a brand new layer called a Null object
Its just a dummy layer
Select the Audio Amplitude layer
Inside you will see right channel, left channel, both channel
To work with only with the both channel
Option+Shift and click on the Right Channel, then left channel
This removes them from the view in the timeline (it doesn't delete the keyframes)
Connect a layer to the audio file
Once the audio is converted to key frames
1. use the pick whip and drag it to the slider property
2. click the blank area to accept the expression
As soon as there is any volume in the audio track the property is shown.
Modify the expression
On the audio key frames (slider) Select smoother from the window menu.
Adjust the tolerance of the smoother.