Precomps are a way of nesting compositions inside other compositions. This allows you to create more complicated animation relationships and also helps you keep your timelines more organised.
Precomping is similar to the way you group layers in Photoshop. In fact, if you import a PSD into After Effects, the file layers are automatic precomposed in the AE assets bin.
The main reasons you would use precomps:
- To organise and simplify your timeline.
- Add complexity by incorporating animations within animations.
- To keyframe the properties of an a completed animation
To precompose assets in After Effects:
- Select the Layers you want to Precompose in the timeline.
- Choose to Layer > Precompose.
- You can choose to leave attributes in the current composition or move them to the new composition. Moving the attributes will incorporate any keyframes that have been applied to layers.
- You can also name your new precomp.
- You can edit the precomp by double clicking it in the timeline.
You can also right click on layers in the timeline and select the precomp option there.
The keyboard short cut to precomp is Shift+Command+C.
You can also manually precomp compositions by adding one composition to the timeline of another.
In the following video, I take you through the build of a simple scene transition. The transition uses multiple precomps to add detail to the animation.
Finished project
I used a couple of Pexel vids in this demo. A shipwreck and some jelly fish.
