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Beta documentation · eXLib v0.145.4. Public release is pending.

Work Across Compositions

Reading something that lives in another composition — a controller null in a rig comp, a value in a precomp — without losing your place.

The task

  1. Find out what's in the other composition, and what it's called.
  2. Write a reference to it that resolves.
  3. Get back to what you were doing.

How it goes in plain After Effects

  1. Open the other composition — double-click it in the Project panel — to see its layer names. Your viewer, your timeline panel and your selection all move with you.

  2. Note the exact names. The reference is name-based:

    comp("Rig Controls").layer("Ctrl").effect("Radius")("Slider")

  3. Go back to the composition you were working in, and type that reference into the expression field. AE's own pickwhip drags to properties in the composition you're in, so a cross-comp reference is typed rather than picked.

  4. Re-check the spelling if it doesn't resolve. A renamed layer, or a second comp with the same name, fails silently at the point where the expression runs.

!

comp("Name") resolves by name. Two compositions called the same thing is a real hazard in a project of any size, and nothing in the reference distinguishes them.

What changes with eXLib

The picker reaches the whole project, and After Effects doesn't move.

  1. Open the picker with ⌃⌘R and press Compositions. The layer tree collapses into the project's comp list — roots alphabetical, precomps indented under every parent that uses them.
  2. Filter by name in the same search box ("Filter compositions…"), or just click through the hierarchy.
  3. Click a comp to browse its layers. After Effects stays exactly where it was: the viewer doesn't switch, nothing is selected on your behalf, and the properties come with their live values.
  4. Click a leaf to insert the reference. From a browsed comp it's written comp-qualified — comp("Rig Controls").layer("Ctrl")… — because thisComp would resolve to wherever the expression ends up living.
  5. Active comp takes you back to the composition After Effects has open.

Two things worth knowing:

  • Right-click a comp → Open in tab scopes an editor tab to that composition, and a picker opened from that tab starts there. That's the setup for working on a precomp's rig for a while.
  • Pins carry the composition's identity, not just its name, so two comps sharing a name can't be confused for each other.
✓

When you do want to go there, reveal takes you: double-click the pin chip, or a row in Comp Expressions, or a node in the Dependency Map. It selects the property and activates its composition.

Step by step

Step In plain After Effects With eXLib
1. See what's in the other comp Double-click it in the Project panel and look ⌃⌘R → Compositions, click the comp — its layers appear in the picker
2. Keep your place while you look Not possible — the viewer and selection follow you After Effects doesn't move at all
3. Find the right comp in a big project Scroll the Project panel Filter comp names in the picker; precomps sit indented under the comps that use them
4. Read a current value over there Open the comp and read the property Live values are shown beside the properties as you browse
5. Write the reference Type comp("Name").layer("…")… from memory Click the leaf — the comp-qualified reference is inserted at your cursor
6. Survive duplicate comp names Nothing distinguishes them A pin carries the composition's identity, not just its name
7. Keep working on that comp's rig Switch to it and stay there Right-click → Open in tab: a tab scoped to that comp, whose picker starts there
8. Go back Re-open the comp you were in Active comp
9. Actually jump to a property Find it by hand in the timeline Reveal — double-click the pin chip, a Comp Expressions row, or a map node