Using a selection in the compositor
The compositor owns every colour and pixel operation; Layer Comp doesn't duplicate any of it. It handles what node editors are bad at: anything you point at on the image. It only ever adds nodes and links, and never rebuilds your tree.
Use Selection as Factor
This is Layer Comp's adjustment layer.
- Select any node in the compositor: Curves, Hue/Saturation, Exposure…
- Make a selection.
- Click Use Selection as Factor in Select ▸ Compositor.
The selection is saved as a CS Selection N node group and then cleared.
- Grow, Feather and Invert are inputs on the group node. Grow below 0 shrinks.
- A node with a Factor input gets the mask there. If Factor was already linked or below 1, the two are multiplied.
- A node without one (Exposure, Brightness/Contrast) is wrapped: a Mix blends its input and output by the mask, and the node's downstream links move to the Mix.
Saved selections
Photoshop's alpha channels, listed under Select ▸ Compositor.
Button | What it does |
|---|---|
+ | Saves the current selection without connecting it |
Use as Factor of Active Node | Adds another node using the selection; all of them follow when it changes |
Load | Brings it back for editing. Shift adds, Alt subtracts, Shift+Alt intersects |
Update | Replaces it with the current selection |
− | Removes it; its node group is deleted only if no node uses it |
Selection from Node Output
Select a node and click Selection from Node Output to load one of its outputs into the pixel selection: a Cryptomatte matte, a pass, a keyer's matte. It picks Matte, Mask or Alpha first; the redo panel picks another output. The output must be the same size as the image in the editor.
Edit Node on Image
With a spatial node active, Edit Node on Image puts handles on the image that edit the node's own values:
- Box / Ellipse Mask: move, resize, rotate.
- Corner Pin: the four corners.
- Crop: the corners, and move.
- Translate / Transform: move; Transform also rotates.
Shift is precise. Enter finishes. Esc undoes the current drag, or the whole edit. Inputs driven by links can't be dragged.