Nodes · Comp
Merge
Compv3coreConcat: Pointwise
Overview
The node you will use most. B is the background and decides the format; A is the foreground. Twenty-three operations cover the Porter–Duff coverage set, the arithmetic set, and the tone set.
How to
- Wire the background to B, the foreground to A.
- Choose
operation—overunless you know otherwise. - Stack more foregrounds on
A2…A8rather than chaining Merges when they share a background.
Inputs
| Input | What it takes |
|---|---|
| B | the background — **B decides the format** |
| A | the foreground, composited over B |
| A2 | — |
| A3 | — |
| A4 | — |
| A5 | — |
| A6 | — |
| A7 | — |
| A8 | — |
| mask | limits the effect to this matte — the engine's universal mask slot, applied for every node that declares it |
Outputs
| Output | Type |
|---|---|
| out | Image |
Parameters
| Parameter | Type | Default | What it does |
|---|---|---|---|
| operation | Choice | over | How A combines with B: over (normal comp), disjoint-over (heals the dark shared-edge line when alphas overlap or double-premultiply — the keying staple), conjoint-over, matte (over with an unpremultiplied A), plus, screen (video-space; on values past 1 it becomes max, never inverting), hypot (HDR-safe glow merge), multiply, minus, max/min, and the rest of the Porter–Duff family. An unknown name composites as over and says so on the node. overdisjoint-overconjoint-overmatteunderinoutatopxormaskstencilcopyplusminusfrommultiplydividescreenhypotdifferenceexclusionmaxminaverageoverlayhard-lightsoft-light |
| mix | Float | 1.0 | Dissolves the whole merge back toward plain B. 0 = B untouched, 1 = the full operation. |
| bbox | Choice | union | Which data window the result keeps: union (default), intersection, or one side. unionintersectionAB |
| disabled | Bool | false | Bypass: the node passes its first input through untouched (D in the graph). The knobs keep their values for when it comes back. |
| label | Text | A note shown under the node in the graph — what this node is FOR. Never affects the render or the cache. | |
| hide_input | Bool | false | Draw the node without its input wire — a tidy graph for a node whose source is obvious (a Dot, a viewer tap). |
Known edges
Merge never resamples. An A of a different size composites pixel for pixel; if you wanted it scaled, that is a Resize.