# DeepMerge

> Combine two deep streams (or hold one out by the other).

| Node | DeepMerge |
|---|---|
| Menu | Deep › DeepMerge |
| **Names in each format** | |
| .oink comp (JSON) | `"type": "OC_N_deepmerge"` |
| .nk script | `DeepMerge2`, also imports `DeepMerge` ([how .nk import works](/docs/nuke-users/nk-import)) |
| Python | `nuke.createNode("DeepMerge2")` |
| Assistant (MCP) | `create_node(type="DeepMerge")` |
| Tab search | `deepmerge`, or its initials `dm` |

![DeepMerge properties](/shots/nodes/deepmerge@2x.webp)

## Inputs and outputs

| Port | Name | Type |
|---|---|---|
| input 0 | B | image |
| input 1 | A | image |
| output 0 | Image | image |

## Knobs

Panel tab **Deepmerge**, in panel order.

| Knob | Label | Type | Default | Range / values | .nk knob | Description |
|---|---|---|---|---|---|---|
| `operation` | operation | menu | `combine` | combine, holdout | `operation` |  |
| `drop_hidden` | drop hidden samples | bool | `false` |  | `drop_hidden` |  |

### Other knobs (Python, .nk and the assistant; not on the panel)

| Knob | Label | Type | Default | Range / values | .nk knob | Description |
|---|---|---|---|---|---|---|
| `gl_color` | Viewer Controls Color | float ×3 | `0, 0, 0` | 0 to 1 |  |  |
| `postage_stamp_frame` | Static Frame | int | `1` | -2147483648 to 2147483647 |  |  |
| `lifetimeStart` | Lifetime Start | int | `0` | -2147483648 to 2147483647 |  |  |
| `lifetimeEnd` | Lifetime End | int | `100` | -2147483648 to 2147483647 |  |  |
| `useLifetime` | Use Lifetime | boolean | `false` |  |  |  |
| `cached` | Cached | boolean | `false` |  |  |  |
| `bookmark` | Bookmark | boolean | `false` |  |  |  |
| `dope_sheet` | Dope Sheet | boolean | `false` |  |  |  |
| `clone_group` | Clone Group | string |  |  |  |  |
| `link_source` | Link Source | string |  |  |  |  |
| `link_overrides` | Link Overrides | string |  |  |  |  |
| `split_views` | Split Views | string |  |  |  |  |

## Examples

Open these from **Help › Examples…**, or from the **?** menu in this node's Properties panel.

- **DeepMerge four deep passes** (`examples/deep/deep_merge.oink`): Weta's forest scene as four deep passes (Balls, Ground, Leaves, Trunks). DeepMerge combines the samples by depth, so the passes hold each other out with no mattes; DeepToImage flattens the result. Compare with LowResLeftView/composited.exr, the flat reference.


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Sources: opencomp_core/nodes/deep/deep_nodes.py, opencomp_electron/src/components/properties/knobSchema.ts, opencomp_core/nk/mapping.py