# Viewer

> Shows its input in the Viewer.

Shows its input in the Viewer. It has up to ten inputs, numbered 1-9 then 0; connecting the spare empty input adds the next one. Press 1 in the Node Graph to connect the selected node.

| Node | Viewer |
|---|---|
| Menu | Input/Output › Viewer |
| **Names in each format** | |
| .oink comp (JSON) | `"type": "OC_N_viewer"` |
| .nk script | `Viewer` ([how .nk import works](/docs/nuke-users/nk-import)) |
| Python | `nuke.createNode("Viewer")` |
| Assistant (MCP) | `create_node(type="Viewer")` |
| Tab search | `viewer` |

## Inputs and outputs

| Port | Name | Type |
|---|---|---|
| input 0 | 1 | image |

## Knobs

Knobs from the node definition (this node has no panel layout in the app yet).

| 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 |  |  |  |  |
| `active_input` | Active Input | int | `1` | 1 to 10 |  | Input shown (1-9, 10 = Nuke's input 0) |

## Examples

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

- **Read an EXR** (`examples/io/read_exr_basic.oink`): A single scanline EXR photo (openexr-images ScanLines/Desk.exr) read into scene-linear and shown in the Viewer. Start here: open the Read's properties to see the file, frame range and colour knobs.


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Sources: opencomp_core/nodes/viewer/viewer.py, opencomp_electron/src/components/properties/knobSchema.ts, opencomp_core/nodes/help/viewer.md, opencomp_core/nk/mapping.py