ScreenKey
Green / blue screen keyer with the controls of a Keylight-style keyer: screen colour, gain and balance, clip black / white, shrink / grow, softness, despill with bias, and inside / outside masks.
Green / blue screen keyer with the controls of a Keylight-style keyer: screen colour, gain and balance, clip black / white, shrink / grow, softness, despill with bias, and inside / outside masks. Keylight and Primatte nodes in a .nk open as ScreenKey.
| Node | ScreenKey |
|---|---|
| Menu | Keyer › ScreenKey |
| Names in each format | |
| .oink comp (JSON) | "type": "OC_N_screenkey" |
| .nk script | ScreenKey, also imports OFXuk.co.thefoundry.keylight.keylight_v201, OFXuk.co.thefoundry.keylight.keylight_v200, Keylight (how .nk import works) |
| Python | nuke.createNode("ScreenKey") |
| Assistant (MCP) | create_node(type="ScreenKey") |
| Tab search | screenkey, or its initials sk |
Usage
- Open the panel and Ctrl+Shift+drag over the screen in the Viewer (Ctrl+click picks one pixel). The colour is taken from the Source input.
- View Status: white is solid, black clear, grey partial. Raise screen gain or clip black to clean the background, lower clip white to fill the foreground.
- Connect a garbage matte to OutM and a holdout to InM. The output is premultiplied (screen subtracted, spill removed); merge it over the background, or connect the background to Bg.
Inputs and outputs
| Port | Name | Type |
|---|---|---|
| input 0 | Source | image |
| input 1 | Bg | image |
| input 2 | InM | image |
| input 3 | OutM | image |
| output 0 | Image | image |
Knobs
Panel tab Screenkey, in panel order.
| Knob | Label | Type | Default | Range / values | .nk knob | Description |
|---|---|---|---|---|---|---|
view | View | menu | final | final (Final Result), intermediate (Intermediate Result), screen_matte (Screen Matte), status (Status), source (Source) | Final Result, Intermediate Result (unpremultiplied), Screen Matte, Status, Source. | |
screen_colour | Screen Colour | colour ×3 | 0, 0, 0 | 0 to 1 | the picked screen colour (black, the default, keys nothing). | |
screen_gain | Screen Gain | float | 1 | 0 to 2 | more gain removes more screen. | |
screen_balance | Screen Balance | float | 0.5 | 0 to 1 | weight of the first of the two other channels in the colour difference. | |
pre_blur | Pre-blur | float | 0 | 0 to 10 | blurs the source for the matte only (grain, compression). | |
edge_refine | Edge Refine | bool | true | solves the edge alpha against the foreground colour next to it. | ||
clip_black | Clip Black | float | 0 | 0 to 1 | ||
clip_white | Clip White | float | 1 | 0 to 1 | ||
shrink_grow | Shrink/Grow | float | 0 | -20 to 20 | erode (negative) or dilate (positive) the matte, in pixels. | |
softness | Softness | float | 0 | 0 to 20 | blur of the matte, in pixels. | |
despill | Despill | float | 1 | 0 to 1 | how much of the leftover spill to remove. | |
despill_bias | Despill Bias | colour ×3 | 0.5, 0.5, 0.5 | 0 to 1 | a colour the despill must leave unchanged (e.g. a skin tone). | |
premultiply | Premultiply | bool | true | premultiplied output (off = unpremultiplied colour with the alpha). |
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.
- Greenscreen: ScreenKey, Despill, comp over a sky (
examples/keying/greenscreen_key_despill.oink): Tears of Steel plate 08_3a (CC BY 3.0, Blender Foundation, mango.blender.org): an actor on a green screen that falls off towards the frame edges. ScreenKey pulls the key from a screen colour picked over the open screen (Ctrl+click or Ctrl+Shift+drag in the Viewer with its panel open), with screen gain 1.1 and clip black / white 0.1 / 0.9 for the uneven screen; its own despill is off so the Despill node (average) does it. The premultiplied result goes over a Poly Haven sky (CC0) reformatted to the plate. The same chain ships as the Keying ToolSet.