# `BackgroundSpec`

> Contract 2.0.0 · package sha256 `a857eca95b35921109faf997094bb4192f12527d9d0fcd4be7e97f06425bad6e` · generated from `configurator-runtime.d.ts` by `services/onsite-scripter/scripts/build-contract-docs.mjs`; edit the source, not this file.

Type · `import type { BackgroundSpec } from '@holostep-configurators/runtime-client/contract';` · stable · since 2.0.0 · section 9. Stage

What is drawn behind the scene, in the colour pipeline. An image backdrop ('environment', `{ environment }` or a panorama) goes through `exposureEv` and the tone curve, as the lit scene does; a colour, a gradient and 'transparent' skip them, so a brand colour stays exact. 'environment' draws the stage's environment map, turned by its `rotationDeg` as the lighting is.

## Declaration

```ts
export type BackgroundSpec = ColorValue | 'environment' | 'transparent' | {
  gradient: ReadonlyArray<ColorValue | {
    color: ColorValue;
    at: number;
  }>;
  direction?: 'vertical' | 'horizontal' | 'radial';
} | {
  panorama: TextureInput;
  rotationDeg?: number;
  intensity?: number;
  mapping?: 'standard' | 'mirrored';
} | {
  environment: {
    intensity?: number;
    blur?: number;
  };
};
```

## Generic-API test (spec 3.1)

| Rule | Result |
| --- | --- |
| 1. Neutral name | pass: `BackgroundSpec` names no product |
| 2. A precedent | pass: [Babylon.js PhotoDome](https://github.com/BabylonJS/Babylon.js/blob/master/packages/dev/core/src/Helpers/photoDome.ts) (row `K22`) |
| 3. Two apps, or labs | pass: 22 apps (ledger: app-b4ae2fce25, app-ddfb017681; fleet cross-check: app-04c2774145, app-0c773a4ee3, app-37356bf09f, app-4762caacdc, app-4fd23bc869, app-822bb9d6aa, app-8675b3225c, app-b362a81c85 and 12 more) |
| 4. The cheaper fix first | decided per need in Appendix B: rows `K22` at tier app, stable (a member only where no rule, data, asset or app code serves the need) |