# `StageSettings.toneMapping`

> 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.

Property of [`StageSettings`](StageSettings.md) · stable · since 2.0.0 · called as `session.document.stage.toneMapping`

```ts
toneMapping?: 'product' | 'mood' | 'aces' | 'none' | {
  curve: readonly Point2[];
};
```

Named curves are formulas published with golden images. 'product': Khronos PBR Neutral.
'mood': AgX at −0.6 EV. 'aces': today's fleet look (ACES at −0.27 EV). `curve`: x is
scene-linear, y is display 0..1, linear before the output's sRGB encoding, as a named curve's.
At least 2 points, every x and y finite, x strictly increasing, else HoloInputError (the only checks); linear
between points, and flat beyond its ends: below the first point's x it holds that point's y,
above the last point's x the last point's y.

**Default:** the document's, else 'product', as 1.x's 'neutral' at exposure 1 (viewer/types.ts:735-736 at eb5ce2afe)

## Generic-API test (spec 3.1)

| Rule | Result |
| --- | --- |
| 1. Neutral name | pass: `toneMapping` names no product |
| 2. A precedent | pass: [Babylon.js ImageProcessingConfiguration (tone mapping, curves)](https://github.com/BabylonJS/Babylon.js/blob/master/packages/dev/core/src/Materials/imageProcessingConfiguration.ts) (row `K20`) |
| 3. Two apps, or labs | pass: 28 apps (ledger: app-59c5b5751e; fleet cross-check: app-04c2774145, app-0c773a4ee3, app-37356bf09f, app-378d190f1b, app-4762caacdc, app-4f16d2f6da, app-4fd23bc869, app-510d750508 and 20 more) |
| 4. The cheaper fix first | decided per need in Appendix B: rows `K20` at tier stable (a member only where no rule, data, asset or app code serves the need) |