# `TextureSpec.sizeM`

> 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 [`TextureSpec`](TextureSpec.md) · inherited by [`TextureSlot`](TextureSlot.md), [`TextureInput`](TextureInput.md) · stable · since 2.0.0

```ts
sizeM?: number | Point2;
```

Physical size one image covers, metres. The runtime computes [`scale`](TextureSpec.scale.md) as the slot's `uvMetres` ([`describe(node).manifest`](ModelDescription.manifest.md)) divided by `sizeM`, per axis; a shape with metre UVs counts as `uvMetres` 1. On a slot without `uvMetres` it records 'unsupported-spec' and leaves the placement as it was; a collection `model` item's GLB counts as one (its manifest's slots aren't read). `uvMetres` comes from the GLB's stamp, which the server doesn't write yet ([`ModelDescription.manifest`](ModelDescription.manifest.md)): until a GLB is stamped, write [`scale`](TextureSpec.scale.md) instead.

**Default:** undefined

## Generic-API test (spec 3.1)

| Rule | Result |
| --- | --- |
| 1. Neutral name | pass: `sizeM` names no product |
| 2. A precedent | pass: [glTF KHR_texture_transform](https://github.com/KhronosGroup/glTF/tree/main/extensions/2.0/Khronos/KHR_texture_transform) (row `K15`); [glTF 2.0 samplers](https://registry.khronos.org/glTF/specs/2.0/glTF-2.0.html#samplers) (row `K15`) |
| 3. Two apps, or labs | pass: 17 apps (ledger: app-04c2774145, app-0c773a4ee3, app-4762caacdc, app-4f16d2f6da, app-59c5b5751e, app-b362a81c85, app-b4ae2fce25, app-bcb7ef21da and 9 more; fleet cross-check: app-59c5b5751e, app-e61a0b42ad, app-f3598fad77) |
| 4. The cheaper fix first | decided per need in Appendix B: rows `K15` at tier stable (a member only where no rule, data, asset or app code serves the need) |