# Moon Base Zero — asset attribution

Terrain assets are derived from **public-domain NASA data**; the 3D models are a
mix of **NASA 3D Resources** and third-party models (noted below).

## 3D models (`models/`)

Except where noted, every GLB is from **NASA 3D Resources**
(<https://science.nasa.gov/3d-resources/>, mirrored at
<https://github.com/nasa/NASA-3D-Resources>). NASA 3D Resources assets are free
and without copyright; see the
[NASA Images and Media Usage Guidelines](https://www.nasa.gov/nasa-brand-center/images-and-media/).
Models marked "optimized" were compressed with `@gltf-transform` (no
remodeling) to keep web payloads small.

| File | Source model | Used for |
|---|---|---|
| `bluemoon-mk1.glb` (optimized) | Purchased "Blue Moon MK1 lunar lander" (Sketchfab Standard License, FAB conversion). Textures resized to 2048² WebP and Draco-compressed, 40 MB → 1.7 MB; no remodeling. | Blue Moon MK1 cargo lander |
| `perseverance-rover.glb` | Mars 2020 Perseverance Rover (NASA) | NASA LTV (rover stand-in) |

Blue Moon MK1 is the purchased model above. Starship HLS, MK2 and the other
commercial vehicles have no photoreal file; they are
procedural geometry in `ProjectModel.tsx`, and the LTV still uses the
Perseverance rover as a stand-in.

## Earth backdrop (`earth/`)

The fixed Earth prop rendered by `EarthGlobe.tsx` (day map, night lights, and
cloud layer). All three are NASA public-domain source imagery (Blue Marble
day composite, Black Marble / DMSP city-lights composite, and a MODIS cloud
composite), redistributed as processed textures in the MIT-licensed three.js
project's own example assets and mirrored here rather than re-fetched from
NASA's own (much larger, unprocessed) originals.

| File | Source | Used for |
|---|---|---|
| `earth-day.jpg` | `three.js/examples/textures/planets/earth_atmos_2048.jpg` | Day-side albedo map |
| `earth-lights.png` | `three.js/examples/textures/planets/earth_lights_2048.png` | Night-side city lights (emissive map) |
| `earth-clouds.png` | `three.js/examples/textures/planets/earth_clouds_1024.png` | Cloud layer |

Source: <https://github.com/mrdoob/three.js> (MIT license), `examples/textures/planets/`.

## Connecting Ridge terrain (`southpole/`)

Baked from the **PGDA "Improved LOLA Elevation Maps for South Pole Landing
Sites" Site01 DEM** — a 5 m/px, 16×16 km polar stereographic elevation model
of the **Shackleton–de Gerlache connecting ridge** (the Artemis-era landing
zone), produced from Lunar Orbiter Laser Altimeter data by NASA GSFC.
Source: [PGDA product 78](https://pgda.gsfc.nasa.gov/products/78)
(`Site01_final_adj_5mpp_surf.tif`, MOON_ME frame).

| File | Derivation |
|---|---|
| `height_rg.png` | 16-bit heights split across the R (high byte) / G (low byte) channels, normalized to the patch's height range. True vertical scale (no exaggeration) — the moonbase on it is 1:1. |

Heights are the only shipped asset, and everything visible about the ground is
derived from them: the renderer builds surface normals from this file at load
and shades them with the regolith BRDF (`ui/lib/lunar-atlas/regolith.ts`).

There used to be a second file here, `albedo.jpg`, a synthesized regolith albedo
with hillshade lighting baked in. It was removed rather than regenerated, for a
reason that belongs in an attribution file specifically: most of its apparent
realism came from a randomly generated power-law crater population, and at the
top of that distribution it was painting hundreds of craters over 100 m across
onto a real, published, checkable DEM of a real place. Synthetic detail below the
source's resolution is honest gap-filling. Synthetic landforms at that scale are
not, and they have no business in an asset presented as LOLA-derived. Detail finer
than the DEM is now generated procedurally at runtime, where it is unambiguously
not data.

Rebuild with `ui/scripts/build-southpole-assets.py` (documents the exact
pipeline and the constants shared with `ui/lib/lunar-atlas/southpole.ts`).

- **Elevation:** LOLA site DEMs — Barker, M. K., et al. (2021), "Improved
  LOLA Elevation Maps for South Pole Landing Sites: Error Estimates and Their
  Impact on Illumination Conditions", Planetary & Space Science 203, 105119.
- **License:** NASA data is generally not copyrighted and is free to use (see
  [NASA media usage guidelines](https://www.nasa.gov/nasa-brand-center/images-and-media/)).