# Terrain artwork reuse notes

Reviewed 2026-10-27. This display derives a heightfield mesh from Mapzen/Tilezen Terrain Tiles samples and window used by the display. No proprietary poster art or user reference imagery is included.

Mapzen's terrain-specific rights page delegates to the provider's source-specific terms, reproduced in `PROVIDER-ATTRIBUTION.md` and `PROVIDER-SOURCES.md`. There is no single blanket Creative Commons license asserted for the entire mosaic. The documented global land inputs include SRTM and GMTED2010. Exact source rasters contributing to every pixel have not been resolved from the footprints database. The 13 delivered windows cover Ethiopia, Colombia, Kenya, Costa Rica, Guatemala, Rwanda, Burundi, Tanzania, China and Indonesia, outside the provider's documented regional Arctic/European/Canadian/Australian/New Zealand datasets. The expanded set retains the complete provider notices; no new blanket license or per-pixel source claim is made.

USGS states that its authored/produced data are in the U.S. public domain and requests proper credit. The provider documents SRTM as public-domain government data and includes the historical U.S. government notice reproduced in the full attribution document. Its GMTED2010 notice permits use without restriction, requests acknowledgement, and requires modifications to be described. The full provider attribution also retains all other named source notices, rather than discarding them based on an unverified per-pixel assumption. Preserve these notices, the original source links, and the modification statement when redistributing derived artwork or data. No government endorsement is claimed.

Modification statement: source RGB elevation tiles were bilinearly sampled into a local equirectangular grid. The unchanged samples are triangulated into an east/north/up heightfield. The sampled minimum is offset onto a schematic plinth and 5x vertical exaggeration is applied. An isometric orthographic projection displays real 100 m horizontal plane/triangle contour intersections. A depth buffer removes hidden lines; visible paths are simplified within 0.35 SVG pixels. Cut-wall hatching is schematic shading, not geological strata. No elevations are fabricated or manually repaired. Bounds, tile/source-grid hashes, sampling distances, projection, contour levels and artwork hashes are recorded in manifest.json. Printing/downloads remain inactive; previous exports and their bundled notices remain local historical artifacts.

Credit: Mapzen / Tilezen; SRTM and GMTED2010 terrain data courtesy of the U.S. Geological Survey. Global ETOPO1 terrain data: DOC/NOAA/NESDIS/NCEI, U.S. Department of Commerce. Government source material is not claimed as this project's proprietary work. Preserve the full terrain-specific provider notices and links with reused artwork or data.

Primary references:

- https://www.usgs.gov/information-policies-and-instructions/copyrights-and-credits
- https://mapzen.com/rights/
- https://github.com/tilezen/joerd/blob/master/docs/attribution.md
- https://github.com/tilezen/joerd/blob/master/docs/data-sources.md
- https://registry.opendata.aws/terrain-tiles/

This is a source-based permission/attribution review for the local prototype, not a legal opinion or a claim that every source pixel was traced individually. If the collection expands to another country or provider, review that area's source terms before redistributing derived artwork or data. Source data are provided as-is; derived terrain is unsuitable for navigation or engineering.