YULIN REGIONAL ATLAS — DATA AND SOFTWARE ATTRIBUTIONS

Map roads, waterways, water polygons, buildings, land use, places and boundaries:
© OpenStreetMap contributors, ODbL 1.0.
https://www.openstreetmap.org/copyright
https://opendatacommons.org/licenses/odbl/1-0/
Distributed through Geofabrik, Shaanxi snapshot 2026-09-05.
https://download.geofabrik.de/asia/china/shaanxi.html
Yulin city outline: OpenStreetMap relation 3016353, retrieved through Nominatim.
The derived OSM database in /data/atlas.json, /data/buildings.bin,
/data/landmarks.json, /data/urban-texture.bin, /data/territory.bin and
/data/landcover.bin is offered under ODbL 1.0. Landcover here is a sparse
rasterization of OSM tags, not a complete satellite-derived land-cover product.

Building binary format: little-endian float32, seven values per record:
[x_km, z_km, width_km, depth_km, angle_radians, height_m, height_source].
Source codes: 0 = OSM height tag (not independently surveyed),
1 = building levels × 3.1 m, 2 = default 7 m, 3 = illustrative urban texture.
Ordinary footprints have been reduced to oriented rectangles.
Urban texture is generated only within mapped urban land and represents
illustrative masses, not individual observed buildings.

Elevation: Copernicus DEM GLO-30 public distribution.
Produced using Copernicus WorldDEM-30 © DLR e.V. 2010-2014 and
© Airbus Defence and Space GmbH 2014-2018 provided under COPERNICUS
by the European Union and ESA; all rights reserved.
https://copernicus-dem-30m.s3.amazonaws.com/readme.html
https://dataspace.copernicus.eu/explore-data/data-collections/copernicus-contributing-missions/collections-description/COP-DEM
https://docs.sentinel-hub.com/api/latest/static/files/data/dem/resources/license/License-COPDEM-30.pdf
The source DSM was resampled for a regional display grid. Output heights remain
EGM2008-related orthometric metres. A local azimuthal equidistant projection is
used; x points east, z points south, in kilometres. The application subtracts
450 m as a numerical origin and applies a labelled display exaggeration.
No ellipsoid-height conversion is implied. Terrain.bin is little-endian float32.

This atlas is an independent implementation. It uses Three.js (MIT) for rendering.
The Seoul reference site's own application code and artwork are not included.
Source versions, checksums and transformation records: /data/provenance.json.

BUILDING SOURCE VALIDATION CANDIDATES (not loaded by the v0.2 atlas):
/data/building-candidates/ is a derived database offered under ODbL 1.0.
© Overture Maps Foundation and contributors; © OpenStreetMap contributors.
https://docs.overturemaps.org/guides/buildings/
https://docs.overturemaps.org/attribution/
https://opendatacommons.org/licenses/odbl/1-0/
Pinned Overture release: 2026-08-19.0.
All accepted additions in this extract originate from the East Asian buildings
dataset by Qian Shi, Jiajun Zhu, Zhengyu Liu, Haonan Guo, Mengxi Liu,
Zihong Liu and Xiaoping Liu: https://doi.org/10.5281/zenodo.8174931
Source IDs and attribution records are preserved per feature. The source's
release/update fields are not asserted to be imagery acquisition dates.
Footprint geometry does not establish measured building height or completeness.
Candidate height codes retain the meanings above; new footprints use an explicitly
labelled 7 m display default. Conflict features are kept in review.geojson, not
counted among accepted additions. See docs/BUILDING-COVERAGE.md for decisions.

V0.3 RUNTIME BUILDING TILES:
/data/cities-v3.json and /data/cities-v3/ derive from those accepted candidates
and are offered under ODbL 1.0 with the same attributions. 136,213 polygons are
available in twelve urban windows; the regional view still uses its earlier
simplification. Polygon and source-index order remain traceable to the candidate
database. At city scale, each footprint is approximated by its minimum rotated
rectangle; near views load complete polygon rings, including holes.
No new building-height evidence was added. 12,695 old schematic masses within
3 m of accepted footprints were removed; 8,999 independent schematic masses remain.
See docs/BUILDING-STREAM.md for binary formats, source flags, limits and checks.

V0.4 LAND COVER AND DISPLAY MATERIALS:
ESA WorldCover 2021 v200, Creative Commons Attribution 4.0 International.
https://doi.org/10.5281/zenodo.7254221
https://esa-worldcover.org/en/data-access
Required acknowledgement:
© ESA WorldCover project 2021 / Contains modified Copernicus Sentinel data
(2021) processed by ESA WorldCover consortium.
The five original 10 m classified GeoTIFFs are sampled at approximately 120 m
regionally and 30 m for urban material displays. Class samples, colour styling,
and the conservative OSM sand overlap mask are retained separately. Colours
are simplified and smoothed; they are not satellite photographs or a claim of
2026 land cover. Classified sample counts are not surveyed land-use areas.
The sand mask intersects WorldCover bare/sparse with OSM natural=sand polygons
from the 2026-09-05 snapshot; the OSM derivative retains ODbL attribution and
requirements. See /data/surface-v4.json for source URLs, identities and processing.
V0.4 continues to use the v0.3 building/road/water assets and source attributes.

V0.5 FULL-REGION TERRAIN STREAM:
/data/terrain-v5.json and /data/terrain-v5/ use the same 20 retained Copernicus
GLO-30 GeoTIFFs, with original pixel-centre bilinear sampling. Regional overview
spacing remains about 567 m; streamed medium/fine grids are about 142 m and 47 m.
The finer grid uses the original DEM, not interpolation of the overview grid.
produced using Copernicus WorldDEM-30 © DLR e.V. 2010-2014 and © Airbus Defence
and Space GmbH 2014-2018 provided under COPERNICUS by the European Union and ESA;
all rights reserved.
OSM road, water and boundary tiles derive from the same 2026-09-05 snapshot,
retain source IDs, and remain offered under ODbL 1.0. Mapped water polygons
take precedence over estimated-width waterway lines. Surfaces are draped for
display; bridges, water levels and individual building heights are not surveyed.
Pale terrain beyond the Yulin boundary is geographic context, not added territory.

v0.6 curated tour and two lake outlines (2026-09-07)
The camera views and captions are editorial choices. The retained 2026-09-05
OpenStreetMap PBF supplies complete outlines for way 136301890 (Hongjiannao)
and relation 5926990 (Gouchi), © OpenStreetMap contributors, ODbL 1.0.
Near terrain shows portions outside Yulin in pale context colour. Those portions
are not additional administrative territory. Draped water is a display treatment,
not a measured water level. No new building heights, DEM or imagery were acquired.
Source identity and processing: /data/tour-water-v6.json.

V0.8 OPT-IN BUILDING HEIGHT SAMPLES:
The default atlas continues to use its v0.4 manifest. With ?heights=cnbh,
/data/cities-v8-samples.json adds 2020 model-estimated heights to 16,068 existing
footprints in Yuyang, Shenmu and Suide. No footprint geometry is added or moved.
CNBH-10m by Wanben Wu, fixed Zenodo record 7923866 (2023 update), CC BY 4.0:
https://doi.org/10.5281/zenodo.7923866
https://creativecommons.org/licenses/by/4.0/
Wu et al. (2023), Remote Sensing of Environment 291, 113578:
https://doi.org/10.1016/j.rse.2023.113578
Changes: existing footprint overlap with original 10 m source pixels; positive
valid pixels weighted by intersection area; median height, rounded to 0.001 m
for numerical storage (not a 1 mm accuracy claim). Effective coverage <60%,
less than 3 valid pixels, less than 200 m2 valid overlap, or IQR >15 m retains
the prior default. All existing height and floor tags remain unchanged.
Source indices retain original height and per-building sampling evidence.
The modified footprint database retains ODbL 1.0 and all earlier attributions;
CNBH source material is separately attributed under CC BY 4.0. Neither source
endorses this atlas. Source snapshots and processing summary are available in
/data/height-audit-v8.json and /data/height-samples-v8.json.
In experimental YB03 building tiles only, low source bits 3 mean CNBH model
estimate, explicitly enabled by tile.heightModel='CNBH-10m-2020'. This does not
change code 3's illustrative meaning in the separate regional texture format.
Model heights are not surveyed, not current 2026 conditions, and not accepted
as a full twelve-city default. No GBA height or LoD1 data are included.