Greece map -- data sources and attribution ========================================== Built by mapgen.py from configs/greece.json on 2026-09-28. Every input is public and needs no account or key. Datasets used ------------- Borders Natural Earth 1:10m Cultural Vectors, version 5.1.1. PUBLIC DOMAIN (https://www.naturalearthdata.com, 'Made with Natural Earth'; no permission needed, attribution appreciated). Downloaded from https://naciscdn.org/naturalearth/10m/cultural/.zip ne_10m_admin_0_countries: GRC is the land (74 polygon parts); the neighbours (Albania, Bulgaria, Kosovo, North Macedonia, Turkey) are sea, and split the sea with it for islands. ne_10m_admin_1_states_provinces: the nations' regions. ne_10m_populated_places: the nations' spawn points. Lakes Natural Earth 1:10m Physical Vectors (ne_10m_lakes, ne_10m_lakes_europe), public domain, https://naciscdn.org/naturalearth/10m/physical/.zip Elevation AWS Open Data Terrain Tiles (Mapzen/Tilezen 'terrarium' PNG tiles), zoom 10 (563 tiles) for the relief and zoom 12 (2303 tiles) along the coast for the coastline, https://s3.amazonaws.com/elevation-tiles-prod/terrarium/{z}/{x}/{y}.png (registry: https://registry.opendata.aws/terrain-tiles/). A compilation of public DEMs; the ones covering this area and their required credit: * SRTM and GMTED2010 terrain data courtesy of the U.S. Geological Survey (NASA/USGS, public domain); * Global ETOPO1 terrain data U.S. National Oceanic and Atmospheric Administration (public domain; the sea floor, used only to tell sea from land); * Europe terrain data produced using Copernicus data and information funded by the European Union - EU-DEM layers. Full attribution list: https://github.com/tilezen/joerd/blob/master/docs/attribution.md Geometry -------- Projection EPSG:2100 (pyproj 3.8.0); conformal and metric, so no aspect correction is used. Grid 2176 x 2224 tiles at 360.7 m/tile (784.9 x 802.2 km) Origin tile (x,y) covers E = 110092.2 + 360.7*x, N = 4639297.9 - 360.7*y (bounding box of the land plus 15 km of sea). Latitude row 0 = 41.9 N, last row = 34.7 N (crates/of_app/src/view.rs latitude_range: "greece" => (41.9, 34.7)), measured at the centre column. Coastline the Natural Earth outline refined by the DEM: a tile is land when at least half of it is DEM land (terrarium elevation > 0 m; zoom 12 pixels of ~30 m, because at zoom 11 and below the tiles fill the sea near the coast from ETOPO1's 1.8 km cells and close narrow straits such as Salamis), restricted to the sea nearer to Greece than to any neighbour and within 40 km of its coast (this adds the small islands Natural Earth 1:10m leaves out); more than 3 km inside the Natural Earth outline a tile is always land. Land borders are exactly Natural Earth's. Everything outside the border is water (the Switzerland rule). Elevation curve magnitude = round(curve(u)), clamped 0..31, where e is the tile's mean elevation (zoom 10 tiles, averaged into the tile) and u = e - 0.3*(e - gaussian(e, sigma = 2 tiles)), the blur taken over land only so the sea does not drag the coast down. The curve is the auto_bands fit (--tune): half the land below 360 m is Plains, 17% above 891 m is Mountain, and the top segment runs to the highest ground so peaks are not clamped. Measured alternatives: Switzerland's own recipe (120 m per step, +2 mask) makes Greece 90% Plains with a slope of 0.46; a linear step fine enough for its bands (40 m) gives a slope of 0.77 to 1.15 and 22 to 37% rock. The mask is a slight softening (-0.3) instead of Switzerland's sharpening (+2): Greek tiles are twice as wide (361 m vs 175 m), so the renderer's fixed 9-tile smoothing removes less real relief here. curve: piecewise-linear [[0.0, 0.0], [360.0, 9.5], [891.0, 19.5], [2476.0, 31.0]]. Result: mean slope 0.631 magnitude steps/tile, 9.4% rock, bands 50.0% Plains / 33.0% Highland / 17.0% Mountain, mean magnitude 10.26 (Switzerland 0.62 / 8.8% / 51-34-15 / 11.10, Britannia 0.67 / 12.4% / 39-53-9 / 10.12, measured the same way by validate_map.py). map4x / map16x: slope 0.971 / 1.382, rock 22.83% / 38.71% (a coarser tile spans more ground; Switzerland 0.81 / 1.02, Britannia 0.93 / 1.25, Europe 1.18 / 1.53). Water magnitude OpenFront's convention: min(ceil(d/2), 31), d = Manhattan distance from the shoreline water. Lake policy Natural Earth lakes inside the land are lakes; a lake that reaches the border joins the sea outside it and is ocean. A lake under 40 tiles at full res (5.2 km2), 10 at 4x or 3 at 16x is filled back to land at the ground height. River policy none: rivers are not carved (at this scale they are narrower than a tile). Island policy land bodies under 2 tiles at full resolution are dropped; every island that survives the downsample is kept at 4x and 16x. Downsampling map4x / map16x: plurality vote of each 2x2 block (a 2-2 tie goes to the side with the larger sub-tile land fraction); sea cut off by the vote is reconnected along its real channel; then the small-body cleanup above. 16x is built from 4x. Carved channel tiles: 4x 1, 16x 4. Climate (climate.bin) --------------------- Source Beck, H.E., N.E. Zimmermann, T.R. McVicar, N. Vergopolan, A. Berg, E.F. Wood: Present and future Koppen-Geiger climate classification maps at 1-km resolution, Scientific Data 5, 180214 (2018), doi:10.1038/sdata.2018.214. Data: figshare, doi:10.6084/m9.figshare.6396959 (Beck_KG_V1.zip, no login), Beck_KG_V1_present_0p0083.tif (present day, 1980-2016, ~1 km). Licence CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/): attribution required; the classes were turned into moisture values and reprojected (changes made). Grid the map16x grid, 544 x 556: one byte per 16x tile, 0 = driest, 255 = wettest, on the terrain shader's own moisture scale (x 255). Method each Koppen class -> a moisture (table below); reprojected with the map's projection, each 16x tile the area average of the 1 km cells in it; the sea and the neighbours (water on this map) take the nearest own land's value; Gaussian smoothing, sigma 8 km (5.5 tiles of 1.44 km). Classes BWh, BWk 0.06; BSh, BSk 0.28; Csa 0.34; Dsa 0.40; Csb, Csc, Dsb 0.46; Dsc, Dsd 0.48; Aw, ET, EF 0.50; Cwa, Cwb, Cwc, Dwa, Dfa 0.52; Cfb, Cfc, Dwb, Dwc, Dwd, Dfb 0.53; Dfc, Dfd 0.58; Cfa 0.60; Am 0.66; Af 0.76. The shader's temperate ladder: desert under 0.22, steppe to 0.33, grass to 0.56, forest above; in hot country savanna from 0.24, grass from 0.45, jungle above 0.56. Tundra and snow come from the temperature. Land the largest classes by 16x land tile: Csa 62%, BSk 17%, Csb 10%, Dsb 5%, Dfb 3%, Cfa 2%. As the temperate ladder reads it: desert 0.0%, steppe 17.5%, grass 81.5%, forest 1.0% (before the shader's noise, heat and altitude). Colour (colour.jpg) ------------------- Source the ESA WorldCover Sentinel-2 median L2A (RGBNIR) composite of 2021, v200 (the ESA WorldCover project; made by the ESA WorldCover consortium from Copernicus Sentinel-2 data), its true-colour bands B04, B03 and B02 (the NIR band not used): one cloud-optimised GeoTIFF a 1 x 1 degree cell in the open-data bucket https://esa-worldcover-s2.s3.eu-central-1.amazonaws.com/rgbnir/2021//ESA_WorldCover_10m_2021_v200__S2RGBNIR.tif, read at its overview level 4 (750 pixels a degree), only that level, by range requests (Front+ 1.0.9 step s02, 16 October 2026; every piece in mapdata/DOWNLOADS.txt). 53 cells used; of the cells under the land and its one-tile ring 0 the bucket does not have (open sea) and 0 are missing. Licence CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/); the terms: https://esa-worldcover.org/en/data-access ("provided free of charge, without restriction of use"). Attribution © ESA WorldCover project / Contains modified Copernicus Sentinel data (2021) processed by ESA WorldCover consortium Grid the full map grid, 2176 x 2224: RGB, 8 bits a channel, sRGB, one texel a tile (0.361 km in the map's projection); JPEG, quality 90. Changed the source pixels averaged in blocks of 1 x 1 (2.4 x 3.1 of them a texel, north-south x east-west, at the land's middle), reprojected with the map's projection onto its grid, each texel the area average of the pixels in it in linear light (reflectance); water left out by the map's own land mask, and within 2 tiles of the map's own water also the imagery's own water (dark and blue pixels); clouds left out under the game's snow line (mean reflectance over 1.50 and spread under 0.05 of the mean; 0 texels touched); the 8,496 land texels with no data or mostly left-out pixels filled from the land round them, every texel that is not land from the nearest land texel; the tone: 1.6 x reflectance, to the power 0.9, highlights rolled off above 0.6, the colours 1.45 x as far from grey, exposure 1. Built 2026-10-16 (mapgen_imagery.py). Land mean colour 108, 108, 80 (sRGB), spread 23 / 15 / 17; 0 of 1,015,500 land texels had no source pixel with data (0.00%). Game the terrain shader takes the land's base colour from this instead of its biome palette, under its own light, relief shading, territory tint, borders, haze, snow and water, while the Realistic look is on (the Settings switch is the default for every map; each map can change it on the Singleplayer page; off, it draws the palette). Land a match raises where this map has sea keeps the palette. Nations ------- One per region; the spawn is the region's largest Natural Earth populated place (else the admin-1 label point), snapped to the nearest tile that is land at all three resolutions, in the same region and on the same landmass (coast at 16x avoided). Attica gr-i (1015, 1207) Athens (largest Natural Earth populated place, pop 3,242,000) Central Macedonia gr-b ( 818, 370) Thessaloniki (largest Natural Earth populated place, pop 828,000) Western Greece gr-g ( 532, 1125) Patra (largest Natural Earth populated place, pop 163,360) Crete gr-m (1365, 2024) Iraklio (largest Natural Earth populated place, pop 137,154) Thessaly gr-e ( 704, 697) Larissa (largest Natural Earth populated place, pop 128,758) Epirus gr-d ( 331, 676) Ioanina (largest Natural Earth populated place, pop 86,304) Central Greece gr-h ( 986, 1060) Chalkida (largest Natural Earth populated place, pop 71,842) Peloponnese gr-j ( 616, 1493) Kalamata (largest Natural Earth populated place, pop 71,823) East Macedonia and Thrace gr-a (1174, 295) Kavala (largest Natural Earth populated place, pop 59,240) South Aegean gr-l (2127, 1664) Rodos (largest Natural Earth populated place, pop 56,969) Ionian Islands gr-f ( 103, 683) Kerkira (largest Natural Earth populated place, pop 38,517) North Aegean gr-k (1691, 852) Mitilini (largest Natural Earth populated place, pop 29,328) Western Macedonia gr-c ( 481, 460) admin-1 label point of West Macedonia (no Natural Earth populated place in the region) Mount Athos (Natural Earth GR-69, the autonomous monastic state) is folded into Central Macedonia. Natural Earth 1:10m has no Kastellorizo; the map ends east of Rhodes. Flags are ISO 3166-2:GR codes (gr-i = Attica; Natural Earth files it as GR-A1).