Elevation data (DEM) sources and formats

3D terrain and hillshade are both driven by a digital elevation model (DEM) - a raster of height values for the Earth's surface. Terrain and hillshade each have their own DEM source setting in the World Effects dialog, so you can shade the relief from one model and raise the map with another.

Sources

Source What it is
Mapterhorn The built-in global DEM. Nothing to configure, works everywhere.
Icon Map Catalog A ready-built high-resolution elevation dataset picked from the catalog - no URL to paste, attribution applied automatically. Premium datasets are billed by usage.
Custom URL Your own DEM, hosted anywhere reachable over HTTPS. Choose the encoding to match your data (see below).
OneLake file A DEM stored in your own item's Files. The picker lists .pmtiles, .tif and .tiff.

Elevation datasets in the catalog include, for example, the United Kingdom at 1 m, the Netherlands, Switzerland and Luxembourg at 0.5 m, and a global ocean and land model that lets you dive below sea level. Browse the catalog with the DEM picker to see everything currently published.

Supported formats

Format Choose Notes
Mapzen Terrarium RGB tiles Encoding: Terrarium (RGB) A {z}/{x}/{y} PNG tile template. The most common open terrain-tile encoding.
Mapbox Terrain-RGB tiles Encoding: Mapbox Terrain-RGB A {z}/{x}/{y} PNG tile template. All Icon Map Catalog elevation datasets use this encoding.
PMTiles archive Paste a pmtiles://… URL, or pick a .pmtiles file from OneLake A single-file tile archive holding either of the encodings above. Read by range request, so only the tiles in view are fetched.
ArcGIS elevation service Encoding: ArcGIS elevation service The URL of an ArcGIS ImageServer whose service data type is elevation. Each tile is requested as a 32-bit float GeoTIFF through exportImage and converted for display, so the full precision of the source is preserved. The service must expose the Image capability and allow cross-origin requests.
Greyscale relief tiles Encoding: Greyscale relief tiles A {z}/{x}/{y} template of 8-bit greyscale tiles, where grey level maps linearly onto elevation. Enter the Min and Max elevation of the data. This is an approximation - 8 bits over a 1,000 m range is about 4 m per step - so use it only where no better encoding exists. Greyscale tiles that are a shaded relief picture rather than height values will not produce correct terrain, however the settings are adjusted.
GeoTIFF / Cloud Optimized GeoTIFF Encoding: GeoTIFF / COG elevation A single elevation raster in any EPSG coordinate reference system - for example Environment Agency LiDAR in British National Grid, or a USGS or Copernicus COG. Read by HTTP range request and reprojected in the browser as you pan. Paste a URL ending .tif / .tiff, or pick the file from OneLake.

Sizes and limits

  • Tile size. 256 or 512 pixel tiles are both supported and detected from the source. Mapterhorn serves 512 px tiles; catalog elevation datasets are 256 px. ArcGIS, greyscale and GeoTIFF sources are converted to 256 px tiles internally.
  • Detail zoom. Set Max detail zoom to cap the zoom level at which the DEM is sampled - above it the map smoothly interpolates the last level rather than inventing detail. Left blank, the default is zoom 18 for ArcGIS and GeoTIFF sources and zoom 14 for greyscale.
  • Elevation range. Heights from -11,000 m to 9,000 m are carried; values outside that range, and any no-data pixels, are treated as sea level.
  • Dataset size. There is no practical limit for tiled sources. Tiles and PMTiles archives are fetched on demand, a few tiles at a time - the elevation datasets we publish ourselves range from about 1.5 GB to 164 GB and stream without special handling.
  • Single GeoTIFF files. Also read on demand rather than downloaded whole, so size is not the constraint - internal structure is. A file with internal tiling and overviews (a true Cloud Optimized GeoTIFF) performs best. A plain GeoTIFF without overviews costs a one-off decode the first time it is drawn zoomed out - around 15 seconds for a 5,000 x 5,000 pixel float raster, then a fraction of a second per tile after that. If your data comes without overviews, gdal_translate -of COG converts it in one step.
  • Hosting and CORS. Tile templates and PMTiles archives on hosts that do not allow cross-origin requests are fetched automatically through the built-in proxy. GeoTIFF, COG and ArcGIS sources are read directly by the browser, so those hosts must allow cross-origin range requests themselves. Files in your own OneLake always work.

Format references

The formats above are open specifications published by others:

Next steps

  • World Effects - turn on 3D terrain and hillshade and set the exaggeration and lighting.
  • Icon Map Catalog - browse the published datasets, including elevation.