Basemaps has two main components to its configuration
- Imagery - List of tiffs that make up a imagery set
- TileSet - List of imagery or vector layers that make up a output layer.
The configuration can be stored as individual AWS DynamoDB objects or can be stored as a bundled JSON object.
The configuration is generally generated directly from the source tiffs and associated STAC metadata using the @basemaps/cli import process, with LINZ's specific configuration being stored in linz/basemaps-config.
This allows the configuration objects to be somewhat short, below is a snippet from the aerial tile set configuration which layers 100+ aerial imagery layers together.
{
// Raster or Vector layer
"type": "raster",
// all id's are prefixed by type eg 'ts_' is TileSet
"id": "ts_aerial",
// Human friendly name
"title": "Aerial Imagery Basemap",
"category": "Basemaps",
// If there is no data create a background color as hex RGBA
"background": "dce9edff",
"layers": [
{
// Source location for EPSG:2193 Imagery
"2193": "s3://linz-basemaps/2193/gebco_2020_Nztm2000Quad_305-75m/01F1BFJN8R8P7BXN3XTHC5MT5G",
// Source location for EPSG:3857 Imagery
"3857": "s3://linz-basemaps/3857/gebco_2020_305-75m/01EDMTM3P563P06TWYQAZRA9F6",
// url/slug friendly name of the imagery set
"name": "gebco-2020-305.75m",
// At what level should the imagery be turned off
"maxZoom": 15,
// Human friendly name for the imagery
"title": "GEBCO Gridded Bathymetry (2020)",
"category": "Bathymetry"
},
...
]
}When this configuration is imported it will list all of the source locations looking for collection.json and *.tiff|*.tif files.
Configuration can be stored as single JSON object in s3 and then passed directly to the basemaps service with ?config=s3://linz-basemaps/config/config-latest.json.gz this allows basemaps to preview a configuration before being deployed.