Base Theme

The Overture Base Theme provides additional context such as land and water that are critical to rendering a complete basemap. These features are currently derived from the Daylight Earth Tables schema and include the Daylight Coastlines.

Key Schema Design Choices

1. Basic classification of features into type, subType, and class where appropriate.
2. Parsing and normalization of common OSM tags, such as height and ele.
3. Extraction of consistent OSM tags, such as wikidata to top-level properties.
4. Direct pass-through of remaining relevant OSM tags.

Current Types:

1. land: Physical representations of land surfaces. Global land derived from the inverse of OSM Coastlines. Translates natural tags from OpenStreetMap.
2. landUse: Classifications of the human use of a section of land. Translates landuse from OpenStreetMap tag from OpenStreetMap.
3. water: Physical representations of inland and ocean marine surfaces. Translates natural and waterway tags from OpenStreetMap.