3D terrain, draped over the map from an elevation source.

<HoloMap.Source.RasterDEM id="dem" tiles={@dem_tiles} encoding="terrarium" />
<HoloMap.Terrain source="dem" exaggeration={1.4} />

Terrain is a property of the map, not a layer. There is one, or there is none. Declaring the component turns it on; removing it from the template turns it off and the map flattens back out.

Props

Making terrain visible

Terrain does nothing at zero pitch, because a hill viewed from directly above still looks flat. Give the map a pitch, and usually let the user change it:

<HoloMap.Map cid="relief" style={@style} pitch={60} max_pitch={85}>
  <HoloMap.Source.RasterDEM id="dem" tiles={@dem_tiles} />
  <HoloMap.Terrain source="dem" exaggeration={1.4} />
  <HoloMap.Control.Navigation visualize_pitch />
</HoloMap.Map>

Exaggeration above roughly 2.0 reads as a video-game landscape rather than a map, which is a choice worth making deliberately.

Pair with HoloMap.Layer.Hillshade on the same DEM source for shaded relief, and HoloMap.Sky for an atmosphere at the horizon.