Terrain module

The Terrain Module draws the relief of the map from the elevation data of the map style, in two ways that combine freely:

• Hillshade shades slopes with light and shadow, so hills, valleys and mountains read at any camera pitch.
• 3D elevation raises the map surface itself, which a pitched camera shows.

What this module owns: whether the hillshade is shown and how the shading looks — see Appearance below — and whether and how high the surface is raised. See Who owns what.

Initialization

import { TomTomMap, TerrainModule } from '@tomtom-org/maps-sdk/map';

const map = new TomTomMap({ mapLibre: { container: 'map' } });
const terrain = await TerrainModule.get(map, { hillshade: { visible: true }, elevation: { visible: true } });

• get() adds the terrain style part, which carries the elevation data, when the style lacks it.
• One terrain module per map: a second get() returns the same instance (style-owned modules).
• Without a configuration, get() changes nothing on screen: the hillshade is hidden until shown, and the surface stays as the style draws it. On a TomTom style that is flat, which is also where resetConfig() returns it; a terrain your own style or MapLibre code raised stays until you set elevation.visible.

Hillshade

Show the shading at initialization, or toggle it later:

const terrain = await TerrainModule.get(map, { hillshade: { visible: true } });

terrain.setHillshadeVisible(false);
terrain.isHillshadeVisible(); // false

isHillshadeVisible() reads the hillshade.visible setting back, false until something shows it.

Appearance

The shading's look sits beside visible under hillshade: method (one of hillshadeMethods), lightDirection, exaggeration, maxZoom, shadowColor, highlightColor, accentColor.

• They restyle the style's own hillshade layer, read its own value while unset, and show once the shading does.
• The standard styles ramp the shading's exaggeration to zero by zoom 13 and stop drawing it there, so at city zooms the shading shows nothing until both exaggeration and maxZoom are set.
• The light comes from 335° (north-west) by cartographic convention: relief lit from the south reads inside-out to most people.

import { setKnob, TerrainModule, terrainKnobCatalogue } from '@tomtom-org/maps-sdk/map';

const terrain = await TerrainModule.get(map, {
    // Keep the shading at every zoom:
    hillshade: { visible: true, method: 'multidirectional', exaggeration: 0.5, maxZoom: 22 },
});
setKnob(terrain, terrainKnobCatalogue, 'hillshade.shadowColor', '#3b2f2f');

3D elevation

Raise the surface with elevation.visible, and scale the relief with elevation.exaggeration (1 is true elevation). It scales height only; hillshade.exaggeration is the shading's strength and raises nothing:

import { setKnob, TerrainModule, terrainKnobCatalogue, TomTomMap } from '@tomtom-org/maps-sdk/map';

const map = new TomTomMap({
    mapLibre: { container: 'map', center: [7.66, 45.98], zoom: 12.5, pitch: 70, maxPitch: 85 },
});
const terrain = await TerrainModule.get(map, {
    elevation: { visible: true, exaggeration: 1.5 },
    hillshade: { visible: true },
});

setKnob(terrain, terrainKnobCatalogue, 'elevation.exaggeration', 2); // keeps the surface raised
terrain.setElevationVisible(false); // flat again, still shaded
terrain.isElevationVisible(); // false

isElevationVisible() reads the elevation.visible setting back. Until something sets it, it reports whether the map's own terrain raises the surface.

• Pitch the camera. Seen from straight above, a raised surface looks flat. MapLibre's default maxPitch is 60°; raise it to look along a valley.
• Combine it with the hillshade. The shading keeps a slope readable where the camera flattens it.
• The exaggeration is kept while elevation is off, so turning it back on restores the relief you had.
• The surface reads its own elevation source, TERRAIN_SOURCE_ID: a copy of the hillshade's HILLSHADE_SOURCE_ID that the module adds the first time elevation is enabled, since MapLibre draws both at a lower quality from one source. With both on, each elevation tile loads twice.

The 3D buildings of the base map (BaseMapModule layer group buildings3D) and the Landmarks 3D plugin stand on the raised surface.

Every setting as data

terrainKnobCatalogue lists every setting of the module's configuration as a knob, readable with no map loaded, so a UI can build its controls from it:

import { knobEntryOf, terrainKnobCatalogue } from '@tomtom-org/maps-sdk/map';

const exaggeration = knobEntryOf(terrainKnobCatalogue, 'elevation.exaggeration');
// { id: 'elevation.exaggeration', kind: 'number', description: '…', range: { min: 0.5, max: 3, step: 0.1, bounds: 'hard-min' }, default: 1 }

• terrainKnobIds lists the ids in catalogue order, TerrainKnobId is their union, and TerrainKnobValueOf<ID> the plain value one takes. setKnob sets one by id.
• getKnob reads a look knob left unset as the loaded style draws it, and getStyleColor reads the three colours by their map-wide ids, terrain.hillshade.shadowColor and its siblings, with or without the module.

Style changes

Both parts are map configuration, not style content: the module re-applies them on top of every style that setStyle loads, and a clean switch (resetState: true) turns them off. The sky above a tilted horizon is a styling knob, view.sky, which a style switch keeps too. The playground below switches styles under a tilted camera, with terrain and sky kept:

Events

The hillshade is a raster layer with no features to click or hover, so the module has lifecycle events only:

terrain.events.on('config-change', (config) => {
    console.log('Terrain config changed:', config);
});

API reference

For complete documentation of all Terrain Module properties, methods, and types, see the TerrainModule API Reference.

Related guides and examples

Related examples

• 3D terrain map - Terrain, hillshade, 3D buildings and Ljubljana Castle on its hill
• Hillshade - Hillshade shading on a flat map
• 3D terrain playground - Terrain, sky and exaggeration that outlive a style switch
• Globe and 3D terrain - A globe that zooms into 3D terrain
• Route fly-over playground - A camera flying a mountain route, clear of the relief it crosses

Related map modules

• Map styling - Sizes and map colours across the whole map, and the globe and sky for a tilted view
• Base map module - 3D buildings on top of the terrain