docsby gkjohnson

TerrainRGBMeshPlugin

Generates terrain tiles from raster Terrain-RGB elevation tiles. Each elevation texture is shared by multiple layers of sub tiles that displace a smooth surface mesh on the GPU with a subview of the texture, so elevation scale and seam updates only require texture changes.

[!NOTE] Enabling frustum culling on the tile meshes is not supported since the geometry bounds do not include the gpu displacement. Culling is handled by the tile traversal.

[!NOTE] Debug bounding volume visualizations, such as those from DebugTilesPlugin, may not display correctly after changing the height scale since they are not rebuilt when the tile bounding volumes update.

Building terrain from Terrain-RGB encoded elevation tiles
Data courtesy of Mapterhorn, Esri World Imagery
On this page

Methods

constructor

new TerrainRGBMeshPlugin(
	options?: {
		// XYZ url template, e.g. `.../{z}/{x}/{y}.png`.
		url: string,

		// Source tile pixel size.
		tileDimension: number = 256,

		// Highest zoom level the source provides.
		maxZoom: number = 15,

		// Factor applied to the meter elevations. A pure vertical exaggeration on the ellipsoid, while planar projections need the meters-to-world conversion folded in. Can be adjusted dynamically.
		heightScale: number = 1,

		// Overlay used to texture the tiles when `applyOverlayTexture` is enabled.
		overlay: ImageOverlay = null,

		// Whether to apply the overlay texture.
		applyOverlayTexture: boolean = false,

		// Render the tiles without lighting or terrain normals.
		unlit: boolean = false,

		// Display the tiles on the ellipsoid, on a plane in the source projection, or on a plane in the named projection scheme.
		projection: 'ellipsoid' | 'source' | string = 'ellipsoid',

		// Snap poles to ±90° lat.
		endCaps: boolean = true,

		// Apply recommended TilesRenderer settings.
		useRecommendedSettings: boolean = true
	}
)

sampleCartographicElevation

sampleCartographicElevation(
	// Latitude in radians.
	lat: number,

	// Longitude in radians.
	lon: number
): number | null

Samples the loaded elevation data at the given cartographic point using the finest loaded texture covering it. The height scale is applied so the result matches the displaced surface.