CustomHeightmapTerrainProvider

new Cesium.CustomHeightmapTerrainProvider(options)

A simple TerrainProvider that gets height values from a callback function. It can be used for procedurally generated terrain or as a way to load custom heightmap data without creating a subclass of TerrainProvider. There are some limitations such as no water mask, no vertex normals, and no availability, so a full-fledged TerrainProvider subclass is better suited for these more sophisticated use cases.
Name Type Description
options object Object with the following properties:
Name Type Description
callback CustomHeightmapTerrainProvider.GeometryCallback The callback function for requesting tile geometry.
width number The number of columns per heightmap tile.
height number The number of rows per heightmap tile.
tilingScheme TilingScheme optional The tiling scheme specifying how the ellipsoidal surface is broken into tiles. If this parameter is not provided, a GeographicTilingScheme is used.
ellipsoid Ellipsoid optional The ellipsoid. If the tilingScheme is specified, this parameter is ignored and the tiling scheme's ellipsoid is used instead. If neither parameter is specified, the WGS84 ellipsoid is used.
credit Credit | string optional A credit for the data source, which is displayed on the canvas.
Example:
const viewer = new Cesium.Viewer("cesiumContainer", {
  terrainProvider: new Cesium.CustomHeightmapTerrainProvider({
    width: 32,
    height: 32,
    callback: function (x, y, level) {
      return new Float32Array(32 * 32); // all zeros
    },
  }),
});
See:

Members

Gets the credit to display when this terrain provider is active. Typically this is used to credit the source of the terrain.
Gets an event that is raised when the terrain provider encounters an asynchronous error. By subscribing to the event, you will be notified of the error and can potentially recover from it. Event listeners are passed an instance of TileProviderError.
Gets a value indicating whether or not the requested tiles include vertex normals. Vertex normals are not supported by CustomHeightmapTerrainProvider, so the return value will always be false.
Gets a value indicating whether or not the provider includes a water mask. The water mask indicates which areas of the globe are water rather than land, so they can be rendered as a reflective surface with animated waves. Water mask is not supported by CustomHeightmapTerrainProvider, so the return value will always be false.
Gets the number of rows per heightmap tile.
Gets the tiling scheme used by this provider.
Gets the number of columns per heightmap tile.

Methods

getLevelMaximumGeometricError(level)number

Gets the maximum geometric error allowed in a tile at a given level.
Name Type Description
level number The tile level for which to get the maximum geometric error.
Returns:
The maximum geometric error.

getTileDataAvailable(x, y, level)boolean|undefined

Determines whether data for a tile is available to be loaded.
Name Type Description
x number The X coordinate of the tile for which to request geometry.
y number The Y coordinate of the tile for which to request geometry.
level number The level of the tile for which to request geometry.
Returns:
Undefined if not supported, otherwise true or false.

loadTileDataAvailability(x, y, level)undefined|Promise.<void>

Makes sure we load availability data for a tile
Name Type Description
x number The X coordinate of the tile for which to request geometry.
y number The Y coordinate of the tile for which to request geometry.
level number The level of the tile for which to request geometry.
Returns:
Undefined if nothing need to be loaded or a Promise that resolves when all required tiles are loaded

requestTileGeometry(x, y, level, request)Promise.<TerrainData>|undefined

Requests the geometry for a given tile. The result includes terrain data and indicates that all child tiles are available.
Name Type Description
x number The X coordinate of the tile for which to request geometry.
y number The Y coordinate of the tile for which to request geometry.
level number The level of the tile for which to request geometry.
request Request optional The request object. Intended for internal use only.
Returns:
A promise for the requested geometry. If this method returns undefined instead of a promise, it is an indication that too many requests are already pending and the request will be retried later.

Type Definitions

Cesium.CustomHeightmapTerrainProvider.GeometryCallback(x, y, level)Int8Array|Uint8Array|Int16Array|Uint16Array|Int32Array|Uint32Array|Float32Array|Float64Array|Array.<number>|Promise.<(Int8Array|Uint8Array|Int16Array|Uint16Array|Int32Array|Uint32Array|Float32Array|Float64Array|Array.<number>)>|undefined

Name Type Description
x number The X coordinate of the tile for which to request geometry.
y number The Y coordinate of the tile for which to request geometry.
level number The level of the tile for which to request geometry.
Returns:
An array or a promise to an array of heights in row-major order. If undefined, the globe will render the parent tile.
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