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:
|
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
readonly credit : Credit
Gets the credit to display when this terrain provider is active. Typically this is used to credit
the source of the terrain.
readonly errorEvent : Event
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.
readonly tilingScheme : TilingScheme
Gets the tiling scheme used by this provider.
Gets the number of columns per heightmap tile.
Methods
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.
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.
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.