CustomHeightmapTerrainProvider
查阅Mars3D API

new Cesium.CustomHeightmapTerrainProvider(options)
engine/Source/Core/CustomHeightmapTerrainProvider.js 56

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.
参数名称 类型 描述信息
options object Object with the following properties:
参数名称 类型 默认值 描述信息
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 可选 The tiling scheme specifying how the ellipsoidal surface is broken into tiles. If this parameter is not provided, a GeographicTilingScheme is used.
ellipsoid Ellipsoid Ellipsoid.default 可选 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 default ellipsoid is used.
credit Credit | string 可选 A credit for the data source, which is displayed on the canvas.
使用示例:
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
    },
  }),
});
参考:

成员(属性)

readonly availability : TileAvailability
engine/Source/Core/CustomHeightmapTerrainProvider.js 172

Gets an object that can be used to determine availability of terrain from this provider, such as at points and in rectangles. This property may be undefined if availability information is not available.

readonly credit : Credit
engine/Source/Core/CustomHeightmapTerrainProvider.js 116

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
engine/Source/Core/CustomHeightmapTerrainProvider.js 103

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.

readonly hasVertexNormals : boolean
engine/Source/Core/CustomHeightmapTerrainProvider.js 158

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.

readonly hasWaterMask : boolean
engine/Source/Core/CustomHeightmapTerrainProvider.js 144

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.

readonly height : boolean
engine/Source/Core/CustomHeightmapTerrainProvider.js 196

Gets the number of rows per heightmap tile.

readonly tilingScheme : TilingScheme
engine/Source/Core/CustomHeightmapTerrainProvider.js 128

Gets the tiling scheme used by this provider.

readonly width : boolean
engine/Source/Core/CustomHeightmapTerrainProvider.js 184

Gets the number of columns per heightmap tile.

方法

getLevelMaximumGeometricError(level) → number
engine/Source/Core/CustomHeightmapTerrainProvider.js 251

Gets the maximum geometric error allowed in a tile at a given level.
参数名称 类型 描述信息
level number The tile level for which to get the maximum geometric error.
返回值:
The maximum geometric error.

getTileDataAvailable(x, y, level) → boolean|undefined
engine/Source/Core/CustomHeightmapTerrainProvider.js 264

Determines whether data for a tile is available to be loaded.
参数名称 类型 描述信息
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.
返回值:
Undefined if not supported, otherwise true or false.

loadTileDataAvailability(x, y, level) → undefined|Promise.<void>
engine/Source/Core/CustomHeightmapTerrainProvider.js 280

Makes sure we load availability data for a tile
参数名称 类型 描述信息
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.
返回值:
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
engine/Source/Core/CustomHeightmapTerrainProvider.js 216

Requests the geometry for a given tile. The result includes terrain data and indicates that all child tiles are available.
参数名称 类型 描述信息
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 可选 The request object. Intended for internal use only.
返回值:
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.

定义的类型

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
engine/Source/Core/CustomHeightmapTerrainProvider.js 11

参数名称 类型 描述信息
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.
返回值:
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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