To construct a CesiumTerrainProvider, call
A CesiumTerrainProvider.fromIonAssetId
or CesiumTerrainProvider.fromUrl
. Do not call the constructor directly.
TerrainProvider
that accesses terrain data in a Cesium terrain format.
Terrain formats can be one of the following:
参数名称 | 类型 | 描述信息 |
---|---|---|
options |
CesiumTerrainProvider.ConstructorOptions | 可选 An object describing initialization options |
- createWorldTerrain
- CesiumTerrainProvider.fromUrl
- CesiumTerrainProvider.fromIonAssetId
- TerrainProvider
使用示例:
// Create Arctic DEM terrain with normals.
try {
const viewer = new Cesium.Viewer("cesiumContainer", {
terrainProvider: await Cesium.CesiumTerrainProvider.fromIonAssetId(3956, {
requestVertexNormals: true
})
});
} catch (error) {
console.log(error);
}
参考:
成员(属性)
readonly availability : TileAvailability
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. Note that this reflects tiles that are known to be available currently.
Additional tiles may be discovered to be available in the future, e.g. if availability information
exists deeper in the tree rather than it all being discoverable at the root. However, a tile that
is available now will not become unavailable in the future.
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 metadata.
Gets a value indicating whether or not the requested tiles include vertex normals.
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.
Boolean flag that indicates if the client should request metadata from the server.
Metadata is appended to the standard tile mesh data only if the client requests the metadata and
if the server provides a metadata.
Boolean flag that indicates if the client should request vertex normals from the server.
Vertex normals data is appended to the standard tile mesh data only if the client requests the vertex normals and
if the server provides vertex normals.
Boolean flag that indicates if the client should request a watermask from the server.
Watermask data is appended to the standard tile mesh data only if the client requests the watermask and
if the server provides a watermask.
readonly tilingScheme : GeographicTilingScheme
Gets the tiling scheme used by this provider.
方法
static Cesium.CesiumTerrainProvider.fromIonAssetId(assetId, options) → Promise.<CesiumTerrainProvider>
Creates a
TerrainProvider
from a Cesium ion asset ID that accesses terrain data in a Cesium terrain format
Terrain formats can be one of the following:
参数名称 | 类型 | 描述信息 |
---|---|---|
assetId |
number | The Cesium ion asset id. |
options |
CesiumTerrainProvider.ConstructorOptions | 可选 An object describing initialization options. |
返回值:
Throws:
-
RuntimeError : layer.json does not specify a format
-
RuntimeError : layer.json specifies an unknown format
-
RuntimeError : layer.json specifies an unsupported quantized-mesh version
-
RuntimeError : layer.json does not specify a tiles property, or specifies an empty array
-
RuntimeError : layer.json does not specify any tile URL templates
使用示例:
// Create Arctic DEM terrain with normals.
try {
const viewer = new Cesium.Viewer("cesiumContainer", {
terrainProvider: await Cesium.CesiumTerrainProvider.fromIonAssetId(3956, {
requestVertexNormals: true
})
});
} catch (error) {
console.log(error);
}
static Cesium.CesiumTerrainProvider.fromUrl(url, options) → Promise.<CesiumTerrainProvider>
Creates a
TerrainProvider
that accesses terrain data in a Cesium terrain format.
Terrain formats can be one of the following:
参数名称 | 类型 | 描述信息 |
---|---|---|
url |
Resource | String | Promise.<Resource> | Promise.<String> | The URL of the Cesium terrain server. |
options |
CesiumTerrainProvider.ConstructorOptions | 可选 An object describing initialization options. |
返回值:
Throws:
-
RuntimeError : layer.json does not specify a format
-
RuntimeError : layer.json specifies an unknown format
-
RuntimeError : layer.json specifies an unsupported quantized-mesh version
-
RuntimeError : layer.json does not specify a tiles property, or specifies an empty array
-
RuntimeError : layer.json does not specify any tile URL templates
使用示例:
// Create Arctic DEM terrain with normals.
try {
const viewer = new Cesium.Viewer("cesiumContainer", {
terrainProvider: await Cesium.CesiumTerrainProvider.fromUrl(
Cesium.IonResource.fromAssetId(3956), {
requestVertexNormals: true
})
});
} catch (error) {
console.log(error);
}
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.
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 or availability is unknown, otherwise true or false.
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
Requests the geometry for a given tile. The result must include terrain data and
may optionally include a water mask and an indication of which 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
Initialization options for the CesiumTerrainProvider constructor
属性:
属性名称 | 类型 | 可选 | 默认值 | 描述信息 |
---|---|---|---|---|
requestVertexNormals |
boolean |
<可选> |
false | Flag that indicates if the client should request additional lighting information from the server, in the form of per vertex normals if available. |
requestWaterMask |
boolean |
<可选> |
false | Flag that indicates if the client should request per tile water masks from the server, if available. |
requestMetadata |
boolean |
<可选> |
true | Flag that indicates if the client should request per tile metadata from the server, if available. |
ellipsoid |
Ellipsoid |
<可选> |
Ellipsoid.default | The ellipsoid. If not specified, the default ellipsoid is used. |
credit |
Credit | string |
<可选> |
A credit for the data source, which is displayed on the canvas. |