TerrainProvider
查阅Mars3D API

new Cesium.TerrainProvider()
engine/Source/Core/TerrainProvider.js 19

Provides terrain or other geometry for the surface of an ellipsoid. The surface geometry is organized into a pyramid of tiles according to a TilingScheme. This type describes an interface and is not intended to be instantiated directly.
参考:

成员(属性)

static Cesium.TerrainProvider.heightmapTerrainQuality : number
engine/Source/Core/TerrainProvider.js 352

Specifies the quality of terrain created from heightmaps. A value of 1.0 will ensure that adjacent heightmap vertices are separated by no more than Globe.maximumScreenSpaceError screen pixels and will probably go very slowly. A value of 0.5 will cut the estimated level zero geometric error in half, allowing twice the screen pixels between adjacent heightmap vertices and thus rendering more quickly.

readonly availability : TileAvailability
engine/Source/Core/TerrainProvider.js 87

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/TerrainProvider.js 43

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.<TerrainProvider.ErrorEvent>
engine/Source/Core/TerrainProvider.js 32

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/TerrainProvider.js 75

Gets a value indicating whether or not the requested tiles include vertex normals.

readonly hasWaterMask : boolean
engine/Source/Core/TerrainProvider.js 65

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.

readonly tilingScheme : TilingScheme
engine/Source/Core/TerrainProvider.js 53

Gets the tiling scheme used by the provider.

方法

static Cesium.TerrainProvider.getEstimatedLevelZeroGeometricErrorForAHeightmap(ellipsoid, tileImageWidth, numberOfTilesAtLevelZero) → number
engine/Source/Core/TerrainProvider.js 362

Determines an appropriate geometric error estimate when the geometry comes from a heightmap.
参数名称 类型 描述信息
ellipsoid Ellipsoid The ellipsoid to which the terrain is attached.
tileImageWidth number The width, in pixels, of the heightmap associated with a single tile.
numberOfTilesAtLevelZero number The number of tiles in the horizontal direction at tile level zero.
返回值:
An estimated geometric error.

static Cesium.TerrainProvider.getRegularGridIndices(width, height) → Uint16Array|Uint32Array
engine/Source/Core/TerrainProvider.js 104

Gets a list of indices for a triangle mesh representing a regular grid. Calling this function multiple times with the same grid width and height returns the same list of indices. The total number of vertices must be less than or equal to 65536.
参数名称 类型 描述信息
width number The number of vertices in the regular grid in the horizontal direction.
height number The number of vertices in the regular grid in the vertical direction.
返回值:
The list of indices. Uint16Array gets returned for 64KB or less and Uint32Array for 4GB or less.

getLevelMaximumGeometricError(level) → number
engine/Source/Core/TerrainProvider.js 400

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/TerrainProvider.js 412

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 by the terrain provider, otherwise true or false.

loadTileDataAvailability(x, y, level) → undefined|Promise.<void>
engine/Source/Core/TerrainProvider.js 424

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/TerrainProvider.js 390

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

Cesium.TerrainProvider.ErrorEvent(err)
engine/Source/Core/TerrainProvider.js 428

A function that is called when an error occurs.
This:
参数名称 类型 描述信息
err TileProviderError An object holding details about the error that occurred.
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