Cesium API - TerrainData 中文文档

本文介绍下Cesium中 TerrainData API的详细使用说明。

TerrainData API 调用方法

new Cesium.TerrainData()

Core/TerrainData.js 13

单个瓦片的地形数据。此类型描述一个接口，不打算直接实例化。

参考：

成员变量

credits : Array.<Credit>

Core/TerrainData.js 23

这个瓦片的一个credits数组。

waterMask : Uint8Array|Image|Canvas

Core/TerrainData.js 32

包含在地形数据中的water mask，如果有的话。 Water mask是一个矩形Uint8Array或图像，其中值为255表示水，值为0表示陆地。 0到255之间的值也可以平滑地（smoothly）混合在陆地和水之间。

内置方法

interpolateHeight(rectangle, longitude, latitude) → Number

Core/TerrainData.js 48

计算指定经度和纬度处的地形高度。

Name	Type	Description
`rectangle`	Rectangle	The rectangle covered by this terrain data.
`longitude`	Number	经度（以弧度为单位）
`latitude`	Number	纬度（以弧度为单位）

返回值：

指定位置的地形高度。 If the position is outside the rectangle, this method will extrapolate the height, which is likely to be wildly incorrect for positions far outside the rectangle.

isChildAvailable(thisX, thisY, childX, childY) → Boolean

Core/TerrainData.js 63

Determines if a given child tile is available, based on the TerrainData#childTileMask. The given child tile coordinates are assumed to be one of the four children of this tile. If non-child tile coordinates are given, the availability of the southeast child tile is returned.

Name	Type	Description
`thisX`	Number	The tile X coordinate of this (the parent) tile.
`thisY`	Number	The tile Y coordinate of this (the parent) tile.
`childX`	Number	The tile X coordinate of the child tile to check for availability.
`childY`	Number	The tile Y coordinate of the child tile to check for availability.

返回值：

True if the child tile is available; otherwise, false.

upsample(tilingScheme, thisX, thisY, thisLevel, descendantX, descendantY, descendantLevel) → Promise.<TerrainData>|undefined

Core/TerrainData.js 96

Upsamples this terrain data for use by a descendant tile.

Name	Type	Description
`tilingScheme`	TilingScheme	The tiling scheme of this terrain data.
`thisX`	Number	The X coordinate of this tile in the tiling scheme.
`thisY`	Number	The Y coordinate of this tile in the tiling scheme.
`thisLevel`	Number	The level of this tile in the tiling scheme.
`descendantX`	Number	The X coordinate within the tiling scheme of the descendant tile for which we are upsampling.
`descendantY`	Number	The Y coordinate within the tiling scheme of the descendant tile for which we are upsampling.
`descendantLevel`	Number	The level within the tiling scheme of the descendant tile for which we are upsampling.

返回值：

A promise for upsampled terrain data for the descendant tile, or undefined if too many asynchronous upsample operations are in progress and the request has been deferred.

wasCreatedByUpsampling() → Boolean

Core/TerrainData.js 107

Gets a value indicating whether or not this terrain data was created by upsampling lower resolution terrain data. If this value is false, the data was obtained from some other source, such as by downloading it from a remote server. This method should return true for instances returned from a call to TerrainData#upsample.

返回值：

True if this instance was created by upsampling; otherwise, false.