TerrainProvider

TerrainProvider

new

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.

See:
Source:

Members

<static>

Specifies the indices of the attributes of the terrain geometry.

<static>

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 CentralBody.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.

Methods

Gets the credit to display when this terrain provider is active. Typically this is used to credit the source of the terrain. This function should not be called before TerrainProvider#isReady returns true.

Returns:
Credit The credit, or undefined if no credit exists

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.

Returns:
Event The event.

Gets the maximum geometric error allowed in a tile at a given level. This function should not be called before TerrainProvider#isReady returns true.

Parameters:
Name Type Description
level Number The tile level for which to get the maximum geometric error.
Returns:
Number The maximum geometric error.

Gets the tiling scheme used by this provider. This function should not be called before TerrainProvider#isReady returns true.

Throws:
DeveloperError : getTilingScheme must not be called before the terrain provider is ready.
Returns:
GeographicTilingScheme The tiling scheme.
See:

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. This function should not be called before TerrainProvider#isReady returns true.

Returns:
Boolean True if the provider has a water mask; otherwise, false.

Gets a value indicating whether or not the provider is ready for use.

Returns:
Boolean True if the provider is ready to use; otherwise, false.

Requests the geometry for a given tile. This function should not be called before TerrainProvider#isReady returns true. The result must include terrain data and may optionally include a water mask and an indication of which child tiles are available.

Parameters:
Name Type Argument Default 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.
throttleRequests Boolean <optional>
true True if the number of simultaneous requests should be limited, or false if the request should be initiated regardless of the number of requests already in progress.
Returns:
Promise | TerrainData 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.

<static>

Creates a vertex array for wireframe rendering of a terrain tile.

Parameters:
Name Type Description
context Context The context in which to create the vertex array.
vertexArray VertexArray The existing, non-wireframe vertex array. The new vertex array will share vertex buffers with this existing one.
terrainMesh TerrainMesh The terrain mesh containing non-wireframe indices.
Returns:
VertexArray The vertex array for wireframe rendering.

<static>

Determines an appropriate geometric error estimate when the geometry comes from a heightmap.

Parameters:
Name Type Description
ellipsoid The ellipsoid to which the terrain is attached.
tileImageWidth The width, in pixels, of the heightmap associated with a single tile.
numberOfTilesAtLevelZero The number of tiles in the horizontal direction at tile level zero.
Returns:
Number An estimated geometric error.