ElevationLayer
require(["esri/layers/ElevationLayer"], function(ElevationLayer) { /* code goes here */ });
esri/layers/ElevationLayer
ElevationLayer is a tile layer used for rendering elevations in SceneViews. A default world elevation layer can be added to the map by setting the map's ground property to world-elevation
.
Elevation layers are set in the layers property of a map's ground. They should not be added to the map's operational layers.
var elevLyr = new ElevationLayer({
// Custom elevation service
url: "https://sampleserver6.arcgisonline.com/arcgis/rest/services/Elevation/MtBaldy_Elevation/ImageServer"
});
// Add elevation layer to the map's ground.
map.ground.layers.add(elevLyr);
If the service is requested from a different domain, a CORS enabled server or a proxy is required.
- See also:
Constructors
- new ElevationLayer(properties)
- Parameter:properties Objectoptional
See the properties for a list of all the properties that may be passed into the constructor.
Property Overview
Name | Type | Summary | Class | |
---|---|---|---|---|
String | The copyright text as defined by the service. more details | more details | ElevationLayer | |
String | The name of the class. more details | more details | Accessor | |
Extent | The full extent of the layer. more details | more details | Layer | |
String | The unique ID assigned to the layer. more details | more details | Layer | |
String | Indicates how the layer should display in the LayerList widget. more details | more details | Layer | |
Boolean | Indicates whether the layer's resources have loaded. more details | more details | Layer | |
Error | The Error object returned if an error occurred while loading. more details | more details | Layer | |
String | Represents the status of a load operation. more details | more details | Layer | |
Object[] | A list of warnings which occurred while loading. more details | more details | Layer | |
PortalItem | The portal item from which the layer is loaded. more details | more details | ElevationLayer | |
Object | The image service's metadata JSON exposed by the ArcGIS REST API. more details | more details | ElevationLayer | |
SpatialReference | The spatial reference of the layer as defined by the service. more details | more details | ElevationLayer | |
TileInfo | Contains information about the tiling scheme for the layer. more details | more details | ElevationLayer | |
String | The title of the layer used to identify it in places such as the Legend and LayerList widgets. more details | more details | ElevationLayer | |
String | For ElevationLayer the type is always "elevation". more details | more details | ElevationLayer | |
String | URL pointing to the Elevation layer resource on an ArcGIS Image Server. more details | more details | ElevationLayer | |
Boolean | Indicates if the layer is visible in the View. more details | more details | Layer |
Property Details
- copyright String
The copyright text as defined by the service.
- Since: ArcGIS API for JavaScript 4.7
The name of the class. The declared class name is formatted as
esri.folder.className
.
The full extent of the layer. By default, this is worldwide. This property may be used to set the extent of the view to match a layer's extent so that its features appear to fill the view. See the sample snippet below.
Example:// Once the layer loads, set the view's extent to the layer's fullextent layer.when(function(){ view.extent = layer.fullExtent; });
The unique ID assigned to the layer. If not set by the developer, it is automatically generated when the layer is loaded.
Indicates how the layer should display in the LayerList widget. The possible values are listed below.
Value Description show The layer is visible in the table of contents. hide The layer is hidden in the table of contents. hide-children If the layer is a GroupLayer, BuildingSceneLayer, KMLLayer, MapImageLayer, TileLayer or WMSLayer, hide the children layers from the table of contents. Possible Values:"show"|"hide"|"hide-children"
- Default Value:show
Indicates whether the layer's resources have loaded. When
true
, all the properties of the object can be accessed.- Default Value:false
The Error object returned if an error occurred while loading.
- Default Value:null
Represents the status of a load operation.
Value Description not-loaded The object's resources have not loaded. loading The object's resources are currently loading. loaded The object's resources have loaded without errors. failed The object's resources failed to load. See loadError for more details. Possible Values:"not-loaded"|"loading"|"failed"|"loaded"
- Default Value:not-loaded
A list of warnings which occurred while loading.
- portalItem PortalItem
The portal item from which the layer is loaded. If the portal item references a Feature Service or Scene Service, then you can specify a single layer to load with the layerId property.
Examples:// while this example uses FeatureLayer, this same pattern can be // used for other layers that may be loaded from portalItem ids var lyr = new FeatureLayer({ portalItem: { // autocasts as new PortalItem() id: "caa9bd9da1f4487cb4989824053bb847" } // the first layer in the service is returned });
// set hostname when using an on-premise portal (default is ArcGIS Online) // esriConfig.portalUrl = "http://myHostName.esri.com/arcgis"; // while this example uses FeatureLayer, this same pattern can be // used for SceneLayers var lyr = new FeatureLayer({ portalItem: { // autocasts as new PortalItem() id: "8d26f04f31f642b6828b7023b84c2188" }, // loads the third item in the given feature service layerId: 2 });
- sourceJSON ObjectSince: ArcGIS API for JavaScript 4.13
The image service's metadata JSON exposed by the ArcGIS REST API. While most commonly used properties are exposed on the ElevationLayer class directly, this property gives access to all information returned by the elevation image service. This property is useful if working in an application built using an older version of the API which requires access to elevation image service properties from a more recent version.
- spatialReference SpatialReferencereadonly
The spatial reference of the layer as defined by the service.
- tileInfo TileInfo
Contains information about the tiling scheme for the layer.
- title String
The title of the layer used to identify it in places such as the Legend and LayerList widgets.
When loading a layer by service url, the title is derived from the service name. When the layer is loaded from a portal item, the title of the portal item will be used instead. Finally, if a layer is loaded as part of a webmap or a webscene, then the title of the layer as stored in the webmap/webscene will be used.
- type Stringreadonly
For ElevationLayer the type is always "elevation".
- url String
URL pointing to the Elevation layer resource on an ArcGIS Image Server.
Example:url: "http://elevation3d.arcgis.com/arcgis/rest/services/WorldElevation3D/Terrain3D/ImageServer"
Indicates if the layer is visible in the View. When
false
, the layer may still be added to a Map instance that is referenced in a view, but its features will not be visible in the view.- Default Value:true
Example:// The layer is no longer visible in the view layer.visible = false;
Method Overview
Name | Return Type | Summary | Class | |
---|---|---|---|---|
Cancels a load() operation if it is already in progress. more details | more details | Layer | ||
Promise<ElevationSampler> | Creates an elevation sampler for the given Extent by querying the service layer for elevation data and caching it so values may be sampled quickly afterwards. more details | more details | ElevationLayer | |
Promise<LayerView> | Called by the views, such as MapView and SceneView, when the layer is added to the Map.layers collection and a layer view must be created for it. more details | more details | Layer | |
Boolean | Emits an event on the instance. more details | more details | Layer | |
Promise<Object> | Fetches custom attribution data for the layer when it becomes available. more details | more details | Layer | |
Promise<ElevationTileData> | Requests a tile from the service and decodes the data into a linear array of elevation values. more details | more details | ElevationLayer | |
String | This method returns a URL to a tile for a given level, row and column. more details | more details | ElevationLayer | |
Boolean | Indicates whether there is an event listener on the instance that matches the provided event name. more details | more details | Layer | |
Boolean |
| more details | Layer | |
Boolean |
| more details | Layer | |
Boolean |
| more details | Layer | |
Promise | Loads the resources referenced by this class. more details | more details | Layer | |
Object | Registers an event handler on the instance. more details | more details | Layer | |
Promise<ElevationQueryResult> | Queries the service layer for elevation values for the given geometry. more details | more details | ElevationLayer | |
Promise |
| more details | Layer |
Method Details
- createElevationSampler(extent, options){Promise<ElevationSampler>}Since: ArcGIS API for JavaScript 4.7
Creates an elevation sampler for the given Extent by querying the service layer for elevation data and caching it so values may be sampled quickly afterwards. The resolution of the cached data can be set using the
demResolution
option. In many cases,auto
demResolution can be used to get high quality elevation samples without the need to know exactly where the data in the service is located. This is particularly useful for services which combine elevation data from many sources (such as the world elevation service). If more control, or higher quality samples are required, use eitherfinest-contiguous
or a fixed{number}
resolution.Parameters:Specification:extent ExtentThe extent for which to create the sampler.
options ObjectoptionalAdditional query options. See the table below.
Specification:optional Default Value: autoControls the horizontal resolution (cell size) in meters from which elevation data is sampled (defaults to
auto
). See ElevationLayer for more details.noDataValue NumberoptionalDefault Value: 0The value to use when there is no data available.
Returns:Type Description Promise<ElevationSampler> An elevation sampler.
Called by the views, such as MapView and SceneView, when the layer is added to the Map.layers collection and a layer view must be created for it. This method is used internally and there is no use case for invoking it directly.
Parameters:view *The parent view.
options ObjectoptionalAn object specifying additional options. See the object specification table below for the required properties of this object.
Specification:signal AbortSignaloptionalA signal to abort the creation of the layerview.
Returns:Type Description Promise<LayerView> Resolves with a LayerView instance. - See also:
- Since: ArcGIS API for JavaScript 4.5
Emits an event on the instance. This method should only be used when creating subclasses of this class.
Parameters:type StringThe name of the event.
event ObjectoptionalThe event payload.
Returns:Type Description Boolean true
if a listener was notified
Fetches custom attribution data for the layer when it becomes available.
Returns:Type Description Promise<Object> Resolves to an object containing custom attribution data for the layer.
- fetchTile(level, row, column, options){Promise<ElevationTileData>}
Requests a tile from the service and decodes the data into a linear array of elevation values.
The returned promise resolves with a plain object describing the obtained elevation data for the tile. The object has the following properties:
Property Type Description values Float32Array The elevation values contained in the tile. width number The number of elevation values in one row of the tile. height number The number of elevation values in one column of the tile. maxZError number The upper bound for the compression error on the elevation values. Parameters:Specification:level Numberthe tile level.
row Numberthe tile row.
column Numberthe tile column.
options ObjectoptionalOptional settings for the tile request.
Specification:noDataValue NumberoptionalThe value representing pixels in the tile that don't contain an elevation value.
signal AbortSignaloptionalAn AbortSignal to abort the request. If canceled, the promise will be rejected with an error named
AbortError
. See also AbortController.Returns:Type Description Promise<ElevationTileData> a Promise which resolves with elevation tile data.
- getTileUrl(level, row, col){String}
This method returns a URL to a tile for a given level, row and column.
Parameters:level NumberThe requested tile's level.
row NumberThe requested tile's row.
col NumberThe requested tile's column.
Returns:Type Description String Returns the tile URL.
Indicates whether there is an event listener on the instance that matches the provided event name.
Parameter:type StringThe name of the event.
Returns:Type Description Boolean Returns true if the class supports the input event.
isFulfilled()
may be used to verify if creating an instance of the class is fulfilled (either resolved or rejected). If it is fulfilled,true
will be returned.Returns:Type Description Boolean Indicates whether creating an instance of the class has been fulfilled (either resolved or rejected).
isRejected()
may be used to verify if creating an instance of the class is rejected. If it is rejected,true
will be returned.Returns:Type Description Boolean Indicates whether creating an instance of the class has been rejected.
isResolved()
may be used to verify if creating an instance of the class is resolved. If it is resolved,true
will be returned.Returns:Type Description Boolean Indicates whether creating an instance of the class has been resolved.
Loads the resources referenced by this class. This method automatically executes for a View and all of the resources it references in Map if the view is constructed with a map instance.
This method must be called by the developer when accessing a resource that will not be loaded in a View.
It's possible to provide a
signal
to stop being interested into aLoadable
instance load status. When the signal is aborted, the instance does not stop its loading process, only cancelLoad can abort it.Parameter:signal AbortSignaloptionalSignal object that can be used to abort the asynchronous task. The returned promise will be rejected with an Error named
AbortError
when an abort is signaled. See also AbortController for more information on how to construct a controller that can be used to deliver abort signals.Returns:Type Description Promise Resolves when the resources have loaded.
Registers an event handler on the instance. Call this method to hook an event with a listener.
Parameters:A event type, or an array of event types, to listen for.
listener FunctionThe function to call when the event is fired.
Returns:Type Description Object Returns an event handler with a remove()
method that can be called to stop listening for the event(s).Property Type Description remove Function When called, removes the listener from the event. Example:view.on("click", function(event){ // event is the event handle returned after the event fires. console.log(event.mapPoint); });
- queryElevation(geometry, options){Promise<ElevationQueryResult>}
Queries the service layer for elevation values for the given geometry. The returned result contains a copy of the geometry with z-values sampled from elevation data from the service. The resolution from which the elevation is queried can be set using the
demResolution
option. In many cases,auto
demResolution can be used to get high quality elevation samples without the need to know exactly where the data in the service is located. This is particularly useful for services which combine elevation data from many sources (such as the world elevation service). If more control, or higher quality samples are required, use eitherfinest-contiguous
or a fixed{number}
resolution.Parameters:Specification:geometry Point|Multipoint|PolylineThe geometry to use for sampling elevation data.
options ObjectoptionalAdditional query options. See the table below.
Specification:optional Default Value: autoControls the horizontal resolution (cell size) in meters from which elevation data is sampled (defaults to
auto
). See the table below for more details on the different settings.demResolution Description auto
Automatically chooses an appropriate resolution for each coordinate of the input geometry. The current implementation will try to use the finest available resolution given that the total required number of tile requests does not exceed a certain maximum amount (currently 20). Note that this may result in values being sampled from different resolutions. finest-contiguous
Sample elevation from the finest available resolution (cell size) across the entire geometry. {number}
Sample elevation from the resolution closest to the specified resolution (in meters). returnSampleInfo BooleanoptionalDefault Value: falseIndicates whether to return additional sample information for each coordinate.
noDataValue NumberoptionalDefault Value: 0The value to use when there is no data available.
signal AbortSignaloptionalAn AbortSignal to abort the request. If canceled, the promise will be rejected with an error named
AbortError
. See also AbortController.Returns:Type Description Promise<ElevationQueryResult> Resolves to an object with the sampled geometry, resolution information, and no data value. Example:require(["esri/layers/ElevationLayer", "esri/geometry/Multipoint"], function(ElevationLayer, Multipoint) { var url = "//elevation3d.arcgis.com/arcgis/rest/services/WorldElevation3D/Terrain3D/ImageServer/"; var layer = new ElevationLayer(url); // Various points across a ridge of the mount everest var points = [ [ 86.9252, 27.9883 ], [ 86.9265, 27.9894 ], [ 86.9292, 27.9923 ], [ 86.9324, 27.9960 ], [ 86.9359, 27.9992 ] ]; // Uses "auto" resolution by default layer.queryElevation(new Multipoint(points), { returnSampleInfo: true }) // Successfully sampled all points .then(function(result) { // Print result of each sampled point to the console result.geometry.points.forEach(function(point, index) { var elevation = Math.round(point[2]); var resolution = result.sampleInfo[index].demResolution; var coordinateText = "(" + point[0] + ", " + point[1] + ")"; var resolutionText = Math.round(resolution) + " meter resolution"; console.log("Sampled " + coordinateText + ": " + elevation + " at " + resolutionText); }); }) // Failed to sample (e.g. service unavailable) .catch(function(error) { console.error("Failed to query elevation:", error); }); });
- Since: ArcGIS API for JavaScript 4.6
when()
may be leveraged once an instance of the class is created. This method takes two input parameters: acallback
function and anerrback
function. Thecallback
executes when the instance of the class loads. Theerrback
executes if the instance of the class fails to load.Parameters:callback FunctionoptionalThe function to call when the promise resolves.
errback FunctionoptionalThe function to execute when the promise fails.
Returns:Type Description Promise Returns a new promise for the result of callback
that may be used to chain additional functions.Example:// Although this example uses MapView, any class instance that is a promise may use then() in the same way var view = new MapView(); view.when(function(){ // This function will execute once the promise is resolved }, function(error){ // This function will execute if the promise is rejected due to an error });
Type Definitions
- ElevationQueryResult
Object returned when queryElevation() promise resolves:
- Properties:
- geometry Point|Multipoint|Polyline
The geometry with sampled z-values.
optional Contains additional information about how the geometry was sampled. This property is present depending on whether the user set
options.returnSampleInfo = true
, for each coordinate in the geometry.- Specification:
- demResolution Number
The resolution at which the z-value was sampled. If no data was available for sampling for a given coordinate, the dem resolution value will be -1 for that coordinate.
noDataValue NumberThe value used when there is no data available.
Event Overview
Name | Type | Summary | Class | |
---|---|---|---|---|
{view: View,layerView: LayerView} | Fires after the layer's LayerView is created and rendered in a view. more details | more details | Layer | |
{view: View,error: Error} | Fires when an error emits during the creation of a LayerView after a layer has been added to the map. more details | more details | Layer | |
{view: View,layerView: LayerView} | Fires after the layer's LayerView is destroyed and no longer renders in a view. more details | more details | Layer |
Event Details
- layerview-createinherited
Fires after the layer's LayerView is created and rendered in a view.
- Properties:
- view View
The view in which the
layerView
was created.layerView LayerViewThe LayerView rendered in the view representing the layer in
layer
. - See also:
Example:// This function will fire each time a layer view is created for this // particular view. layer.on("layerview-create", function(event){ // The LayerView for the layer that emitted this event event.layerView; });
- layerview-create-errorinherited
Fires when an error emits during the creation of a LayerView after a layer has been added to the map.
- Properties:
- view View
The view that failed to create a layerview for the layer emitting this event.
error ErrorAn error object describing why the layer view failed to create.
- See also:
Example:// This function fires when an error occurs during the creation of the layer's layerview layer.on("layerview-create-error", function(event) { console.error("LayerView failed to create for layer with the id: ", layer.id, " in this view: ", event.view); });