Ground | API Reference | ArcGIS Maps SDK for JavaScript 4.31

The Ground class contains properties that specify how the ground surface is displayed in a SceneView. It contains a layers property, which is a collection of ElevationLayer that defines the elevation or terrain of the map's surface.

On a Map instance, a default ground surface using the World Elevation Service can conveniently be initialized through the ground property:

let map = new Map({
  basemap: "topo-vector",
  ground: "world-elevation"
});

When terrain and bathymetry values are needed, the TopoBathy 3D Service can be used:

let map = new Map({
  basemap: "topo-vector",
  ground: "world-topobathymetry"
});

When no basemap is available, the Ground displays a grid by default:

ground-grid

That can be changed by setting a color on the surfaceColor property:

map.ground.surfaceColor = '#004c73';

ground-color

If the scene contains underground data, reduce the opacity of the ground to be able to see through the ground:

map.ground.opacity = 0.4;

See also

Constructors

Ground Constructor new Ground(properties)

Parameter

properties Object

optional

See the properties for a list of all the properties that may be passed into the constructor.

Property Overview

Any properties can be set, retrieved or listened to. See the Working with Properties topic.

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Type	Summary	Class
String	The name of the class.	Accessor
Collection<(ElevationLayer\|BaseElevationLayer)>	A collection of ElevationLayers that define the elevation or terrain that makes up the ground surface.	Ground
Error	The Error object returned if an error occurred while loading.	Ground
String	Represents the status of a load operation.	Ground
Object []	A list of warnings which occurred while loading.	Ground
Boolean	Indicates whether the instance has loaded.	Ground
Accessor	Specifies the user navigation constraints relative to the ground surface.	Ground
Number	Opacity of the ground, including surface default color and the basemap (without reference layers).	Ground
Color	The color of the ground surface, displayed underneath the basemap.	Ground

Property Details

declaredClass Inherited Property declaredClass Stringreadonly Inherited from Accessor Since: ArcGIS Maps SDK for JavaScript 4.7 Accessor since 4.0, declaredClass added at 4.7.

The name of the class. The declared class name is formatted as esri.folder.className.

layers Property layers Collection<(ElevationLayer|BaseElevationLayer)>

A collection of ElevationLayers that define the elevation or terrain that makes up the ground surface. When elevation layers are added to the ground, the topographical variations of the surface are rendered in 3D as they would appear in the real world.

elev-default

When the layers collection is empty, the ground surface is flat.

no-elev

Example

// Adds the esri world elevation service to the ground
let layer = new ElevationLayer({
  url: "//elevation3d.arcgis.com/arcgis/rest/services/WorldElevation3D/Terrain3D/ImageServer"
});
map.ground.layers.add(layer);

loadError Property loadError Errorreadonly

The Error object returned if an error occurred while loading.

Default Value:null

loadStatus Property loadStatus Stringreadonly

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"

loadWarnings Property loadWarnings Object[]readonly

A list of warnings which occurred while loading.

loaded Property loaded Booleanreadonly

Indicates whether the instance has loaded. When true, the properties of the object can be accessed. A Ground is considered loaded when its layers are fully created, but not yet loaded.

Default Value:false

navigationConstraint Property navigationConstraint Accessorautocast Since: ArcGIS Maps SDK for JavaScript 4.8 Ground since 4.0, navigationConstraint added at 4.8.

Specifies the user navigation constraints relative to the ground surface.

Property: type String

The type of the constraint. It can be one of the following:

Value Description

stay-above User can only navigate above ground surface

none User can navigate above and below the ground surface

Default value: stay-above

Possible Values:"stay-above"|"none"

opacity Property opacity Number Since: ArcGIS Maps SDK for JavaScript 4.8 Ground since 4.0, opacity added at 4.8.

Opacity of the ground, including surface default color and the basemap (without reference layers). This property can be used for a see-through ground effect.

Default Value:1

surfaceColor Property surfaceColor Colorautocast Autocasts from Object|Number []|String Since: ArcGIS Maps SDK for JavaScript 4.8 Ground since 4.0, surfaceColor added at 4.8.

The color of the ground surface, displayed underneath the basemap. If this is null, a grid is displayed instead. The alpha value in the color is ignored. Use the opacity property to control the opacity of the ground.

Default Value:null

Method Overview

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Return Type	Summary	Class
	Adds one or more handles which are to be tied to the lifecycle of the object.	Accessor
	Cancels a load() operation if it is already in progress.	Ground
Ground	Creates a deep clone of this object.	Ground
Promise<ElevationSampler>	Creates an elevation sampler for the given extent by querying the ground layers for elevation data and caching it so values may be sampled quickly afterwards.	Ground
	Destroys the ground and its layers.	Ground
*	Creates a new instance of this class and initializes it with values from a JSON object generated from an ArcGIS product.	Ground
Boolean	Returns true if a named group of handles exist.	Accessor
Boolean	`isFulfilled()` may be used to verify if creating an instance of the class is fulfilled (either resolved or rejected).	Ground
Boolean	`isRejected()` may be used to verify if creating an instance of the class is rejected.	Ground
Boolean	`isResolved()` may be used to verify if creating an instance of the class is resolved.	Ground
Promise	Loads the resources referenced by this class.	Ground
Promise<Ground>	Loads all the externally loadable resources associated with the ground.	Ground
Promise<ElevationQueryResult>	Query the ground layer services for elevation values for the given geometry.	Ground
	Removes a group of handles owned by the object.	Accessor
Object	Converts an instance of this class to its ArcGIS portal JSON representation.	Ground
Promise	`when()` may be leveraged once an instance of the class is created.	Ground

Method Details

addHandles Inherited Method addHandles(handleOrHandles, groupKey) Inherited from Accessor Since: ArcGIS Maps SDK for JavaScript 4.25 Accessor since 4.0, addHandles added at 4.25.

Adds one or more handles which are to be tied to the lifecycle of the object. The handles will be removed when the object is destroyed.

// Manually manage handles
const handle = reactiveUtils.when(
  () => !view.updating,
  () => {
    wkidSelect.disabled = false;
  },
  { once: true }
);

this.addHandles(handle);

// Destroy the object
this.destroy();

Parameters

handleOrHandles WatchHandle|WatchHandle []

Handles marked for removal once the object is destroyed.

groupKey *

optional

Key identifying the group to which the handles should be added. All the handles in the group can later be removed with Accessor.removeHandles(). If no key is provided the handles are added to a default group.

cancelLoad Method cancelLoad()

Cancels a load() operation if it is already in progress.

clone Method clone(){Ground}

Creates a deep clone of this object.

Returns

Type	Description
Ground	A deep clone of the Ground instance that invoked this method.

createElevationSampler Method createElevationSampler(extent, options){Promise<ElevationSampler>} Since: ArcGIS Maps SDK for JavaScript 4.7 Ground since 4.0, createElevationSampler added at 4.7.

Creates an elevation sampler for the given extent by querying the ground layers for elevation data and caching it so values may be sampled quickly afterwards. The sampler uses the elevation data from the first layer that has data available. For getting elevation data from a specific layer use ElevationLayer.createElevationSampler().

Parameters

Specification

extent Extent

The extent for which to create the sampler.

options Object

optional

Additional sampler options.

Specification

demResolution Number|String

optional

Default Value: auto

Controls the horizontal resolution (cell size) in meters from which elevation data is sampled (defaults to auto). See Ground for more details.

noDataValue Number

optional

Default Value: 0

The value to use when there is no data available.

signal AbortSignal

optional

An AbortSignal to abort the request. If canceled, the promise will be rejected with an error named AbortError. See also AbortController.

Returns

Type	Description
Promise<ElevationSampler>	An elevation sampler.

destroy Method destroy() Since: ArcGIS Maps SDK for JavaScript 4.17 Ground since 4.0, destroy added at 4.17.

Destroys the ground and its layers. These can no longer be used once the ground has been destroyed. To prevent the layers from being destroyed, remove them from the ground before calling destroy().

// prevent the layers from being destroyed by removing them from the ground
const layers = ground.layers.removeAll();

// destroy the ground and any remaining associated resources
ground.destroy();

See also

fromJSON Method fromJSON(json){*}static

Creates a new instance of this class and initializes it with values from a JSON object generated from an ArcGIS product. The object passed into the input json parameter often comes from a response to a query operation in the REST API or a toJSON() method from another ArcGIS product. See the Using fromJSON() topic in the Guide for details and examples of when and how to use this function.

Parameter

json Object

A JSON representation of the instance in the ArcGIS format. See the ArcGIS REST API documentation for examples of the structure of various input JSON objects.

Returns

Type	Description
*	Returns a new instance of this class.

hasHandles Inherited Method hasHandles(groupKey){Boolean} Inherited from Accessor Since: ArcGIS Maps SDK for JavaScript 4.25 Accessor since 4.0, hasHandles added at 4.25.

Returns true if a named group of handles exist.

Parameter

groupKey *

optional

A group key.

Returns

Type	Description
Boolean	Returns `true` if a named group of handles exist.

Example

// Remove a named group of handles if they exist.
if (obj.hasHandles("watch-view-updates")) {
  obj.removeHandles("watch-view-updates");
}

isFulfilled Method isFulfilled(){Boolean}

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 Method isRejected(){Boolean}

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 Method isResolved(){Boolean}

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.

load Method load(signal){Promise}

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.

The load() method only triggers the loading of the resource the first time it is called. The subsequent calls return the same promise.

It's possible to provide a signal to stop being interested into a Loadable instance load status. When the signal is aborted, the instance does not stop its loading process, only cancelLoad can abort it.

Parameter

signal AbortSignal

optional

Signal 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.

loadAll Method loadAll(){Promise<Ground>} Since: ArcGIS Maps SDK for JavaScript 4.9 Ground since 4.0, loadAll added at 4.9.

Loads all the externally loadable resources associated with the ground. For the ground this will load all the layers.

Returns

Type	Description
Promise<Ground>	Resolves when all the loadable resources have been loaded. Rejects if at least one of the loadable resources failed to load.

See also

load

Example

// Load all resources but ignore if one or more of them failed to load
ground.loadAll()
  .catch(function(error) {
    // Ignore any failed resources
  })
  .then(function() {
    console.log("All loaded");
  });

queryElevation Method queryElevation(geometry, options){Promise<ElevationQueryResult>}

Query the ground layer services 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 first layer that has data available. 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 either finest-contiguous or a fixed {number} resolution.

Parameters

Specification

geometry Point|Multipoint|Polyline

The geometry to sample.

options Object

optional

Additional query options.

Specification

demResolution Number|String

optional

Default Value: auto

Controls 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 Boolean

optional

Default Value: false

Indicates whether to return additional sample information for each sampled coordinate.

noDataValue Number

optional

Default Value: 0

The value that appears in the resulting geometry when there is no data available.

signal AbortSignal

optional

An 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/Map", "esri/geometry/Multipoint"], function(Map, Multipoint) {
  const map = new Map({
    ground: "world-elevation"
  });

  // Various points across a ridge of the mount everest
  const points = [
     [ 86.9252, 27.9883 ],
     [ 86.9265, 27.9894 ],
     [ 86.9292, 27.9923 ],
     [ 86.9324, 27.9960 ],
     [ 86.9359, 27.9992 ]
   ];

  map.ground.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) {
        const elevation = Math.round(point[2]);
        const resolution = result.sampleInfo[index].demResolution;

        const coordinateText = "(" + point[0] + ", " + point[1] + ")";
        const 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);
    });
});

removeHandles Inherited Method removeHandles(groupKey) Inherited from Accessor Since: ArcGIS Maps SDK for JavaScript 4.25 Accessor since 4.0, removeHandles added at 4.25.

Removes a group of handles owned by the object.

Parameter

groupKey *

optional

A group key or an array or collection of group keys to remove.

Example

obj.removeHandles(); // removes handles from default group

obj.removeHandles("handle-group");
obj.removeHandles("other-handle-group");

toJSON Method toJSON(){Object}

Converts an instance of this class to its ArcGIS portal JSON representation. See the Using fromJSON() guide topic for more information.

Returns

Type	Description
Object	The ArcGIS portal JSON representation of an instance of this class.

when Method when(callback, errback){Promise} Since: ArcGIS Maps SDK for JavaScript 4.6 Ground since 4.0, when added at 4.6.

when() may be leveraged once an instance of the class is created. This method takes two input parameters: a callback function and an errback function. The callback executes when the instance of the class loads. The errback executes if the instance of the class fails to load.

Parameters

callback Function

optional

The function to call when the promise resolves.

errback Function

optional

The 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 when() in the same way
let 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 Type Definition ElevationQueryResult

Object returned when queryElevation() promise resolves:

Properties

geometry Point|Multipoint|Polyline

The geometry with sampled z-values.

sampleInfo Object []

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.

source ElevationLayer

The elevation source from which the data for the corresponding coordinate was sampled.

noDataValue Number

The value used when there is no data available.