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LocationViewshed Class

LocationViewshed is an analysis object that renders a viewshed for a specified point location.
Inheritance Hierarchy

Namespace:  Esri.ArcGISRuntime.UI.GeoAnalysis
Assembly:  Esri.ArcGISRuntime (in Esri.ArcGISRuntime.dll) Version: 100.7.0.0
Syntax
C#
public sealed class LocationViewshed : Viewshed

The LocationViewshed type exposes the following members.

Constructors
  NameDescription
Public methodCode exampleLocationViewshed(Camera, Double, Double)
Initializes a new instance of the LocationViewshed class.
Public methodCode exampleLocationViewshed(MapPoint, Double, Double, Double, Double, Double, Double)
Initializes a new instance of the LocationViewshed class whose observer is defined using a point location.
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Properties
  NameDescription
Public propertyCode exampleHeading
Gets or sets the observer's heading.
Public propertyCode exampleHorizontalAngle
Gets or sets the horizontal angle of the observer's field of vision.
(Inherited from Viewshed.)
Public propertyCode exampleIsFrustumOutlineVisible
Gets or sets a value indicating whether or not the Viewshed frustum is visible.
(Inherited from Viewshed.)
Public propertyCode exampleIsVisible
Gets or sets a value indicating whether or not an Analysis is visible.
(Inherited from Analysis.)
Public propertyCode exampleLocation
Gets or sets the observer location of the viewshed.
Public propertyCode exampleMaxDistance
Gets or sets the maximum distance from the observer at which visibility will be evaluated.
(Inherited from Viewshed.)
Public propertyCode exampleMinDistance
Gets or sets the minimum distance from the observer at which visibility will be evaluated.
(Inherited from Viewshed.)
Public propertyCode examplePitch
Gets or sets the pitch of the observer's field of vision.
Public propertyCode exampleVerticalAngle
Gets or sets the vertical angle of the observer's field of vision.
(Inherited from Viewshed.)
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Methods
  NameDescription
Public methodCode exampleUpdateFromCamera
Updates the frustum of the viewshed using the properties of the supplied Camera.
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Remarks
LocationViewshed determines visible and non-visible areas in a GeoView for an observer defined with a map location.
Examples

Android

Example Name: ViewshedCamera

Analyze the viewshed for a camera. A viewshed shows the visible and obstructed areas from an observer's vantage point.

Code example screen shot.

C#
// Copyright 2017 Esri.
// 
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.
// You may obtain a copy of the License at: http://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an 
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific 
// language governing permissions and limitations under the License.

using Android.App;
using Android.OS;
using Android.Widget;
using Esri.ArcGISRuntime.Geometry;
using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.UI.Controls;
using Esri.ArcGISRuntime.UI.GeoAnalysis;
using System;

namespace ArcGISRuntime.Samples.ViewshedCamera
{
    [Activity (ConfigurationChanges=Android.Content.PM.ConfigChanges.Orientation | Android.Content.PM.ConfigChanges.ScreenSize)]
    [ArcGISRuntime.Samples.Shared.Attributes.Sample(
        "Viewshed for camera",
        "Analysis",
        "This sample demonstrates how to create a `LocationViewshed` to display interactive viewshed results in the scene view. The viewshed observer is defined by the scene view camera to evaluate visible and obstructed areas of the scene from that location.",
        "", "Featured")]
    public class ViewshedCamera : Activity
    {
        // Hold a reference to the scene view
        private SceneView _mySceneView;

        // URL for a scene service of buildings in Brest, France
        private string _buildingsServiceUrl = @"https://tiles.arcgis.com/tiles/P3ePLMYs2RVChkJx/arcgis/rest/services/Buildings_Brest/SceneServer/layers/0";

        // URL for an image service to use as an elevation source
        private string _elevationSourceUrl = @"https://scene.arcgis.com/arcgis/rest/services/BREST_DTM_1M/ImageServer";

        // Location viewshed analysis to show visible and obstructed areas from the camera
        private LocationViewshed _viewshedForCamera;

        protected override void OnCreate(Bundle bundle)
        {
            base.OnCreate(bundle);

            Title = "Viewshed camera";

            // Create the UI
            CreateLayout();

            // Create the Scene, basemap, camera, and location viewshed analysis
            Initialize();
        }

        private void Initialize()
        {
            // Create a new Scene with an imagery basemap
            Scene myScene = new Scene(Basemap.CreateImagery());

            // Create a scene layer to show buildings in the Scene
            ArcGISSceneLayer buildingsLayer = new ArcGISSceneLayer(new Uri(_buildingsServiceUrl));
            myScene.OperationalLayers.Add(buildingsLayer);

            // Create an elevation source for the Scene
            ArcGISTiledElevationSource elevationSrc = new ArcGISTiledElevationSource(new Uri(_elevationSourceUrl));
            myScene.BaseSurface.ElevationSources.Add(elevationSrc);

            // Add the Scene to the SceneView
            _mySceneView.Scene = myScene;

            // Set the viewpoint with a new camera focused on the castle in Brest
            Camera observerCamera = new Camera(new MapPoint(-4.49492, 48.3808, 48.2511, SpatialReferences.Wgs84), 344.488, 74.1212, 0.0);
            _mySceneView.SetViewpointCameraAsync(observerCamera);

            // Create a LocationViewshed analysis using the camera as the observer
            _viewshedForCamera = new LocationViewshed(observerCamera, 1, 1000);

            // Create an analysis overlay to contain the viewshed analysis results
            AnalysisOverlay viewshedOverlay = new AnalysisOverlay();

            // Add the location viewshed analysis to the analysis overlay, then add the overlay to the scene view
            viewshedOverlay.Analyses.Add(_viewshedForCamera);
            _mySceneView.AnalysisOverlays.Add(viewshedOverlay);
        }

        private void UpdateObserverWithCamera(object sender, EventArgs e)
        {
            // Use the current camera to update the observer for the location viewshed analysis
            _viewshedForCamera.UpdateFromCamera(_mySceneView.Camera);
        }

        private void CreateLayout()
        {
            // Create a new vertical layout for the app
            LinearLayout layout = new LinearLayout(this) { Orientation = Orientation.Vertical };

            // Create a button to update the viewshed using the current camera
            Button updateViewshedButton = new Button(this)
            {
                Text = "Viewshed from here"
            };
            updateViewshedButton.Click += UpdateObserverWithCamera;

            // Add the button and scene view to the layout
            layout.AddView(updateViewshedButton);
            _mySceneView = new SceneView(this);
            layout.AddView(_mySceneView);

            // Show the layout in the app
            SetContentView(layout);
        }
    }
}
Examples

Xamarin Forms Android

Example Name: ViewshedCamera

Analyze the viewshed for a camera. A viewshed shows the visible and obstructed areas from an observer's vantage point.

Code example screen shot.

C#
// Copyright 2017 Esri.
// 
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.
// You may obtain a copy of the License at: http://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an 
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific 
// language governing permissions and limitations under the License.

using Esri.ArcGISRuntime.Geometry;
using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.UI.GeoAnalysis;
using System;
using Xamarin.Forms;

namespace ArcGISRuntime.Samples.ViewshedCamera
{
    [ArcGISRuntime.Samples.Shared.Attributes.Sample(
        "Viewshed for camera",
        "Analysis",
        "This sample demonstrates how to create a `LocationViewshed` to display interactive viewshed results in the scene view. The viewshed observer is defined by the scene view camera to evaluate visible and obstructed areas of the scene from that location.",
        "", "Featured")]
    public partial class ViewshedCamera : ContentPage
    {
        // URL for a scene service of buildings in Brest, France
        private string _buildingsServiceUrl = @"https://tiles.arcgis.com/tiles/P3ePLMYs2RVChkJx/arcgis/rest/services/Buildings_Brest/SceneServer/layers/0";

        // URL for an image service to use as an elevation source
        private string _elevationSourceUrl = @"https://scene.arcgis.com/arcgis/rest/services/BREST_DTM_1M/ImageServer";

        // Location viewshed analysis to show visible and obstructed areas from the camera
        private LocationViewshed _viewshedForCamera;

        public ViewshedCamera()
        {
            InitializeComponent ();

            // Create the Scene, basemap, camera, and location viewshed analysis
            Initialize();
        }

        private void Initialize()
        {
            // Create a new Scene with an imagery basemap
            Scene myScene = new Scene(Basemap.CreateImagery());

            // Create a scene layer to show buildings in the Scene
            ArcGISSceneLayer buildingsLayer = new ArcGISSceneLayer(new Uri(_buildingsServiceUrl));
            myScene.OperationalLayers.Add(buildingsLayer);

            // Create an elevation source for the Scene
            ArcGISTiledElevationSource elevationSrc = new ArcGISTiledElevationSource(new Uri(_elevationSourceUrl));
            myScene.BaseSurface.ElevationSources.Add(elevationSrc);

            // Add the Scene to the SceneView
            MySceneView.Scene = myScene;

            // Set the viewpoint with a new camera focused on the castle in Brest
            Camera observerCamera = new Camera(new MapPoint(-4.49492, 48.3808, 48.2511, SpatialReferences.Wgs84), 344.488, 74.1212, 0.0);
            MySceneView.SetViewpointCameraAsync(observerCamera);

            // Create a LocationViewshed analysis using the camera as the observer
            _viewshedForCamera = new LocationViewshed(observerCamera, 1, 1000);

            // Create an analysis overlay to contain the viewshed analysis results
            AnalysisOverlay viewshedOverlay = new AnalysisOverlay();

            // Add the location viewshed analysis to the analysis overlay, then add the overlay to the scene view
            viewshedOverlay.Analyses.Add(_viewshedForCamera);
            MySceneView.AnalysisOverlays.Add(viewshedOverlay);
        }

        private void UpdateObserverWithCamera(object sender, EventArgs e)
        {
            // Use the current camera to update the observer for the location viewshed analysis
            _viewshedForCamera.UpdateFromCamera(MySceneView.Camera);
        }
    }
}
XAML
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:esriUI="clr-namespace:Esri.ArcGISRuntime.Xamarin.Forms;assembly=Esri.ArcGISRuntime.Xamarin.Forms"
             x:Class="ArcGISRuntime.Samples.ViewshedCamera.ViewshedCamera">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="*" />
            <RowDefinition Height="Auto" />
        </Grid.RowDefinitions>
        <esriUI:SceneView x:Name="MySceneView" Grid.Row="0" />
        <Button x:Name="UpdateObserverButton"
                Text="Viewshed from Here"
                Clicked="UpdateObserverWithCamera"
                Grid.Row="1" />
    </Grid>
</ContentPage>
See Also
Additional Examples
Hyperlink to ExampleDescription
ViewshedCameraAnalyze the viewshed for a camera. A viewshed shows the visible and obstructed areas from an observer's vantage point.
ViewshedLocationPerform a viewshed analysis from a defined vantage point. Viewshed analyses have several configuration options that are demonstrated in this sample.