ArcGIS Runtime SDK for .NET Samples

Viewshed for camera

Visibility analysis in a scene view
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// 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.Controls;
using Esri.ArcGISRuntime.UI.GeoAnalysis;
using Foundation;
using System;
using UIKit;

namespace ArcGISRuntime.Samples.ViewshedCamera
{
    [Register("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 class ViewshedCamera : UIViewController
    {
        // Create and hold reference to the used MapView
        private SceneView _mySceneView = new SceneView();

        // URL for a scene service of buildings in Brest, France
        private string _buildingsServiceUrl = @"http://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 = @"http://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;

        // Button for updating the analysis viewpoint
        private UIButton _updateViewshedButton;

        public ViewshedCamera()
        {
            Title = "Viewshed from camera";
        }

        public override void ViewDidLoad()
        {
            base.ViewDidLoad();

            // Create the UI, setup the control references and execute initialization 
            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);
        }

        public override void ViewDidLayoutSubviews()
        {
            // Setup the visual frame for the SceneView
            _mySceneView.Frame = new CoreGraphics.CGRect(
                0, 0, View.Bounds.Width, View.Bounds.Height);

            // Update the visual frame for the button
            _updateViewshedButton.Frame = new CoreGraphics.CGRect(0, View.Bounds.Height - 60, View.Bounds.Width, 30);

            base.ViewDidLayoutSubviews();
        }
        
        private void CreateLayout()
        {
            // Create a button to update the viewshed using the current camera
            _updateViewshedButton = new UIButton(new CoreGraphics.CGRect(0,View.Bounds.Height - 60,View.Bounds.Width,30));
            _updateViewshedButton.SetTitle("Viewshed from here", UIControlState.Normal);
            _updateViewshedButton.TouchUpInside += UpdateObserverWithCamera;

            // Add SceneView and button to the page
            View.AddSubviews(_mySceneView, _updateViewshedButton);
        }
    }
}


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