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// Copyright 2018 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: https://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.Symbology;
using Esri.ArcGISRuntime.UI;
using Esri.ArcGISRuntime.UI.Controls;
using Esri.ArcGISRuntime.UI.GeoAnalysis;
using System;
using System.Drawing;
using System.Windows;
using System.Windows.Input;
using Point = System.Windows.Point;
namespace ArcGIS.WPF.Samples.ViewshedLocation
{
[ArcGIS.Samples.Shared.Attributes.Sample(
name: "Viewshed (location)",
category: "Analysis",
description: "Perform a viewshed analysis from a defined vantage point.",
instructions: "Use the sliders to change the properties (heading, pitch, etc.), of the viewshed and see them updated in real time.",
tags: new[] { "3D", "frustum", "scene", "viewshed", "visibility analysis" })]
public partial class ViewshedLocation
{
// Hold the URL to the elevation source.
private readonly Uri _localElevationImageService = new Uri("https://elevation3d.arcgis.com/arcgis/rest/services/WorldElevation3D/Terrain3D/ImageServer");
// Hold the URL to the buildings scene layer.
private readonly Uri _buildingsUrl = new Uri("https://tiles.arcgis.com/tiles/P3ePLMYs2RVChkJx/arcgis/rest/services/Buildings_Brest/SceneServer/layers/0");
// Hold a reference to the viewshed analysis.
private LocationViewshed _viewshed;
// Hold a reference to the analysis overlay that will hold the viewshed analysis.
private AnalysisOverlay _analysisOverlay;
// Graphics overlay for viewpoint symbol.
private GraphicsOverlay _viewpointOverlay;
// Symbol for viewpoint.
private SimpleMarkerSceneSymbol _viewpointSymbol;
// Flag indicating if the viewshed will move with the mouse.
private bool _subscribedToMouseMoves;
// Height of the viewpoint above the ground.
private double _viewHeight;
public ViewshedLocation()
{
InitializeComponent();
// Initialize the sample.
Initialize();
}
private void Initialize()
{
_viewHeight = HeightSlider.Value;
// Create the scene with the imagery basemap.
Scene myScene = new Scene(BasemapStyle.ArcGISImageryStandard);
MySceneView.Scene = myScene;
// Add the surface elevation.
Surface mySurface = new Surface();
mySurface.ElevationSources.Add(new ArcGISTiledElevationSource(_localElevationImageService));
myScene.BaseSurface = mySurface;
// Add the scene layer.
ArcGISSceneLayer sceneLayer = new ArcGISSceneLayer(_buildingsUrl);
myScene.OperationalLayers.Add(sceneLayer);
// Create the MapPoint representing the initial location.
MapPoint initialLocation = new MapPoint(-4.5, 48.4, 46 + _viewHeight);
// Create the location viewshed analysis.
_viewshed = new LocationViewshed(
initialLocation,
HeadingSlider.Value,
PitchSlider.Value,
HorizontalAngleSlider.Value,
VerticalAngleSlider.Value,
MinimumDistanceSlider.Value,
MaximumDistanceSlider.Value);
// Create a camera based on the initial location.
Camera camera = new Camera(initialLocation, 200.0, 20.0, 70.0, 0.0);
// Create a symbol for the viewpoint.
_viewpointSymbol = SimpleMarkerSceneSymbol.CreateSphere(Color.Blue, 10, SceneSymbolAnchorPosition.Center);
// Add the symbol to the viewpoint overlay.
_viewpointOverlay = new GraphicsOverlay
{
SceneProperties = new LayerSceneProperties(SurfacePlacement.Absolute)
};
_viewpointOverlay.Graphics.Add(new Graphic(initialLocation, _viewpointSymbol));
// Apply the camera to the scene view.
MySceneView.SetViewpointCamera(camera);
// Create an analysis overlay for showing the viewshed analysis.
_analysisOverlay = new AnalysisOverlay();
// Add the viewshed analysis to the overlay.
_analysisOverlay.Analyses.Add(_viewshed);
// Add the analysis overlay to the SceneView.
MySceneView.AnalysisOverlays.Add(_analysisOverlay);
// Add the graphics overlay
MySceneView.GraphicsOverlays.Add(_viewpointOverlay);
// Update the frustum outline Color.
// The frustum outline shows the volume in which the viewshed analysis is performed.
Viewshed.FrustumOutlineColor = Color.Blue;
// Subscribe to tap events. This enables the 'pick up' and 'drop' workflow for moving the viewpoint.
MySceneView.GeoViewTapped += MySceneViewOnGeoViewTapped;
}
private void MySceneViewOnGeoViewTapped(object sender, GeoViewInputEventArgs geoViewInputEventArgs)
{
// The viewshed observer is picked up and moving. Drop it.
if (_subscribedToMouseMoves)
{
MySceneView.MouseMove -= MySceneViewOnMouseMove;
}
// The viewshed observer is currently pinned. Pick it up.
else
{
MySceneView.MouseMove += MySceneViewOnMouseMove;
}
// Toggle the viewshed movement flag.
_subscribedToMouseMoves = !_subscribedToMouseMoves;
}
private void MySceneViewOnMouseMove(object sender, MouseEventArgs mouseEventArgs)
{
// Get the mouse position.
Point cursorSceenPoint = mouseEventArgs.GetPosition(MySceneView);
// Get the corresponding MapPoint.
MapPoint onMapLocation = MySceneView.ScreenToBaseSurface(cursorSceenPoint);
// Return if the MapPoint is null. This might happen if mouse leaves SceneView area.
if (onMapLocation == null)
{
return;
}
// Adjust the Z value of the MapPoint to reflect the selected height.
onMapLocation = new MapPoint(onMapLocation.X, onMapLocation.Y, onMapLocation.Z + _viewHeight);
// Update the viewshed.
_viewshed.Location = onMapLocation;
// Update the viewpoint symbol.
_viewpointOverlay.Graphics.Clear();
_viewpointOverlay.Graphics.Add(new Graphic(onMapLocation, _viewpointSymbol));
}
private void HandleSettingsChange(object sender, RoutedEventArgs e)
{
// Return if viewshed hasn't been created yet. This happens when the sample is starting.
if (_viewshed == null)
{
return;
}
// Calculate the difference between the old and new height.
double difference = HeightSlider.Value - _viewHeight;
// Update the view height value to the new value.
_viewHeight = HeightSlider.Value;
// Move the viewshed to the new height.
_viewshed.Location = new MapPoint(_viewshed.Location.X, _viewshed.Location.Y, _viewshed.Location.Z + difference);
// Update the viewshed settings.
_viewshed.Heading = HeadingSlider.Value;
_viewshed.Pitch = PitchSlider.Value;
_viewshed.HorizontalAngle = HorizontalAngleSlider.Value;
_viewshed.VerticalAngle = VerticalAngleSlider.Value;
_viewshed.MinDistance = MinimumDistanceSlider.Value;
_viewshed.MaxDistance = MaximumDistanceSlider.Value;
// Update visibility of the viewshed analysis.
_viewshed.IsVisible = (bool)AnalysisVisibilityCheck.IsChecked;
// Update visibility of the frustum. Note that the frustum will be invisible
// regardless of this setting if the viewshed analysis is not visible.
_viewshed.IsFrustumOutlineVisible = (bool)FrustumVisibilityCheck.IsChecked;
// Update the viewpoint graphic.
_viewpointOverlay.Graphics.Clear();
_viewpointOverlay.Graphics.Add(new Graphic(_viewshed.Location, _viewpointSymbol));
}
}
}
