Analyze the viewshed for a camera. A viewshed shows the visible and obstructed areas from an observer's vantage point.
Use case
A viewshed analysis is a type of visual analysis you can perform on a scene. The viewshed aims to answer the question 'What can I see from a given location?'. The output is an overlay with two different colors - one representing the visible areas (green) and the other representing the obstructed areas (red).
How to use the sample
The sample will start with a viewshed created from the initial camera location, so only the visible (green) portion of the viewshed will be visible. Move around the scene to see the obstructed (red) portions. Use the 'Update from Camera' button to update the viewshed to the current camera position.
How it works
- Get the current camera from the scene with
SceneView.getCurrentViewpointCamera()
. - Create a
LocationViewshed
, passing in theCamera
and a min/max distance. - Update the viewshed from a camera with
viewshed.updateFromCamera(camera)
.
Relevant API
- AnalysisOverlay
- IntegratedMeshLayer
- ArcGISTiledElevationSource
- Camera
- LocationViewshed
About the data
The scene shows an integrated mesh layer of Girona, Spain with the World Elevation source image service both hosted on ArcGIS Online.
Tags
3D, integrated mesh, scene, viewshed, visibility analysis
Sample Code
/* 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.
*
*/
package com.esri.arcgisruntime.sample.viewshedcamera;
import android.os.Bundle;
import android.widget.Button;
import androidx.appcompat.app.AppCompatActivity;
import com.esri.arcgisruntime.ArcGISRuntimeEnvironment;
import com.esri.arcgisruntime.geoanalysis.LocationViewshed;
import com.esri.arcgisruntime.layers.IntegratedMeshLayer;
import com.esri.arcgisruntime.mapping.ArcGISScene;
import com.esri.arcgisruntime.mapping.ArcGISTiledElevationSource;
import com.esri.arcgisruntime.mapping.Basemap;
import com.esri.arcgisruntime.mapping.BasemapStyle;
import com.esri.arcgisruntime.mapping.Surface;
import com.esri.arcgisruntime.mapping.view.AnalysisOverlay;
import com.esri.arcgisruntime.mapping.view.Camera;
import com.esri.arcgisruntime.mapping.view.SceneView;
public class MainActivity extends AppCompatActivity {
private SceneView mSceneView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// authentication with an API key or named user is required to access basemaps and other
// location services
ArcGISRuntimeEnvironment.setApiKey(BuildConfig.API_KEY);
// create a scene and add a basemap to it
ArcGISScene scene = new ArcGISScene(BasemapStyle.ARCGIS_IMAGERY);
// add the scene to a scene view
mSceneView = findViewById(R.id.sceneView);
mSceneView.setScene(scene);
// set the camera to the scene view
Camera camera = new Camera(41.985, 2.82691, 124.987, 332.131, 82.4732, 0.0);
mSceneView.setViewpointCamera(camera);
// add base surface for elevation data to the scene view
Surface surface = new Surface();
ArcGISTiledElevationSource elevationSource = new ArcGISTiledElevationSource(
"https://elevation3d.arcgis.com/arcgis/rest/services/WorldElevation3D/Terrain3D/ImageServer");
surface.getElevationSources().add(elevationSource);
scene.setBaseSurface(surface);
// add an integrated mesh layer to the scene
IntegratedMeshLayer gironaMeshLayer = new IntegratedMeshLayer(
"https://tiles.arcgis.com/tiles/z2tnIkrLQ2BRzr6P/arcgis/rest/services/Girona_Spain/SceneServer");
scene.getOperationalLayers().add(gironaMeshLayer);
// create a viewshed from the camera
LocationViewshed viewshed = new LocationViewshed(camera, 1.0, 500.0);
// create an analysis overlay to add the viewshed to the scene view
AnalysisOverlay analysisOverlay = new AnalysisOverlay();
analysisOverlay.getAnalyses().add(viewshed);
mSceneView.getAnalysisOverlays().add(analysisOverlay);
// create a button to update the viewshed with the current camera
Button cameraButton = findViewById(R.id.updateViewshedButton);
cameraButton.setOnClickListener(
view -> viewshed.updateFromCamera(mSceneView.getCurrentViewpointCamera()));
}
@Override
protected void onPause() {
mSceneView.pause();
super.onPause();
}
@Override
protected void onResume() {
super.onResume();
mSceneView.resume();
}
@Override
protected void onDestroy() {
mSceneView.dispose();
super.onDestroy();
}
}