Viewshed camera

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Sample viewer app

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

Image of viewshed camera

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

  1. Get the current camera from the scene with SceneView.getCurrentViewpointCamera().
  2. Create a LocationViewshed, passing in the Camera and a min/max distance.
  3. Update the viewshed from a camera with viewshed.updateFromCamera(camera).

Relevant API

  • AnalysisOverlay
  • ArcGISSceneLayer
  • ArcGISTiledElevationSource
  • Camera
  • LocationViewshed

About the data

The scene shows a buildings layer in Brest, France with a local elevation source image service both hosted on ArcGIS Online.

Tags

3D, scene, viewshed, visibility analysis

Sample Code

MainActivity.java
                                                                                                 
/* 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 androidx.appcompat.app.AppCompatActivity;
import android.widget.Button;

import com.esri.arcgisruntime.geoanalysis.LocationViewshed;
import com.esri.arcgisruntime.layers.ArcGISSceneLayer;
import com.esri.arcgisruntime.mapping.ArcGISScene;
import com.esri.arcgisruntime.mapping.ArcGISTiledElevationSource;
import com.esri.arcgisruntime.mapping.Basemap;
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);

    // create a scene and add a basemap to it
    ArcGISScene scene = new ArcGISScene();
    scene.setBasemap(Basemap.createImagery());

    // 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(48.3808, -4.49492, 48.2511, 344.488, 74.1212, 0.0);
    mSceneView.setViewpointCamera(camera);

    // add base surface for elevation data to the scene view
    Surface surface = new Surface();
    ArcGISTiledElevationSource brestElevationSource = new ArcGISTiledElevationSource(getString(R.string.brest_dtm));
    surface.getElevationSources().add(brestElevationSource);
    scene.setBaseSurface(surface);

    // add a scene layer to the scene
    ArcGISSceneLayer brestBuildingLayer = new ArcGISSceneLayer(getString(R.string.brest_building_layer));
    scene.getOperationalLayers().add(brestBuildingLayer);

    // 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() {
    super.onPause();
    // pause SceneView
    mSceneView.pause();
  }

  @Override
  protected void onResume() {
    super.onResume();
    // resume SceneView
    mSceneView.resume();
  }

  @Override
  protected void onDestroy() {
    super.onDestroy();
    // dispose SceneView
    mSceneView.dispose();
  }
}