Get elevation at point

View on GitHub
Sample viewer app

Get the elevation for a given point on a surface in a scene.

Image of get elevation at point

Use case

Knowing the elevation at a given point in a landscape can aid in navigation, planning and survey in the field.

How to use the sample

Tap anywhere on the surface to get the elevation at that point. Elevation is reported in meters since the scene view is in WGS84.

How it works

  1. Create a SceneView and Scene with an imagery base map.
  2. Set an ArcGISTiledElevationSource as the elevation source of the scene's base surface.
  3. Use the screenToBaseSurface(screenPoint) method on the scene view to convert the tapped screen point into a point on surface.
  4. Use the getElevationAsync(surfacePoint) method on the base surface to asynchronously get the elevation.

Relevant API

  • ArcGISTiledElevationSource
  • BaseSurface
  • ElevationSourcesList
  • SceneView

Additional information

getElevationAsync(surfacePoint) retrieves the most accurate available elevation value at a given point. To do this, the method must go to the server or local raster file and load the highest level of detail of data for the target location and return the elevation value.

If multiple elevation sources are present in the surface, the top most visible elevation source with a valid elevation in the given location is used to determine the result.

Tags

elevation, MapViews SceneViews and UI, surface

Sample Code

MainActivity.java
                                                                                                                                  
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
/* Copyright 2019 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.getelevationatpoint;

import java.util.concurrent.ExecutionException;

import android.graphics.Color;
import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import android.util.Log;
import android.view.MotionEvent;
import android.widget.Toast;

import com.esri.arcgisruntime.concurrent.ListenableFuture;
import com.esri.arcgisruntime.geometry.Point;
import com.esri.arcgisruntime.mapping.ArcGISScene;
import com.esri.arcgisruntime.mapping.ArcGISTiledElevationSource;
import com.esri.arcgisruntime.mapping.Basemap;
import com.esri.arcgisruntime.mapping.view.Camera;
import com.esri.arcgisruntime.mapping.view.DefaultSceneViewOnTouchListener;
import com.esri.arcgisruntime.mapping.view.Graphic;
import com.esri.arcgisruntime.mapping.view.GraphicsOverlay;
import com.esri.arcgisruntime.mapping.view.SceneView;
import com.esri.arcgisruntime.symbology.SimpleMarkerSymbol;

public class MainActivity extends AppCompatActivity {

  private static final String TAG = MainActivity.class.getSimpleName();

  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());

    // get a reference to the scene view and set the scene to it
    mSceneView = findViewById(R.id.sceneView);
    mSceneView.setScene(scene);

    // create an elevation source, and add this to the base surface of the scene
    ArcGISTiledElevationSource elevationSource = new ArcGISTiledElevationSource(
        getString(R.string.elevation_image_service));
    scene.getBaseSurface().getElevationSources().add(elevationSource);

    // create a point symbol to mark where elevation is being measured
    SimpleMarkerSymbol circleSymbol = new SimpleMarkerSymbol(SimpleMarkerSymbol.Style.CIRCLE, Color.RED, 10);

    // create a graphics overlay
    GraphicsOverlay graphicsOverlay = new GraphicsOverlay(GraphicsOverlay.RenderingMode.DYNAMIC);
    mSceneView.getGraphicsOverlays().add(graphicsOverlay);

    // add a camera and initial camera position
    Camera camera = new Camera(28.42, 83.9, 10000.0, 10.0, 80.0, 0.0);
    mSceneView.setViewpointCamera(camera);

    // create a touch listener to handle taps
    mSceneView.setOnTouchListener(new DefaultSceneViewOnTouchListener(mSceneView) {
      @Override public boolean onSingleTapConfirmed(MotionEvent motionEvent) {
        // clear any existing graphics from the graphics overlay
        graphicsOverlay.getGraphics().clear();
        // get the tapped screen point
        android.graphics.Point screenPoint = new android.graphics.Point(Math.round(motionEvent.getX()),
            Math.round(motionEvent.getY()));
        // convert the screen point to a point on the surface
        Point surfacePoint = mSceneView.screenToBaseSurface(screenPoint);
        if (surfacePoint == null) {
          Toast.makeText(MainActivity.this, "Cannot get an elevation for a point which is not on the surface.",
              Toast.LENGTH_SHORT).show();
          return super.onSingleTapConfirmed(motionEvent);
        }
        // create a new graphic at the surface point and add it to the graphics overlay
        Graphic surfacePointGraphic = new Graphic(surfacePoint, circleSymbol);
        graphicsOverlay.getGraphics().add(surfacePointGraphic);

        // get the surface elevation at the surface point
        ListenableFuture<Double> elevationFuture = scene.getBaseSurface().getElevationAsync(surfacePoint);
        elevationFuture.addDoneListener(() -> {
          try {
            Double elevation = elevationFuture.get();
            String elevationMessage = "Elevation at tapped point: " + Math.round(elevation) + 'm';
            Toast.makeText(MainActivity.this, elevationMessage, Toast.LENGTH_LONG).show();
            Log.i(TAG, elevationMessage);
          } catch (ExecutionException | InterruptedException e) {
            String error = "Error getting elevation: " + e.getMessage();
            Toast.makeText(MainActivity.this, error, Toast.LENGTH_LONG).show();
            Log.e(TAG, error);
          }
        });

        return super.onSingleTapConfirmed(motionEvent);
      }
    });
  }

  @Override
  protected void onPause() {
    mSceneView.pause();
    super.onPause();
  }

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

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

Your browser is no longer supported. Please upgrade your browser for the best experience. See our browser deprecation post for more details.