Scene property expressions

View on GitHub
Sample viewer app

Update the orientation of a graphic using expressions based on its attributes.

Image of scene property expressions

Use case

Instead of reading the attribute and changing the rotation on the symbol for a single graphic (a manual CPU operation), you can bind the rotation to an expression that applies to the whole overlay (an automatic GPU operation). This usually results in a noticeable performance boost (smooth rotations).

How to use the sample

Adjust the heading and pitch sliders to rotate the cone.

How it works

  1. Create a new GraphicsOverlay.
  2. Create a new SimpleRenderer.
  3. Set the heading expression to [HEADING] and the pitch expression to [PITCH] with simpleRenderer.getSceneProperties().setHeadingExpression(...).
  4. Apply the renderer to the graphics overlay with graphicsOverlay.setRenderer(simpleRenderer).
  5. Create a new Point and a new Graphic and add it to the overlay with e.g. graphicsOverlay.getGraphics().add(graphic).
  6. To update the graphic's rotation, update the HEADING or PITCH property in the graphic's attributes with graphic.getAttributes().put(key, value).

Relevant API

  • Graphic
  • GraphicsOverlay
  • SceneProperties
  • SceneProperties.setHeadingExpression
  • SceneProperties.setPitchExpression
  • SimpleRenderer

Tags

3D, expression, graphics, heading, pitch, rotation, scene, symbology

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
131
132
/*
 *  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.scenepropertyexpressions;

import android.graphics.Color;
import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import android.widget.SeekBar;

import com.esri.arcgisruntime.geometry.Point;
import com.esri.arcgisruntime.geometry.SpatialReferences;
import com.esri.arcgisruntime.mapping.ArcGISScene;
import com.esri.arcgisruntime.mapping.Basemap;
import com.esri.arcgisruntime.mapping.view.Camera;
import com.esri.arcgisruntime.mapping.view.Graphic;
import com.esri.arcgisruntime.mapping.view.GraphicsOverlay;
import com.esri.arcgisruntime.mapping.view.LayerSceneProperties;
import com.esri.arcgisruntime.mapping.view.SceneView;
import com.esri.arcgisruntime.symbology.SceneSymbol;
import com.esri.arcgisruntime.symbology.SimpleMarkerSceneSymbol;
import com.esri.arcgisruntime.symbology.SimpleRenderer;

public class MainActivity extends AppCompatActivity {

  private SceneView mSceneView;

  private static final int PITCH_OFFSET = 90;
  private static final String HEADING_EXPRESSION = "HEADING";
  private static final String PITCH_EXPRESSION = "PITCH";

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

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

    // create a scene with an imagery basemap
    ArcGISScene scene = new ArcGISScene(Basemap.Type.IMAGERY);

    // add the SceneView to the stack pane
    mSceneView.setScene(scene);

    // add a camera and initial camera position
    Point point = new Point(83.9, 28.4, 1000, SpatialReferences.getWgs84());
    Camera camera = new Camera(point, 1000, 0, 50, 0);
    mSceneView.setViewpointCamera(camera);

    // create a graphics overlay
    GraphicsOverlay graphicsOverlay = new GraphicsOverlay();
    graphicsOverlay.getSceneProperties().setSurfacePlacement(LayerSceneProperties.SurfacePlacement.RELATIVE);
    mSceneView.getGraphicsOverlays().add(graphicsOverlay);

    // add renderer using rotation expressions
    SimpleRenderer renderer = new SimpleRenderer();
    renderer.getSceneProperties().setHeadingExpression('[' + HEADING_EXPRESSION + ']');
    renderer.getSceneProperties().setPitchExpression('[' + PITCH_EXPRESSION + ']');
    graphicsOverlay.setRenderer(renderer);

    // create a red cone graphic
    // in this sample we've set the anchor position to center. By default, the anchor position is BOTTOM
    SimpleMarkerSceneSymbol coneSymbol = SimpleMarkerSceneSymbol.createCone(Color.RED, 100, 100, SceneSymbol.AnchorPosition.CENTER);
    coneSymbol.setPitch(-PITCH_OFFSET);  // correct symbol's default pitch
    Graphic cone = new Graphic(new Point(83.9, 28.41, 200, SpatialReferences.getWgs84()), coneSymbol);
    graphicsOverlay.getGraphics().add(cone);

    // bind attribute based on values in seek bars
    SeekBar headingSeekBar = findViewById(R.id.headingSeekBar);
    cone.getAttributes().put(HEADING_EXPRESSION, headingSeekBar.getProgress());
    headingSeekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
      @Override public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
        cone.getAttributes().put(HEADING_EXPRESSION, progress);
      }

      @Override public void onStartTrackingTouch(SeekBar seekBar) {

      }

      @Override public void onStopTrackingTouch(SeekBar seekBar) {

      }
    });
    SeekBar pitchSeekBar = findViewById(R.id.pitchSeekBar);
    cone.getAttributes().put(PITCH_EXPRESSION, pitchSeekBar.getProgress() - PITCH_OFFSET);
    pitchSeekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
      @Override public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
        cone.getAttributes().put(PITCH_EXPRESSION, progress - PITCH_OFFSET);
      }

      @Override public void onStartTrackingTouch(SeekBar seekBar) {

      }

      @Override public void onStopTrackingTouch(SeekBar seekBar) {

      }
    });
  }

  @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.