Extrude features based on their attributes.
Use case
Extrusion is the process of stretching a flat, 2D shape vertically to create a 3D object in a scene. For example, you can extrude building polygons by a height value to create three-dimensional building shapes.
How to use the sample
Press the button to switch between using population density and total population for extrusion. Higher extrusion directly corresponds to higher attribute values.
How it works
- Create a
ServiceFeatureTable
from a URL. - Create a feature layer from the service feature table.
- Make sure to set the rendering mode to dynamic.
- Apply a
SimpleRenderer
to the feature layer. - Set
ExtrusionMode
of render,renderer.SceneProperties.ExtrusionMode = SceneProperties.ExtrusionMode.BaseHeight
. - Set extrusion expression of renderer,
renderer.SceneProperties.ExtrusionExpression = "[POP2007]/ 10"
.
Relevant API
- ExtrusionExpression
- ExtrusionMode
- FeatureLayer
- FeatureLayer
- SceneProperties
- ServiceFeatureTable
- SimpleRenderer
Tags
3D, extrude, extrusion, extrusion expression, height, renderer, scene
Sample Code
FeatureLayerExtrusion.cs
// 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: 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.
using Android.App;
using Android.OS;
using Android.Views;
using Android.Widget;
using Esri.ArcGISRuntime.Data;
using Esri.ArcGISRuntime.Geometry;
using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.Symbology;
using Esri.ArcGISRuntime.UI;
using Esri.ArcGISRuntime.UI.Controls;
using System;
using System.Drawing;
namespace ArcGISRuntime.Samples.FeatureLayerExtrusion
{
[Activity (ConfigurationChanges=Android.Content.PM.ConfigChanges.Orientation | Android.Content.PM.ConfigChanges.ScreenSize)]
[ArcGISRuntime.Samples.Shared.Attributes.Sample(
name: "Feature layer extrusion",
category: "Symbology",
description: "Extrude features based on their attributes.",
instructions: "Press the button to switch between using population density and total population for extrusion. Higher extrusion directly corresponds to higher attribute values.",
tags: new[] { "3D", "extrude", "extrusion", "extrusion expression", "height", "renderer", "scene" })]
public class FeatureLayerExtrusion : Activity
{
// Hold a reference to the scene view
private SceneView _mySceneView;
private Button _button_ToggleExtrusionData;
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
Title = "Feature layer extrusion";
// Create the UI, setup the control references
CreateLayout();
Initialize();
}
private void Initialize()
{
try
{
// Define the Uri for the service feature table (US state polygons)
Uri myServiceFeatureTable_Uri = new Uri("https://sampleserver6.arcgisonline.com/arcgis/rest/services/Census/MapServer/3");
// Create a new service feature table from the Uri
ServiceFeatureTable myServiceFeatureTable = new ServiceFeatureTable(myServiceFeatureTable_Uri);
// Create a new feature layer from the service feature table
FeatureLayer myFeatureLayer = new FeatureLayer(myServiceFeatureTable)
{
// Set the rendering mode of the feature layer to be dynamic (needed for extrusion to work)
RenderingMode = FeatureRenderingMode.Dynamic
};
// Create a new simple line symbol for the feature layer
SimpleLineSymbol mySimpleLineSymbol = new SimpleLineSymbol(SimpleLineSymbolStyle.Solid, Color.Black, 1);
// Create a new simple fill symbol for the feature layer
SimpleFillSymbol mysimpleFillSymbol = new SimpleFillSymbol(SimpleFillSymbolStyle.Solid, Color.Blue, mySimpleLineSymbol);
// Create a new simple renderer for the feature layer
SimpleRenderer mySimpleRenderer = new SimpleRenderer(mysimpleFillSymbol);
// Get the scene properties from the simple renderer
RendererSceneProperties myRendererSceneProperties = mySimpleRenderer.SceneProperties;
// Set the extrusion mode for the scene properties
myRendererSceneProperties.ExtrusionMode = ExtrusionMode.AbsoluteHeight;
// Set the initial extrusion expression
myRendererSceneProperties.ExtrusionExpression = "[POP2007] / 10";
// Set the feature layer's renderer to the define simple renderer
myFeatureLayer.Renderer = mySimpleRenderer;
// Create a new scene with the topographic backdrop
Scene myScene = new Scene(BasemapStyle.ArcGISTopographic);
// Set the scene view's scene to the newly create one
_mySceneView.Scene = myScene;
// Add the feature layer to the scene's operational layer collection
myScene.OperationalLayers.Add(myFeatureLayer);
// Create a new map point to define where to look on the scene view
MapPoint myMapPoint = new MapPoint(-10974490, 4814376, 0, SpatialReferences.WebMercator);
// Create a new orbit location camera controller using the map point and defined distance
OrbitLocationCameraController myOrbitLocationCameraController = new OrbitLocationCameraController(myMapPoint, 20000000);
// Set the scene view's camera controller to the orbit location camera controller
_mySceneView.CameraController = myOrbitLocationCameraController;
}
catch (Exception ex)
{
// Something went wrong, display the error
AlertDialog.Builder alert = new AlertDialog.Builder(this);
alert.SetTitle("Error");
alert.SetMessage(ex.Message);
alert.Show();
}
}
private void ChangeExtrusionExpression()
{
// Get the first layer from the scene view's operation layers, it should be a feature layer
FeatureLayer myFeatureLayer = (FeatureLayer)_mySceneView.Scene.OperationalLayers[0];
// Get the renderer from the feature layer
Renderer myRenderer = myFeatureLayer.Renderer;
// Get the scene properties from the feature layer's renderer
RendererSceneProperties myRendererSceneProperties = myRenderer.SceneProperties;
// Toggle the feature layer's scene properties renderer extrusion expression and change the button text
if (_button_ToggleExtrusionData.Text == "Show population density")
{
// An offset of 100000 is added to ensure that polygons for large areas (like Alaska)
// with low populations will be extruded above the curvature of the Earth.
myRendererSceneProperties.ExtrusionExpression = "[POP07_SQMI] * 5000 + 100000";
_button_ToggleExtrusionData.Text = "Show total population";
}
else if (_button_ToggleExtrusionData.Text == "Show total population")
{
myRendererSceneProperties.ExtrusionExpression = "[POP2007] / 10";
_button_ToggleExtrusionData.Text = "Show population density";
}
}
private void Button_ToggleExtrusionData_Clicked(object sender, EventArgs e)
{
// Call the function to change the feature layer's renderer scene properties extrusion expression
ChangeExtrusionExpression();
}
private void CreateLayout()
{
// Create a new vertical layout for the app
LinearLayout layout = new LinearLayout(this) { Orientation = Orientation.Vertical };
// Create Button
_button_ToggleExtrusionData = new Button(this)
{
Text = "Show population density"
};
_button_ToggleExtrusionData.Click += Button_ToggleExtrusionData_Clicked;
// Add Button to the layout
layout.AddView(_button_ToggleExtrusionData);
// Add the scene view to the layout
_mySceneView = new SceneView(this);
layout.AddView(_mySceneView);
// Show the layout in the app
SetContentView(layout);
}
protected override void OnDestroy()
{
base.OnDestroy();
// Remove the sceneview
(_mySceneView.Parent as ViewGroup).RemoveView(_mySceneView);
_mySceneView.Dispose();
_mySceneView = null;
}
}
}