This sample demonstrates how to display custom labels in a 3D scene.
      
  
    
Use case
Labeling features is useful to visually display information or attributes on a scene. For example, city officials or maintenance crews may want to show installation dates of features of a gas network.
How to use the sample
Pan and zoom to explore the scene. Notice the labels showing installation dates of features in the 3D gas network.
How it works
- Create an 
Scenefrom aPortalItem. - Add the scene to an 
SceneViewand load it. - After loading is complete, obtain the 
FeatureLayerfrom one of theGroupLayers in the scene'soperationalLayers. - Create a 
TextSymbolto define how labels are stylized. - After the 
Scenehas loaded, obtain theFeatureLayerfrom the scene'soperationalLayers. - Create an 
LabelDefinitionusing anArcadeLabelExpression. 
- Set the "labelExpressionInfo.expression" key to define what text the label should display. You can use fields of the feature by using 
$feature.NAMEin the expression. 
- Add the definition to the feature layer's 
labelDefinitionsarray. 
Relevant API
- ArcadeLabelExpression
 - FeatureLayer
 - LabelDefinition
 - Scene
 - SceneView
 - TextSymbol
 
About the data
This sample shows a New York City infrastructure scene hosted on ArcGIS Online.
Tags
3D, arcade, attribute, buildings, label, model, scene, symbol, text, URL, visualization
Sample Code
Display3DLabelsInScene.qml
// [WriteFile Name=Display3DLabelsInScene, Category=Scenes]
// [Legal]
// Copyright 2021 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.
// [Legal]
import QtQuick 2.6
import Esri.ArcGISRuntime 100.15
Rectangle {
    id: rootRectangle
    clip: true
    width: 800
    height: 600
    SceneView {
        id: sceneView
        anchors.fill: parent
        Component.onCompleted: {
            // Set the focus on SceneView to initially enable keyboard navigation
            forceActiveFocus();
        }
        // add a Scene to the SceneView
        Scene {
            id: nycScene
            initUrl: "https://www.arcgis.com/home/item.html?id=850dfee7d30f4d9da0ebca34a533c169"
            LabelDefinition {
                id: gasLineLabelDefinition
                expression: ArcadeLabelExpression {
                    expression: "Text($feature.INSTALLATIONDATE, 'D MMM Y')"
                }
                textSymbol: TextSymbol {
                    color: "#ffa500"
                    haloColor: "white"
                    haloWidth: 2.0
                    size: 16.0
                }
                placement: Enums.LabelingPlacementLineAboveAlong
                useCodedValues: true
            }
            onLoadStatusChanged: {
                if (loadStatus !== Enums.LoadStatusLoaded)
                    return;
                // Search for a specific layer from the web scene's operational layers to apply labels to
                nycScene.operationalLayers.forEach(layer => {
                                                       if (layer.name === "Gas") {
                                                           // The Gas layer is a GroupLayer type and we must extract our target FeatureLayer from it
                                                           const gasLayer = layer.layers.get(0);
                                                           // This layer has a preexisting label definition from the web that we don't want to display
                                                           gasLayer.labelDefinitions.clear();
                                                           gasLayer.labelDefinitions.append(gasLineLabelDefinition);
                                                           gasLayer.labelsEnabled = true;
                                                       }
                                                   });
            }
        }
    }
}