Change a graphic's symbol based on the camera's proximity to it.
Use case
When showing dense datasets, it is beneficial to reduce the detail of individual points when zooming out to avoid visual clutter and to avoid data points overlapping and obscuring each other.
How to use the sample
The sample starts looking at a plane. Zoom out from the plane to see it turn into a cone. Keeping zooming out and it will turn into a point.
How it works
Create an AGSGraphicsOverlay object and add it to an AGSSceneView object.
Create an AGSDistanceCompositeSceneSymbol object.
Create AGSDistanceSymbolRange objects specifying an AGSSymbol and the min and max distance within which the symbol should be visible.
Add the ranges to the ranges array of the distance composite scene symbol.
Create an AGSGraphic object with the distance composite scene symbol at a location and add it to the graphics overlay.
Relevant API
AGSDistanceCompositeSceneSymbol
AGSDistanceSymbolRange
AGSOrbitGeoElementCameraController
Tags
3D, data, graphic
Sample Code
DistanceCompositeSymbolViewController.swift
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//// 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.//import UIKit
import ArcGIS
classDistanceCompositeSymbolViewController: UIViewController{
@IBOutletvar sceneView: AGSSceneView!
overridefuncviewDidLoad() {
super.viewDidLoad()
// add the source code button item to the right of navigation bar (self.navigationItem.rightBarButtonItem as!SourceCodeBarButtonItem).filenames = ["DistanceCompositeSymbolViewController"]
// Initialize scene with imagery basemap style.let scene =AGSScene(basemapStyle: .arcGISImagery)
// assign scene to the scene viewself.sceneView.scene = scene
// add base surface for elevation datalet surface =AGSSurface()
/// The url of the Terrain 3D ArcGIS REST Service.let worldElevationServiceURL =URL(string: "https://elevation3d.arcgis.com/arcgis/rest/services/WorldElevation3D/Terrain3D/ImageServer")!let elevationSource =AGSArcGISTiledElevationSource(url: worldElevationServiceURL)
surface.elevationSources.append(elevationSource)
scene.baseSurface = surface
let graphicsOverlay =AGSGraphicsOverlay()
graphicsOverlay.sceneProperties?.surfacePlacement = .relative
self.sceneView.graphicsOverlays.add(graphicsOverlay)
// set up the different symbolslet circleSymbol =AGSSimpleMarkerSymbol(style: .circle, color: .red, size: 10.0)
let coneSymbol =AGSSimpleMarkerSceneSymbol.cone(with: .red, diameter: 200, height: 600)
coneSymbol.pitch =-90.0let modelSymbol =AGSModelSceneSymbol(name: "Bristol", extension: "dae", scale: 100.0)
modelSymbol.load { [weakself] (error) iniflet error = error {
self?.presentAlert(error: error)
return }
// set up the distance composite symbollet compositeSymbol =AGSDistanceCompositeSceneSymbol()
compositeSymbol.ranges.append(AGSDistanceSymbolRange(symbol: modelSymbol, minDistance: 0, maxDistance: 10000))
compositeSymbol.ranges.append(AGSDistanceSymbolRange(symbol: coneSymbol, minDistance: 10001, maxDistance: 30000))
compositeSymbol.ranges.append(AGSDistanceSymbolRange(symbol: circleSymbol, minDistance: 30001, maxDistance: 0))
// create graphiclet aircraftPosition =AGSPoint(x: -2.708471, y: 56.096575, z: 5000, spatialReference: .wgs84())
let aircraftGraphic =AGSGraphic(geometry: aircraftPosition, symbol: compositeSymbol, attributes: nil)
// add graphic to graphics overlay graphicsOverlay.graphics.add(aircraftGraphic)
// add an orbit camera controller to lock the camera to the graphiclet cameraController =AGSOrbitGeoElementCameraController(targetGeoElement: aircraftGraphic, distance: 4000)
cameraController.cameraPitchOffset =80 cameraController.cameraHeadingOffset =-30self?.sceneView.cameraController = cameraController
}
}
}