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 anAGSSceneView
object. - Create an
AGSDistanceCompositeSceneSymbol
object. - Create
AGSDistanceSymbolRange
objects specifying anAGSSymbol
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
//
// 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
class DistanceCompositeSymbolViewController: UIViewController {
@IBOutlet var sceneView: AGSSceneView!
override func viewDidLoad() {
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 view
self.sceneView.scene = scene
// add base surface for elevation data
let 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 symbols
let circleSymbol = AGSSimpleMarkerSymbol(style: .circle, color: .red, size: 10.0)
let coneSymbol = AGSSimpleMarkerSceneSymbol.cone(with: .red, diameter: 200, height: 600)
coneSymbol.pitch = -90.0
let modelSymbol = AGSModelSceneSymbol(name: "Bristol", extension: "dae", scale: 100.0)
modelSymbol.load { [weak self] (error) in
if let error = error {
self?.presentAlert(error: error)
return
}
// set up the distance composite symbol
let 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 graphic
let 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 graphic
let cameraController = AGSOrbitGeoElementCameraController(targetGeoElement: aircraftGraphic, distance: 4000)
cameraController.cameraPitchOffset = 80
cameraController.cameraHeadingOffset = -30
self?.sceneView.cameraController = cameraController
}
}
}