Animate 3D graphic

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Sample viewer app
An AGSOrbitGeoElementCameraController follows a graphic while the graphic's position and rotation are animated.
Animate 3D graphic sample
Use case

Visualize movement through a 3D landscape.
How to use the sample

Tap the bottom buttons to adjust settings for the animation:
Mission: change the flight path, speed, and view progress
Play/Pause: toggle the animation
Stats: view the attributes of the animation
Camera: change the camera distance, heading, pitch, and other camera properties.
How it works

Create an AGSGraphicsOverlay object and add it to the scene view.
Create an AGSModelSceneSymbol object.
Create an AGSGraphic object configured with a point and the model scene symbol.
Add heading, pitch, and roll attributes to the graphic.
Create an AGSSimpleRenderer object and set its expression properties.
Add graphic and a renderer to the graphics overlay.
Create an AGSOrbitGeoElementCameraController which is set to target the graphic.
Assign the camera controller to the AGSSceneView.
Update the graphic's location, heading, pitch, and roll.
Relevant API

AGSCamera
AGSGlobeCameraController
AGSGraphic
AGSGraphicsOverlay
AGSModelSceneSymbol
AGSOrbitGeoElementCameraController
AGSRenderer
AGSScene
AGSSceneView
AGSSurfacePlacement
Offline data

This sample uses the following data which are all included and downloaded on-demand:
Sample Code

Animate3DGraphicViewController.swift
CameraSettingsViewController.swift
MissionSettingsViewController.swift
PlaneStatsViewController.swift
Use dark colors for code blocksCopy
//
// 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 Animate3DGraphicViewController: UIViewController {
    @IBOutlet private var sceneView: AGSSceneView!
    @IBOutlet private var mapView: AGSMapView!
    @IBOutlet private var playBBI: UIBarButtonItem!

    private var missionFileNames = ["GrandCanyon.csv", "Hawaii.csv", "Pyrenees.csv", "Snowdon.csv"]
    private var selectedMissionIndex = 0
    private var sceneGraphicsOverlay = AGSGraphicsOverlay()
    private var mapGraphicsOverlay = AGSGraphicsOverlay()
    private var frames: [Frame] = []
    private var planeModelGraphic: AGSGraphic?
    private var triangleGraphic: AGSGraphic?
    private var routeGraphic: AGSGraphic?
    private var currentFrameIndex = 0
    private var animationTimer: Timer?
    private var animationSpeed = 50
    private var orbitGeoElementCameraController: AGSOrbitGeoElementCameraController?
    private weak var planeStatsViewController: PlaneStatsViewController?
    private weak var missionSettingsViewController: MissionSettingsViewController?

    private var isAnimating = false {
        didSet {
            playBBI?.title = isAnimating ? "Pause" : "Play"
        }
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        // add the source code button item to the right of navigation bar
        (navigationItem.rightBarButtonItem as! SourceCodeBarButtonItem).filenames = ["Animate3DGraphicViewController", "MissionSettingsViewController", "CameraSettingsViewController", "PlaneStatsViewController", "OptionsTableViewController"]

        // map
        let map = AGSMap(basemapStyle: .arcGISStreets)
        mapView.map = map
        mapView.interactionOptions.isEnabled = false

        mapView.layer.borderColor = UIColor.white.cgColor
        mapView.layer.borderWidth = 2

        // hide attribution text for map view
        mapView.isAttributionTextVisible = false

        // Initalize scene with imagery basemap style.
        let scene = AGSScene(basemapStyle: .arcGISImagery)

        // assign scene to scene view
        sceneView.scene = scene

        /// The url of the Terrain 3D ArcGIS REST Service.
        let worldElevationServiceURL = URL(string: "https://elevation3d.arcgis.com/arcgis/rest/services/WorldElevation3D/Terrain3D/ImageServer")!
        // elevation source
        let elevationSource = AGSArcGISTiledElevationSource(url: worldElevationServiceURL)

        // surface
        let surface = AGSSurface()
        surface.elevationSources.append(elevationSource)
        scene.baseSurface = surface

        // graphics overlay for scene view
        sceneGraphicsOverlay.sceneProperties?.surfacePlacement = .absolute
        sceneView.graphicsOverlays.add(sceneGraphicsOverlay)

        // renderer for scene graphics overlay
        let renderer = AGSSimpleRenderer()

        // expressions
        renderer.sceneProperties?.headingExpression = "[HEADING]"
        renderer.sceneProperties?.pitchExpression = "[PITCH]"
        renderer.sceneProperties?.rollExpression = "[ROLL]"

        // set renderer on the overlay
        sceneGraphicsOverlay.renderer = renderer

        // graphics overlay for map view
        mapView.graphicsOverlays.add(mapGraphicsOverlay)

        // renderer for map graphics overlay
        let renderer2D = AGSSimpleRenderer()
        renderer2D.rotationExpression = "[ANGLE]"
        mapGraphicsOverlay.renderer = renderer2D

        // route graphic
        let lineSymbol = AGSSimpleLineSymbol(style: .solid, color: .blue, width: 1)
        let routeGraphic = AGSGraphic(geometry: nil, symbol: lineSymbol, attributes: nil)
        self.routeGraphic = routeGraphic
        mapGraphicsOverlay.graphics.add(routeGraphic)

        addPlane2D()

        // add the plane model
        addPlane3D()

        // setup camera to follow the plane
        setupCamera()

        // select the first mission by default
        changeMissionAction()
    }

    private func addPlane2D() {
        let triangleSymbol = AGSSimpleMarkerSymbol(style: .triangle, color: .red, size: 10)
        let triangleGraphic = AGSGraphic(geometry: nil, symbol: triangleSymbol, attributes: nil)
        self.triangleGraphic = triangleGraphic
        mapGraphicsOverlay.graphics.add(triangleGraphic)
    }

    private func addPlane3D() {
        // model symbol
        let planeModelSymbol = AGSModelSceneSymbol(name: "Bristol", extension: "dae", scale: 20)
        planeModelSymbol.anchorPosition = .center

        // arbitrary geometry for time being, the geometry will update with animation
        let point = AGSPoint(x: 0, y: 0, z: 0, spatialReference: .wgs84())

        // create graphic for the model
        let planeModelGraphic = AGSGraphic()
        self.planeModelGraphic = planeModelGraphic
        planeModelGraphic.geometry = point
        planeModelGraphic.symbol = planeModelSymbol

        // add graphic to the graphics overlay
        sceneGraphicsOverlay.graphics.add(planeModelGraphic)
    }

    private func setupCamera() {
        guard let planeModelGraphic = planeModelGraphic else {
            return
        }

        // AGSOrbitGeoElementCameraController to follow plane graphic
        // initialize object specifying the target geo element and distance to keep from it
        let orbitGeoElementCameraController = AGSOrbitGeoElementCameraController(targetGeoElement: planeModelGraphic, distance: 1000)
        self.orbitGeoElementCameraController = orbitGeoElementCameraController

        // set camera to align its heading with the model
        orbitGeoElementCameraController.isAutoHeadingEnabled = true

        // will keep the camera still while the model pitches or rolls
        orbitGeoElementCameraController.isAutoPitchEnabled = false
        orbitGeoElementCameraController.isAutoRollEnabled = false

        // min and max distance values between the model and the camera
        orbitGeoElementCameraController.minCameraDistance = 500
        orbitGeoElementCameraController.maxCameraDistance = 8000

        // set the camera controller on scene view
        sceneView.cameraController = orbitGeoElementCameraController
    }

    private func loadMissionData(_ name: String) {
        // get the path of the specified file in the bundle
        if let path = Bundle.main.path(forResource: name, ofType: nil) {
            // get content of the file
            if let content = try? String(contentsOfFile: path) {
                // split content into array of lines separated by new line character
                // each line is one frame
                let lines = content.components(separatedBy: CharacterSet.newlines)

                // create a frame object for each line
                frames = lines.map { (line) -> Frame in
                    let details = line.components(separatedBy: ",")
                    precondition(details.count == 6)

                    let position = AGSPoint(x: Double(details[0])!,
                                            y: Double(details[1])!,
                                            z: Double(details[2])!,
                                            spatialReference: .wgs84())

                    // load position, heading, pitch and roll for each frame
                    return Frame(position: position,
                                 heading: Measurement(value: Double(details[3])!, unit: UnitAngle.degrees),
                                 pitch: Measurement(value: Double(details[4])!, unit: UnitAngle.degrees),
                                 roll: Measurement(value: Double(details[5])!, unit: UnitAngle.degrees))
                }
            }
        } else {
            print("Mission file not found")
        }
    }

    private func startAnimation() {
        // invalidate timer to stop previous ongoing animation
        self.animationTimer?.invalidate()

        // duration or interval
        let duration = 1 / Double(animationSpeed)

        // new timer
        let animationTimer = Timer(timeInterval: duration, repeats: true) { [weak self] _ in
            self?.animate()
        }
        self.animationTimer = animationTimer
        RunLoop.main.add(animationTimer, forMode: .common)
    }

    private func animate() {
        // validations
        guard !frames.isEmpty,
            let planeModelGraphic = planeModelGraphic,
            let triangleGraphic = triangleGraphic else {
            return
        }

        // if animation is complete
        if currentFrameIndex >= frames.count {
            // invalidate timer
            animationTimer?.invalidate()

            // update state
            isAnimating = false

            // reset index
            currentFrameIndex = 0

            return
        }

        // else get the frame
        let frame = frames[currentFrameIndex]

        // update the properties on the model
        planeModelGraphic.geometry = frame.position
        planeModelGraphic.attributes["HEADING"] = frame.heading.value
        planeModelGraphic.attributes["PITCH"] = frame.pitch.value
        planeModelGraphic.attributes["ROLL"] = frame.roll.value

        // 2D plane
        triangleGraphic.geometry = frame.position

        // set viewpoint for map view
        let viewpoint = AGSViewpoint(center: frame.position, scale: 100000, rotation: 360 + frame.heading.value)
        mapView.setViewpoint(viewpoint)

        // update progress
        missionSettingsViewController?.progress = Float(currentFrameIndex) / Float(frames.count)

        // update stats
        planeStatsViewController?.frame = frame

        // increment current frame index
        currentFrameIndex += 1
    }

    // MARK: - Actions

    @IBAction func changeMissionAction() {
        // invalidate timer
        animationTimer?.invalidate()

        // set play button
        isAnimating = false

        // new mission name
        let missionFileName = missionFileNames[selectedMissionIndex]
        loadMissionData(missionFileName)

        // create a polyline from position in each frame to be used as path
        let points = frames.map { (frame) -> AGSPoint in
            return frame.position
        }

        let polylineBuilder = AGSPolylineBuilder(points: points)
        routeGraphic?.geometry = polylineBuilder.toGeometry()

        // set current frame to zero
        currentFrameIndex = 0

        // animate to first frame
        animate()
    }

    @IBAction func playAction(sender: UIBarButtonItem) {
        if isAnimating {
            animationTimer?.invalidate()
        } else {
            startAnimation()
        }

        isAnimating.toggle()
    }

    // MARK: - Navigation

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        // dismiss any shown view controllers
        dismiss(animated: false)

        if let controller = segue.destination as? CameraSettingsViewController {
            controller.orbitGeoElementCameraController = orbitGeoElementCameraController

            // pop over settings
            controller.presentationController?.delegate = self

            // preferred content size
            if traitCollection.horizontalSizeClass == .regular,
                traitCollection.verticalSizeClass == .regular {
                controller.preferredContentSize = CGSize(width: 300, height: 380)
            } else {
                controller.preferredContentSize = CGSize(width: 300, height: 250)
            }
        } else if let planeStatsViewController = segue.destination as? PlaneStatsViewController {
            self.planeStatsViewController = planeStatsViewController
            let frame = frames[currentFrameIndex]
            // Update stats.
            planeStatsViewController.frame = frame
            // pop over settings
            planeStatsViewController.presentationController?.delegate = self
        } else if let navController = segue.destination as? UINavigationController,
            let controller = navController.viewControllers.first as? MissionSettingsViewController {
            self.missionSettingsViewController = controller
            // initial values
            controller.missionFileNames = missionFileNames
            controller.selectedMissionIndex = selectedMissionIndex
            controller.animationSpeed = animationSpeed
            controller.progress = Float(currentFrameIndex) / Float(frames.count)

            // pop over settings
            navController.presentationController?.delegate = self
            controller.preferredContentSize = CGSize(width: 300, height: 200)
            controller.delegate = self
        }
    }
}

extension Animate3DGraphicViewController: MissionSettingsViewControllerDelegate {
    func missionSettingsViewController(_ missionSettingsViewController: MissionSettingsViewController, didSelectMissionAtIndex index: Int) {
        selectedMissionIndex = index
        changeMissionAction()
    }

    func missionSettingsViewController(_ missionSettingsViewController: MissionSettingsViewController, didChangeSpeed speed: Int) {
        animationSpeed = speed

        if isAnimating {
            animationTimer?.invalidate()
            startAnimation()
        }
    }
}

extension Animate3DGraphicViewController: UIAdaptivePresentationControllerDelegate {
    func adaptivePresentationStyle(for controller: UIPresentationController, traitCollection: UITraitCollection) -> UIModalPresentationStyle {
        // for popover or non modal presentation
        return .none
    }
}

struct Frame {
    let position: AGSPoint
    let heading: Measurement<UnitAngle>
    let pitch: Measurement<UnitAngle>
    let roll: Measurement<UnitAngle>

    init(position: AGSPoint, heading: Measurement<UnitAngle>, pitch: Measurement<UnitAngle>, roll: Measurement<UnitAngle>) {
        self.position = position
        self.heading = heading
        self.pitch = pitch
        self.roll = roll
    }

    var altitude: Measurement<UnitLength> {
        return Measurement(value: position.z, unit: UnitLength.meters)
    }
}