Hello, I'm building an AR image tracking application that detects some images and play video on each image. In most cases there is no problem, but some images are not detected. So, I tried these. when I init ARReferenceImage, I set the physicalWidth value to be same as the actual size. (It is 10cm) I change the contrast of image. But it didn't work very well. I would be very grateful if you could give me a small hint. Here is my code. ///Model struct PhotoCard {   var imageName: String   var image: UIImage   var videoURL: URL } struct TrackingItem {   var referenceImage: ARReferenceImage   var videoURL: URL } final class CameraModel { private let dataManger = DataManger.shared()   private func getPhotoCards() -> [PhotoCard] {     //get photocard from server return dataManger.getPhotoCards()   }       func trackingItems() -> [TrackingItem] {     let photocards: [PhotoCard] = getPhotoCards()     var items: [TrackingItem] = []           photocards.forEach { photoCard in       guard let cgImage = photoCard.image.cgImage else { return }       let referenceImage = ARReferenceImage(cgImage, orientation: .up, physicalWidth: 0.1)       referenceImage.name = photoCard.imageName       let item = TrackingItem(referenceImage: referenceImage, videoURL: photoCard.videoURL)       items.append(item)     }     return items   } } ///viewController import SceneKit import ARKit import AVFoundation import SpriteKit import RxSwift final class CameraViewController: VideoPlayerPresentableViewController, ARSCNViewDelegate { @IBOutlet private var sceneView: ARSCNView! private let model = CameraModel() private var data: [TrackingItem] = [] override func viewDidLoad() { super.viewDidLoad() setupSceneView() setupTrackingConfiguration() } override func viewWillDisappear(_ animated: Bool) { super.viewWillDisappear(animated) sceneView.session.pause() } private func setupSceneView() { sceneView.delegate = self let scene = SCNScene(named: "SceneAssets.scnassets/photocard.scn")! sceneView.scene = scene } private func setupTrackingConfiguration() { data = model.trackingItems() let configuration = ARImageTrackingConfiguration() configuration.isAutoFocusEnabled = true let trackingImages = data.map { $0.referenceImage } configuration.trackingImages = Set(trackingImages) configuration.maximumNumberOfTrackedImages = trackingImages.count sceneView.session.run(configuration) } func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) { guard let current = data.first(where: { $0.referenceImage.name == imageName }) else { return } let referenceImage = imageAnchor.referenceImage let planeGeometry = SCNPlane(width: referenceImage.physicalSize.width, height: referenceImage.physicalSize.height) let plane = SCNNode(geometry: planeGeometry) plane.transform = SCNMatrix4MakeRotation(-.pi/2, 1, 0, 0) let videoSceneAndPlayer = makeVideoSceneAndPlayer(with: current.videoURL) planeGeometry.materials.first?.diffuse.contents = videoSceneAndPlayer.0 node.addChildNode(plane) anchorAndPlayerMap[anchor] = videoSceneAndPlayer.1 model.updatePlayYN(of: current) } func renderer(_ renderer: SCNSceneRenderer, didUpdate node: SCNNode, for anchor: ARAnchor) { guard let imageAnchor = anchor as? ARImageAnchor, imageAnchor.isTracked == false else { return } sceneView.session.remove(anchor: anchor) } private func makeVideoSceneAndPlayer(with url: URL) -> (SKScene, AVPlayer) { let size = CGSize(width: 500, height: 500) let scene = SKScene(size: size) scene.scaleMode = .aspectFit let player = AVPlayer(url: url) let videoSpriteNode = SKVideoNode(avPlayer: player) videoSpriteNode.position = CGPoint(x: size.width/2, y: size.height/2) videoSpriteNode.size = size videoSpriteNode.yScale = -1 scene.addChild(videoSpriteNode) addObserver(of: player) player.play() return (scene, player) } }