I tried to access my mac's front-facing camera using the code below. It worked in Swift Playgrounds but not in Xcode Playground. import AVFoundation import PlaygroundSupport //change uiview size dynamically, access video from avcapture class CameraView: UIViewController, AVCaptureVideoDataOutputSampleBufferDelegate{   var captureSession: AVCaptureSession?   var previewLayer: AVCaptureVideoPreviewLayer?   var previewView: UIView!   var output = AVCaptureVideoDataOutput() //video output   override func viewDidLoad(){     super.viewDidLoad()     setUpCamera()   }       func setUpCamera(){     captureSession = AVCaptureSession()     previewView = UIView(frame: UIScreen.main.bounds)     view.addSubview(previewView)     if let cameraDevice = AVCaptureDevice.default(for: .video){       do{         let input = try AVCaptureDeviceInput(device: cameraDevice)         if captureSession!.canAddInput(input){           captureSession!.addInput(input)         }         if captureSession!.canAddOutput(output){           output.setSampleBufferDelegate(self, queue: DispatchQueue(label: "videoQueue"))           captureSession!.addOutput(output)           previewLayer = AVCaptureVideoPreviewLayer(session: captureSession!)           previewLayer!.videoGravity = AVLayerVideoGravity.resize           previewLayer!.connection?.videoOrientation = .portrait           let viewLayer: CALayer = self.previewView.layer           view.bounds = UIScreen.main.bounds           previewLayer!.frame = view.bounds           viewLayer.addSublayer(self.previewLayer!)           captureSession!.startRunning()         }                 }catch{         print(error)       }             }   }     } PlaygroundPage.current.liveView = CameraView()