Integrate iOS device camera and motion features to produce augmented reality experiences in your app or game using ARKit.

ARKit Documentation

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ARKit delegate code broken by Swift 6
I'm porting over some code that uses ARKit to Swift 6 (with Complete Strict Concurrency Checking enabled). Some methods on ARSCNViewDelegate, namely Coordinator.renderer(_:didAdd:for:) among at least one other is causing a consistent crash. On Swift 5 this code works absolutely fine. The above method consistently crashes with _dispatch_assert_queue_fail. My assumption is that in Swift 6 a trap has been inserted by the compiler to validate that my downstream code is running on the main thread. In Implementing a Main Actor Protocol That’s Not @MainActor, Quinn “The Eskimo!” seems to address scenarios of this nature with 3 proposed workarounds yet none of them seem feasible here. For #1, marking ContentView.addPlane(renderer:node:anchor:) nonisolated and using @preconcurrency import ARKit compiles but still crashes :( For #2, applying @preconcurrency to the ARSCNViewDelegate conformance declaration site just yields this warning: @preconcurrency attribute on conformance to 'ARSCNViewDelegate' has no effect For #3, as Quinn recognizes, this is a non-starter as ARSCNViewDelegate is out of our control. The minimal reproducible set of code is below. Simply run the app, scan your camera back and forth across a well lit environment and the app should crash within a few seconds. Switch over to Swift Language Version 5 in build settings, retry and you'll see the current code works fine. import ARKit import SwiftUI struct ContentView: View { @State private var arViewProxy = ARSceneProxy() private let configuration: ARWorldTrackingConfiguration @State private var planeFound = false init() { configuration = ARWorldTrackingConfiguration() configuration.worldAlignment = .gravityAndHeading configuration.planeDetection = [.horizontal] } var body: some View { ARScene(proxy: arViewProxy) .onAddNode { renderer, node, anchor in addPlane(renderer: renderer, node: node, anchor: anchor) } .onAppear { arViewProxy.session.run(configuration) } .onDisappear { arViewProxy.session.pause() } .overlay(alignment: .top) { if !planeFound { Text("Slowly move device horizontally side to side to calibrate") } else { Text("Plane found!") .bold() .foregroundStyle(.green) } } } private func addPlane(renderer: SCNSceneRenderer, node: SCNNode, anchor: ARAnchor) { guard let planeAnchor = anchor as? ARPlaneAnchor, let device = renderer.device, let planeGeometry = ARSCNPlaneGeometry(device: device) else { return } planeFound = true planeGeometry.update(from: planeAnchor.geometry) let material = SCNMaterial() material.isDoubleSided = true material.diffuse.contents = UIColor.white.withAlphaComponent(0.65) planeGeometry.materials = [material] let planeNode = SCNNode(geometry: planeGeometry) node.addChildNode(planeNode) } } struct ARScene { private(set) var onAddNodeAction: ((SCNSceneRenderer, SCNNode, ARAnchor) -> Void)? private let proxy: ARSceneProxy init(proxy: ARSceneProxy) { self.proxy = proxy } func onAddNode( perform action: @escaping (SCNSceneRenderer, SCNNode, ARAnchor) -> Void ) -> Self { var view = self view.onAddNodeAction = action return view } } extension ARScene: UIViewRepresentable { func makeUIView(context: Context) -> ARSCNView { let arView = ARSCNView() arView.delegate = context.coordinator arView.session.delegate = context.coordinator proxy.arView = arView return arView } func updateUIView(_ uiView: ARSCNView, context: Context) { context.coordinator.onAddNodeAction = onAddNodeAction } func makeCoordinator() -> Coordinator { Coordinator() } } extension ARScene { class Coordinator: NSObject, ARSCNViewDelegate, ARSessionDelegate { var onAddNodeAction: ((SCNSceneRenderer, SCNNode, ARAnchor) -> Void)? func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) { onAddNodeAction?(renderer, node, anchor) } } } @MainActor class ARSceneProxy: NSObject, @preconcurrency ARSessionProviding { fileprivate var arView: ARSCNView! @objc dynamic var session: ARSession { arView.session } } Any help is greatly appreciated!
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627
Oct ’24
Reality Composer Project and Xcode 16
After upgrading to Xcode 16 my app, which utilizes imported project files from my iPad's Reality Composer app, now has two issues that I have found so far. I am using an ARView as a UIViewRepresentable with SwiftUI. (Prior to upgading to Xcode 16 everything worked well.) First, there are now several duplicate rcp_export.usdz resources in the "Copy Bundle Resources" build phase section. Even though each file is in a separate folder with a unique UUID, it was causing a compile error saying there are duplicate files. I was able to open the RC project folder and delete the older rcp_project versions which now allows the app to compile. I mention it as it may or may not be related to the second issue. Second, Xcode isn't generating the project code for rcproject, so when I call the RCProject.loadSceneAsync function I am getting an error that says "Cannot find 'RCProject' in scope"
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933
Jan ’25
Xcode 16 cannot load AR scenes from .rcproject files
Ever since updating to Xcode 16 my AR app doesn't compile, because Xcode doesn't recognize the .rcproject files used to load the AR experiences in iOS app. The .rcproject files were authored in Reality Composer on iPadOS. The expected behavior is described in this official Apple documentation article: https://developer.apple.com/documentation/realitykit/loading-entities-from-a-file How do I submit a ticket to Apple?
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550
Nov ’24
Barcode Detection Enterprise API
I am attempting to use the Barcode Detection enterprise API. I have the necessary entitlements and license file. I'm following the sample code online, and whenever I attempt to run the barcode detection using arKitSession.run I get the following error message: ar_barcode_detection_provider_t <0x300d82130>: Failed to run provider with transient error code: 1 It obviously isn't running the barcode detection, even though it's running in an immersive space in mixed mode. Any idea what might be going on?
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1.6k
Dec ’24
RoomCaptureSession persistence, ARSession pause broken?
Hi all, Our app allows a user to scan a room and then save that scan on a separate view, followed by additional scans. We're looking into allowing room combining via CapturedStructure, so we need rooms to be scanned in the same ARWorldMap without necessarily needing to re-localize in the same session. This should fit within the first scenario that Apple described. The only way I have found that allows our requirements is to save RoomCaptureView and to re-use that RoomCaptureView whenever we need to start a session again. This creates a number of other issues, and ideally, we wouldn't need to save a View in something like a singleton. We are using captureSession.stop(pauseARSession: false). Additionally, if we use the same RoomCaptureView and an error occurs during the scanning process, we can't get the instructions overlay to appear again if we reuse this view (specifically, the instructions in the middle of the view that state "Move device to start"). It's as if the instructions are completely removed and scanning is stuck on an error state if an error occurs. These instructions also seem to be separate from the instructions we can grab from RoomCaptureViewDelegate via didProvide instruction: RoomCaptureSession.Instruction), so we can't use that either. There's a couple subviews that seem relevant to this: RoomCaptureCoachingOverlayView and ARGlyphView - but both are not public, so we can't force them to appear. Also attempted a number of other things to try to get these subviews to appear, such as layoutIfNeeded(). Saving the ARSession and using it in let roomCaptureView = RoomCaptureView(frame: viewBounds, arSession: arSession) where we're creating a new view with the same ARSession seems much more ideal as that solves the above issues, but we run into another issue: world tracking seems to be completely lost when a new RoomCaptureView (and thus a new RoomCaptureSession) is started, even with the same already started ARSession, almost as if captureSession.stop(pauseARSession: false) doesn't work as described. Is there any way around needing to use the same RoomCaptureView or RoomCaptureSession for subsequent scans in the same session without needing to re-localize via ARWorldMap loading? Is there a way to force the guiding instructions to appear?
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541
Nov ’24
How do we author a "reality file" like the ones on Apple's Gallery?
How do we author a Reality File like the ones under Examples with animations at https://developer.apple.com/augmented-reality/quick-look/ ?? For example, "The Hab" : https://developer.apple.com/augmented-reality/quick-look/models/hab/hab_en.reality Tapping on various buttons in this experience triggers various complex animations. I don't see any way to accomplish this in Reality Composer. And I don't see any way to export/compile to a "reality file" from within Xcode. How can I use multiple animations within a single GLTF file? How can I set up multiple "tap target" on a single object, where each one triggers a different action? How do we author something similar? What tools do we use? Thanks
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1.9k
Nov ’24
Can not remove final World Anchor
I’ve been having some issues removing anchors. I can add anchors with no issue. They will be there the next time I run the scene. I can also get updates when ARKit sends them. I can remove anchors, but not all the time. The method I’m using is to call removeAnchor() on the data provider. worldTracking.removeAnchor(forID: uuid) // Yes, I have also tried `removeAnchor(_ worldAnchor: WorldAnchor)` This works if there are more than one anchor in a scene. When I’m down to one remaining anchor, I can remove it. It seems to succeed (does not raise an error) but the next time I run the scene the removed anchor is back. This only happens when there is only one remaining anchor. do { // This always run, but it doesn't seem to "save" the removal when there is only one anchor left. try await worldTracking.removeAnchor(forID: uuid) } catch { // I have never seen this block fire! print("Failed to remove world anchor \(uuid) with error: \(error).") } I posted a video on my website if you want to see it happening. https://stepinto.vision/labs/lab-051-issues-with-world-tracking/ Here is the full code. Can you see if I’m doing something wrong? Is this a bug? struct Lab051: View { @State var session = ARKitSession() @State var worldTracking = WorldTrackingProvider() @State var worldAnchorEntities: [UUID: Entity] = [:] @State var placement = Entity() @State var subject : ModelEntity = { let subject = ModelEntity( mesh: .generateSphere(radius: 0.06), materials: [SimpleMaterial(color: .stepRed, isMetallic: false)]) subject.setPosition([0, 0, 0], relativeTo: nil) let collision = CollisionComponent(shapes: [.generateSphere(radius: 0.06)]) let input = InputTargetComponent() subject.components.set([collision, input]) return subject }() var body: some View { RealityView { content in guard let scene = try? await Entity(named: "WorldTracking", in: realityKitContentBundle) else { return } content.add(scene) if let placementEntity = scene.findEntity(named: "PlacementPreview") { placement = placementEntity } } update: { content in for (_, entity) in worldAnchorEntities { if !content.entities.contains(entity) { content.add(entity) } } } .modifier(DragGestureImproved()) .gesture(tapGesture) .task { try! await setupAndRunWorldTracking() } } var tapGesture: some Gesture { TapGesture() .targetedToAnyEntity() .onEnded { value in if value.entity.name == "PlacementPreview" { // If we tapped the placement preview cube, create an anchor Task { let anchor = WorldAnchor(originFromAnchorTransform: value.entity.transformMatrix(relativeTo: nil)) try await worldTracking.addAnchor(anchor) } } else { Task { // Get the UUID we stored on the entity let uuid = UUID(uuidString: value.entity.name) ?? UUID() do { try await worldTracking.removeAnchor(forID: uuid) } catch { print("Failed to remove world anchor \(uuid) with error: \(error).") } } } } } func setupAndRunWorldTracking() async throws { if WorldTrackingProvider.isSupported { do { try await session.run([worldTracking]) for await update in worldTracking.anchorUpdates { switch update.event { case .added: let subjectClone = subject.clone(recursive: true) subjectClone.isEnabled = true subjectClone.name = update.anchor.id.uuidString subjectClone.transform = Transform(matrix: update.anchor.originFromAnchorTransform) worldAnchorEntities[update.anchor.id] = subjectClone print("🟢 Anchor added \(update.anchor.id)") case .updated: guard let entity = worldAnchorEntities[update.anchor.id] else { print("No entity found to update for anchor \(update.anchor.id)") return } entity.transform = Transform(matrix: update.anchor.originFromAnchorTransform) print("🔵 Anchor updated \(update.anchor.id)") case .removed: worldAnchorEntities[update.anchor.id]?.removeFromParent() worldAnchorEntities.removeValue(forKey: update.anchor.id) print("🔴 Anchor removed \(update.anchor.id)") if let remainingAnchors = await worldTracking.allAnchors { print("Remaining Anchors: \(remainingAnchors.count)") } } } } catch { print("ARKit session error \(error)") } } } }
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151
May ’25
What causes »ARSessionDelegate is retaining X ARFrames« console warning?
Hi, since iOS 15 I've repeatedly noticed the console warning »ARSessionDelegate is retaining X ARFrames. This can lead to future camera frames being dropped« even for rather simple projects using RealityKit and ARKit. Could someone from the ARKit team please elaborate what causes this warning and what can be done to avoid it? If I remember correctly I didn't even assign an ARSessionDelegate. Thank you!
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3.3k
Feb ’25
Getting to MeshAnchor.MeshClassification from MeshAnchor?
I am working with MeshAnchors, and I am having troubles getting to the classification of the triangles/faces. This post references the MeshAnchor.Geometry, and that struct does have a property named "classifications", but it is of type GeometrySource. I cannot find any classification information in GeometrySource. Am I missing something there? I think I am looking for something of type MeshAnchor.MeshClassification, but I cannot find any structs with this as a property.
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1.2k
Feb ’25
RoomPlan Framework v2 - Stairs missing
Hello Community, I'm encountering an issue with the latest iOS 17 update, specifically related to RoomPlan version-2. In iOS 16, when using RoomPlan version-1, we were able to display stairs in our app. However, after upgrading to iOS 17 and implementing RoomPlan version-2, the stairs are no longer visible. Despite thorough investigation, I couldn't find any option within the code to show or hide stairs, or any other objects for that matter. It seems like a specific issue with the update rather than a coding error on our part. Has anyone else encountered a similar problem? If so, I would greatly appreciate any insights or solutions you might have. It's crucial for our app functionality to have stairs displayed accurately, and we're currently at a loss on how to address this issue. Thank you in advance for any assistance you can provide. Best regards
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1w
RealityKit/ARKit Environment Texturing broken on iOS 18
Devices running iOS 18 using RealityKit do not seem to receive lighting supplied via ARKit Environment Texturing (https://developer.apple.com/documentation/arkit/arworldtrackingconfiguration/2977509-environmenttexturing). Instead just a default IBL is used by RealityKit. This happens with RealityView as well as ARView. It also happens when I explicitly opt-in to environment texturing: let worldTrackingConfig = ARWorldTrackingConfiguration() worldTrackingConfig.environmentTexturing = .automatic arView.session.run(worldTrackingConfig) Even the Xcode AR Template has this issue. I'm attaching a screenshot of the sample app running on iOS 18 where it's broken and from iOS 17 where it works as expected. I hope this can get resolved quickly since I see it as a major regression. Feedback ID: FB15091335 UPDATE: It works on my older iPhone XS (iOS 18 22A5282m) Broken on iPad Pro (11-inch) (3rd generation) (iPadOS 18.0 (22A5350a)) Maybe it's related to LiDAR? Thank you! iOS 17 (works): iOS 18 (broken):
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988
Jan ’25
Issue: ARKit Camera Frame Provider Not Authorized in visionOS App
I’m developing a visionOS app using EnterpriseKit, and I need access to the main camera for QR code detection. I’m using the ARKit CameraFrameProvider and ARKitSession to capture frames, but I’m encountering this error when trying to start the camera stream: ar_camera_frame_provider_t: Failed to start camera stream with error: <ar_error_t Error Domain=com.apple.arkit Code=100 "App not authorized."> Context: VisionOS using EnterpriseKit for camera access and QR code scanning. My Info.plist includes necessary permissions like NSCameraUsageDescription and NSWorldSensingUsageDescription. I’ve added the com.apple.developer.arkit.main-camera-access.allow entitlement as per the official documentation here. My app is allowed camera access as shown in the logs (Authorization status: [cameraAccess: allowed]), but the camera stream still fails to start with the “App not authorized” error. I followed Apple’s WWDC 2024 sample code for accessing the main camera in visionOS from this session. Sample of My Code: import ARKit import Vision class QRCodeScanner: ObservableObject { private var arKitSession = ARKitSession() private var cameraFrameProvider = CameraFrameProvider() private var pixelBuffer: CVPixelBuffer? init() { Task { await requestCameraAccess() } } private func requestCameraAccess() async { await arKitSession.queryAuthorization(for: [.cameraAccess]) do { try await arKitSession.run([cameraFrameProvider]) } catch { print("Failed to start ARKit session: \(error)") return } let formats = CameraVideoFormat.supportedVideoFormats(for: .main, cameraPositions: [.left]) guard let cameraFrameUpdates = cameraFrameProvider.cameraFrameUpdates(for: formats[0]) else { return } Task { for await cameraFrame in cameraFrameUpdates { guard let mainCameraSample = cameraFrame.sample(for: .left) else { continue } self.pixelBuffer = mainCameraSample.pixelBuffer // QR Code detection code here } } } } Things I’ve Tried: Verified entitlements in both Info.plist and .entitlements files. I have added the com.apple.developer.arkit.main-camera-access.allow entitlement. Confirmed camera permissions in the privacy settings. Followed the official documentation and WWDC 2024 sample code. Checked my provisioning profile to ensure it supports ARKit camera access. Request: Has anyone encountered this “App not authorized” error when accessing the main camera via ARKit in visionOS using EnterpriseKit? Are there additional entitlements or provisioning profile configurations I might be missing? Any help would be greatly appreciated! I haven't seen any official examples using new API for main camera access and no open source examples either.
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1.1k
Oct ’24
RGB-D and Point Clouds in visionOS
Dear all, We are building an XR application demonstrating our research on open-vocabulary 3D instance segmentation for assistive technology. We intend on bringing it to visionOS using the new Enterprise APIs. Our method was trained on datasets resembling ScanNet which contain the following: localized (1) RGB camera frames (2) with Depth (3) and camera intrinsics (4) point cloud (5) I understand, we can query (1), (2), and (4) from the CameraFrameProvider. As for (3) and (4), it is unclear to me if/how we can obtain that data. In handheld ARKit, this example project demos how the depthMap can be used to simulate raw point clouds. However, this property doesn't seem to be available in visionOS. Is there some way for us to obtain depth data associated with camera frames? "Faking" depth data from the SceneReconstructionProvider-generated meshes is too coarse for our method. I hope I'm just missing some detail and there's some way to configure CameraFrameProvider to also deliver depth and/or point clouds. Thanks for any help or pointer in the right direction! ~ Alex
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610
Oct ’24
Cannot find the entitlement of Enterprise API for Vision pro
We are developing VisionOS app now, we have applied the Enterprise API for visionOS, including Main Camera Access for Vision Pro, and already get the "Enterprise.license" in the mail apple sent us, we use the developer account import the license file into Xcode: but in Xcode, we cannot find the entitlement of Enterprise API: if we put com.apple.developer.arkit.main-camera-access.allow into Entitlement file of the project manually,Xcode will alarm: and we find that the app itself dont have "Additional Capabilities" which include the Enterprise API: what should we do to have the entitlement file for the Enterprise API, so we can use the enterprise API?
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757
Oct ’24
Issue with tracking multiple images using ARKit on VisionOS
We are using the ARKit image tracking feature on visionOS 2.0 with three pre-registered images. The image tracking works, but only one image is actively tracked at a time. When more than one target image is visible to the camera, it has difficulty detecting and tracking the other images. Is this the expected behavior in visionOS, or is there something we need to do to resolve this issue?
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452
Mar ’25
Attaching VideoMaterial to DockingRegion
I have a VideoMaterial inside a RealityView and want to attach this to a DockingRegion inside an immersive environment. It appears that adding the VideoMaterial entity as a child of the docking region somewhat works, but there are no lighting effects (specular, diffuse) from the playing video. So essentially, how can you add a VideoMaterial to a DockingRegion and achieve the same reflections/behavior as using AVPlayerViewController. The latter is not an option as I need custom controls.
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550
Dec ’24
raycast during RoomCaptureSession
I created an app where the user: first scans a room using RoomCaptureView (RoomPlan) then taps on physical elements (objects, walls...) using an ARView to record some 3d positions I can handle taps in an ARView using a UITapGestureRecognizer and the ARView raycast(from:, allowing:, alignment:) method. This works fine, so I thought I could do the same using the ARView used by RoomCaptureView., so the user can scan a room and record some 3d positions at the same time. Sadly, this approach does not work, as the raycast method always returns nil. What I actually need is mapping a tap on screen to a real-world position during RoomCaptureSession. Does anyone know how to do this?
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565
Nov ’24
ARView vs RealityView (iOS, iPadOS)
I have been digging through the docs and the developer videos, and I have noticed a mention to RealityView having som potential limitations with anchors and world tracking. However, I haven’t been able to locate my answers. Does anyone know (or point me to) if RealityView supports everything ARView does, and if not what are the difference? I was fooling around with RealityView today with a simple plane anchor, and the stability of that anchor didn’t seem to be as steady as I recall ARView being In the past on iPhone. I’m trying to determine if I should be rolling over into RealityView or stay with ARView on this little educational project. I would imagine the answer is to go RealityView, but I want to make sure I’m not setting myself up for failure based on any current limitations For anchors and world data.
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855
Jan ’25