This post documents an issue I reported in feedback FB19610114 and see if anyone knows of a workaround. Here is a copy of the feedback.
Short version
Manipulation (SwiftUI OR RealityKit) fails to translate entities after changing rooms. By changing rooms, I mean a human wearing an Apple Vision Pro leaving one room and entering another room. Once this issue occurs, it impacts all apps that use these features. A device restart is the only solution I have to fix it.
Feedback FB19610114
This is an odd one. I'm using the new Manipulation Component in visionOS 26. Most of the time this works well. Sometime it stops working and when it does the only way to get it working again is to reboot the headset.
When this happens, I can continue to rotate and scale items, but translation no longer works. It is as if the item is stuck to a fixed point in the parent scene (window, volume, etc). When this bug occurs, it affects every app across the entire operating system that is using manipulation, including the RealityKit component AND the SwiftUI version. This is not limited to one app and is not limited to apps that I am working on. Once this error occurs, it affects literally any application across the operating system that is using this API, including apps from Apple.
I won't speculate on the cause of this, but I do know of one way where I can always get it to happen.
Here is how to reproduce it:
Make an Xcode project with a single entity that uses the Manipulation Component. There is no need to customize the configuration of this component. The default implementation will work.
Build and run this app on device. You can keep running from device or quit and launch the app like normal on device.
Open the app and manipulate the entity - it should work as expected.
Physically walk into another room. It is vital that you leave the current room that you are in and enter a different room entirely.
Use the digital crown to recenter your view and bring your window or volume to you.
Test the manipulation on the entity again - it should still be working as expected at this point.
Physically, move yourself and your headset into the original room where you started.
Use the digital crown to recenter your view and bring your window or volume to you.
Test the manipulation on the entity again - you should now see the issue.
When I follow the steps above, then 100% of the time manipulation translation stops working at this point. It will impact any application using this API. The only way to fix it is to restart my headset.
A few points to keep in mind
It does not matter if an app is actively being run from Xcode.
When this occurs, it impacts every single app, not just one.
When this occurs, rotation and scaling continue to work, but the entity/view cannot be translated.
This impacts BOTH the SwiftUI version and the RealityKit version.
When this occurs, the only way to "fix" it is to reboot the device.
Selecting any option will automatically load the page
Post
Replies
Boosts
Views
Activity
The landing page for visionOS 26 mentions
The Unified Coordinate Conversion API makes moving views and entities between scenes straightforward — even between views and ARKit accessory anchors.
This WWDC session very briefly shows a single example of using this, but with no context. For example, they discuss a way to tell the distance between a Model3D and an entity in a RealityView. But they don't provide any details for how they are referencing the entity (bolts in the slide).
The session used the BOT-anist example project that we saw in visionOS 2, but the version on in the Sample Code library has not been updated with these examples.
I was able to put together a simple example where we can get the position of a window relative to the world origin. It even updates when the user recenters.
struct Lab080: View {
@State private var posX: Float = 0
@State private var posY: Float = 0
@State private var posZ: Float = 0
var body: some View {
GeometryReader3D { geometry in
VStack {
Text("Unified Coordinate Conversion")
.font(.largeTitle)
.padding(24)
VStack {
Text("X: \(posX)")
Text("Y: \(posY)")
Text("Z: \(posZ)")
}
.font(.title)
.padding(24)
}
.onGeometryChange3D(for: Point3D.self) { proxy in try! proxy
.coordinateSpace3D()
.convert(value: Point3D.zero, to: .worldReference)
} action: { old, new in
posX = Float(new.x)
posY = Float(new.y)
posZ = Float(new.z)
}
}
}
}
This is all that I've been able to figure out so far. What other features are included in this new Unified Coordinate Conversion?
Can we use this to get the position of one window relative to another? Can we use this to get the position of a view in a window relative to an entity in a RealityView, for example in a Volume or Immersive Space? What else can Unified Coordinate Conversion do?
Are there documentation pages that I'm missing? I'm not sure what to search for. Are there any Sample projects that use these features? Any additional information would be very helpful.
Topic:
Spatial Computing
SubTopic:
General
Do you retain a reference to your content (RealityViewContent) events? For example, the Manipulation Events docs from Apple use _ to discard the result. In theory the event should keep working while the content is alive.
_ = content.subscribe(to: ManipulationEvents.WillBegin.self) { event in
event.entity.components[ModelComponent.self]?.materials[0] = SimpleMaterial(color: .blue, isMetallic: false)
}
_ = content.subscribe(to: ManipulationEvents.WillEnd.self) { event in
event.entity.components[ModelComponent.self]?.materials[0] = SimpleMaterial(color: .red, isMetallic: false)
}
We could store these events in state. I've seen this in a few samples and apps.
@State var beginSubscription: EventSubscription?
...
beginSubscription = content.subscribe(to: ManipulationEvents.WillBegin.self) { event in
event.entity.components[ModelComponent.self]?.materials[0] = SimpleMaterial(color: .blue, isMetallic: false)
}
The main advantage I see is that we can be more explicit about when we remove the event. Are there other reasons to keep a reference to these events?
At a recent community meeting we were wondering how Apple creates this soft-edge effect around the occlusion cutouts. We see this effect on keyboard cutouts, iPhone cutouts, and in progressive spaces.
An example: Notice the soft edged around the occlusion cutout for the keyboard
One of our members created some Shader Graph materials to explore soft edges. These work by sending data into the opacity channel of the PreviewSurface node.
Unfortunately, the Occlusion Surface nodes lack any sort of input. If you know how to blend these concepts with RealityKit Occlusion, please let us know!
We can add ornaments to popovers shown by PresentationComponent, but I’m not sure if we should.
While working on the editor for entities in a Volume-based app, I had the idea to add ornaments to the presented views. The entire app exists inside a volume. A user can tap a item to present a popoverUI to edit it. This is displayed using the new PresentationComponent in visionOS 26.
Ornaments have a new attachment anchor option this year: .parent().
.ornament(attachmentAnchor: .parent(.top), ornament: {...})
This works well in the Simulator. We can add ornaments around this popover view just like we would with a window.
Unfortunately, when I run this on device I get a different experience. Any part of the ornament that overlaps with the popover content isn’t rendered correctly. Sometimes it entirely disappears, other times it becomes partially transparent.
We could use content alignment to try to make sure the ornament doesn’t overlap the popover content.
.ornament(attachmentAnchor: .parent(.top), contentAlignment: .bottom, ornament: {...})
This works sometimes–but not all the time. It’s not clear if this is a bug or not, because I’m not sure if we are even supposed to be able to use ornaments in this way. Here is my hierarchy:
An app opens as a Volume
Volume presenting a RealityView, with its own ornament using .scene() anchor
Multiple Entities with Presentation Component show an edit view
The view uses .parent() anchor to add ornaments.
What makes me unsure is that other methods for drawing UI in RealityView don’t seem to work with ornaments. For example, if I add an attachment to show a view with the ornament–even when I use the .parent() anchor–the ornament is anchor to the volume, not the attachment view.
So what do we think? Is this a rendering bug? Are ornaments intended to work with attachments and presentations?
That title would have made a great WWDC Sessions. Unfortunately, it seems like nothing is new in Reality Composer Pro this year. I've noticed at all versions of the Xcode Beta this summer have shipped with Reality Composer Pro version 2.0. There have been slight bumps in the build number. I haven't found any new features or seen any documentation to indicate that anything has changed.
So the question is, what is the state of Reality Composer Pro? Should we continue to use this tool or start doing everything in code? A huge number of Sample Projects use Reality Composer Pro, so it seems like Apple is still using it even if they didn't update it this year.
Topic:
Spatial Computing
SubTopic:
Reality Composer Pro
During the WWDC Session called "Design widgets for visionOS" the presenter says:
You can choose whether the background of your widget participates in tinting. If you opted out, for example to preserve a photo or illustration, make sure it still looks good alongside the selected color palette.
Unfortunately, this session has no example code. Can someone point me to the correct way to do this? Is there a modifier we can use on views?
(reposting this in the correct topic/subtopic)
In Beta 1,2, and 3, we could pick up and inspect entities, bringing them closer while moving them outside of the bounds of a volume.
As of Beta 4, these entities are now clipped by the bounds of the volume. I'm not sure if this is a bug or an intended change, but I files a Feedback report (FB19005083). The release notes don't mention a change in behavior–at least not that I can find.
Is this an intentional change or a bug?
Here is a video that shows the issue.
https://youtu.be/ajBAaSxLL2Y
In the previous versions of visionOS 26, I could move these entities out of the volume and inspect them close up. Releasing would return them to the volume. Now they are clipped as soon as they reach the end of the volume.
I haven't had a chance to test with windows or with the SwiftUI modifier version of manipulation.
During the WWDC Session called "Design widgets for visionOS" the presenter says:
You can choose whether the background of your widget participates in tinting. If you opted out, for example to preserve a photo or illustration, make sure it still looks good alongside the selected color palette.
https://developer.apple.com/videos/play/wwdc2025/255
Unfortunately, this session has no example code. Can someone point me to the correct way to do this? Is there a modifier we can use on views?
When a user selects one the tint colors using the configuration screen, we would like to prevent some views from being tinted.
One of the most common ways to provide a window size in visionOS is to use the defaultSize scene modifier.
WindowGroup(id: "someID") {
SomeView()
}
.defaultSize(CGSize(width: 600, height: 600))
Starting in visionOS 26, using this has a side effect. visionOS 26 will restore windows that have been locked in place or snapped to surfaces. If a user has manually adjusted the size of a locked/snapped window, the users size is only restore in some cases.
Manual resize respected
Leaving a room and returning later
Taking the headset off and putting it back on later
Manual resize NOT respected
Device restart. In this case, the window is reopened where it was locked, but the size is set back to the values passed to defaultSize. The manual resizing adjustments the user has made are lost. This is counter to how all other windows and widgets work.
I reported this last month (FB18429638), but haven't heard back if this is a bug or intended behavior.
Questions
What is the best way to provide a default window size that will only be used when opening new windows–and not used during scene restoration?
Should we try to keep track of window size after users adjust them and save that somewhere?
If this is intended behavior, can someone please update the docs accordingly?
Starting in visionOS 26, users can snap windows to surfaces. These windows are locked in place and are later restored by visionOS. We can access the snapped data with surfaceSnappingInfo docs.
Users can also lock a free-floating (unsnapped) window from a context menu in the window controls.
Is there a way to tell when a window has been locked without being snapped to a surface?
Can we constrain or clamp translation with the new ManipulationComponent? For example, allow free movement within certain bounds.
I'm using SwiftData with CloutKit with a very simple app. Data syncs between iOS, iPadOS, and visionOS, but not macOS. From what I can tell, macOS is never getting CK messages unless I'm running the app from Xcode.
I can listen for the CK messages and show a line in a debug overlay. This works perfectly when I run from Xcode. I can see the notifications and see updates in my app. However, if I just launch the app outside of Xcode I will never see any changes or notifications. It is as if the Mac app never even tries to contact CloudKit.
Schema has been deployed in the CloudKit console. The app is based on the multi-platform Xcode template. Again, only the macOS version has this issue. Is there some extra permission or setting I need to set up in order to use CloudKit on macOS?
@State private var publisher = NotificationCenter.default.publisher(for: NSPersistentCloudKitContainer.eventChangedNotification).receive(on: DispatchQueue.main)
.onReceive(publisher) { notification in
// Listen for changes in CK events
if let userInfo = notification.userInfo,
let event = userInfo[NSPersistentCloudKitContainer.eventNotificationUserInfoKey] as? NSPersistentCloudKitContainer.Event {
let message = "CloudKit Sync: \(event.type.rawValue) - \(event.succeeded ? "Success" : "Failed") - \(event.description)"
// Store for UI display
syncNotifications.append(message)
if syncNotifications.count > 10 {
syncNotifications.removeFirst()
}
}
}
.overlay(alignment: .topTrailing) {
if !syncNotifications.isEmpty {
VStack(alignment: .leading) {
ForEach(syncNotifications, id: \.self) { notification in
Text(notification)
.padding(8)
}
}
.frame(width: 800, height: 500)
.cornerRadius(8)
.background(Color.secondary.opacity(0.2))
.padding()
.transition(.move(edge: .top))
}
}
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)")
}
}
}
}
I'm using ARKitSession and PlaneDetectionProvider to detect planes. I have a basics process to create an entity for each detected plane. Each one will get a random color for the material.
Each plane is sized based on the bounds of the anchor provided by ARKit.
let mesh = MeshResource.generatePlane(
width: anchor.geometry.extent.width,
depth: anchor.geometry.extent.height
)
Then I'm using this to position each entity.
entity.transform = Transform(matrix: anchor.originFromAnchorTransform)
This seems to be the right method, but many (not all) planes are not where they should be. The sizes look OK, but the X and Y positions off.
Take this large green plane on the wall. It should span the entire wall, but it is offset along the X position so that it is pushed to the left from where the center of the anchor is.
When I visualize surfaces using the Xcode debugging tools, that tool reports the planes where I'd expect them to be.
Can you see what I'm getting wrong here? Full code below
struct Example068: View {
@State var session = ARKitSession()
@State private var planeAnchors: [UUID: Entity] = [:]
@State private var planeColors: [UUID: Color] = [:]
var body: some View {
RealityView { content in
} update: { content in
for (_, entity) in planeAnchors {
if !content.entities.contains(entity) {
content.add(entity)
}
}
}
.task {
try! await setupAndRunPlaneDetection()
}
}
func setupAndRunPlaneDetection() async throws {
let planeData = PlaneDetectionProvider(alignments: [.horizontal, .vertical, .slanted])
if PlaneDetectionProvider.isSupported {
do {
try await session.run([planeData])
for await update in planeData.anchorUpdates {
switch update.event {
case .added, .updated:
let anchor = update.anchor
if planeColors[anchor.id] == nil {
planeColors[anchor.id] = generatePastelColor()
}
let planeEntity = createPlaneEntity(for: anchor, color: planeColors[anchor.id]!)
planeAnchors[anchor.id] = planeEntity
case .removed:
let anchor = update.anchor
planeAnchors.removeValue(forKey: anchor.id)
planeColors.removeValue(forKey: anchor.id)
}
}
} catch {
print("ARKit session error \(error)")
}
}
}
private func generatePastelColor() -> Color {
let hue = Double.random(in: 0...1)
let saturation = Double.random(in: 0.2...0.4)
let brightness = Double.random(in: 0.8...1.0)
return Color(hue: hue, saturation: saturation, brightness: brightness)
}
private func createPlaneEntity(for anchor: PlaneAnchor, color: Color) -> Entity {
let mesh = MeshResource.generatePlane(
width: anchor.geometry.extent.width,
depth: anchor.geometry.extent.height
)
var material = PhysicallyBasedMaterial()
material.baseColor.tint = UIColor(color)
let entity = ModelEntity(mesh: mesh, materials: [material])
entity.transform = Transform(matrix: anchor.originFromAnchorTransform)
return entity
}
}
Topic:
Spatial Computing
SubTopic:
ARKit