Hi all,
I'm working on an ARKit-based iOS app where I need to accurately determine the direction the device is facing to localize objects in the real world. I'm using:
let config = ARWorldTrackingConfiguration()
config.worldAlignment = .gravityAndHeading
Thus, I would expect the world alignment to behave as given in the gravityAndHeading page.
The AR session is started after verifying that CLLocationManager.headingAccuracy <= 20, and the compass appears to be calibrated.
However, I'm seeing a major inconsistency:
When the rear camera is physically pointed toward true North, I would expect:
cameraTransform.columns.2.z ≈ -1 // (i.e. ARKit's -Z pointing North)
But instead, I'm consistently seeing:
cameraTransform.columns.2.z ≈ +0.97 // Implies camera is facing South
Meanwhile, the translation vector behaves as expected:
As I physically move North, cameraTransform.columns.3.z becomes more negative, matching the world’s +Z = South assumption.
For example, let's say I have the device in landscapeRight (or landscapeLeft for UIDeviceOrientation). Let's say the device rear camera is pointing towards True North, and I start moving towards True North. I get something like this:
Camera Transform = simd_float4x4(
[
[0.98446155, -0.030119859, 0.172998, 0.0],
[0.023979114, 0.9990097, 0.037477385, 0.0],
[-0.17395553, -0.032746706, 0.98420894, 0.0],
[0.024039675, -0.037087332, -0.22780673, 0.99999994]
])
As you can see, the cameraTransform.columns.2.z is positive despite the rear camera pointing towards True North, while cameraTransform.columns.3.z is correctly positive as the device is moving towards True North.
So here is my question:
Why is cameraTransform.columns.2.z positive when the rear camera is physically facing North?
Any clarity would be deeply appreciated. I've read the documentation and tested with different heading accuracies and AR session resets, but I keep running into this orientation mismatch.
Thanks in advance!
Discuss spatial computing on Apple platforms and how to design and build an entirely new universe of apps and games for Apple Vision Pro.
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Hi there,
I was looking to add a particle emitter to my augmented reality app I'm developing using RealityKit. I'm targeting iOS. I noticed in the documentation for the ParticleEmitterComponent that it looks like iOS 18.0+ is supported, but when I try to use the ParticleEmitterComponent in my code in XCode, I get an error that it isn't found. Furthermore, this StackOverflow post seems to indicate that particle systems are not available for iOS. Would it be possible to get clarification on this?
I want an AR character to be able to look at a position while still playing the characters animation.
So far, I managed to manually adjust a single bone rotation using
skeletalComponent.poses.default = Transform(
scale: baseTransform.scale,
rotation: lookAtRotation,
translation: baseTransform.translation
)
which I run at every rendering update, while a full body animation is running.
But of course, hardcoding single joints to point into a direction (in my case the head) does not look as nice, as if I were to run some inverse cinematic that includes, hips + neck + head joints.
I found some good IKRig code in Composing interactive 3D content with RealityKit and Reality Composer Pro.
But when I try to adjust rigs while animations are playing, the animations are usually winning over the IKRig changes to the mesh.
Apple, please provide access to face tracking blend shapes on vision os, just like you do on iOS.
You have the best eye and face tracking implementation on the market, please let us use it. There is a sizable audience who will buy the headset just for it.
I personally know multiple people who are not buying the headset simply because you locked those features out.
No raw camera access is needed, just abstracted blendshapes values. You will make the headset so much more useful if you do this simple thing.
I have been using ARKit to get hand tracking data on a continuous loop by implementing the AnchorUpdateSequence.
I want to try out the .predicted hand tracking, but it seems as though using ARKit session and HandTrackingProvider do not allow me to enable this feature?
Following up on my previous question here: https://developer.apple.com/forums/thread/774262
Having solved the clipping problem, I am now trying to overlay some content in front of the RealityView. However, it looks like any content with transparency does not render in front of the RealityView, while opaque views seem to work; placing content with transparency like glassBackgroundEffect() behind the RealityView in a ZStack causes the entire window to flicker.
Additionally, my SwiftUI attachment placed in front of the stereoscopic image plane are invisible if the user look at it straight at 90 degrees. However, if the user look at it from increasing angles from the sides, the attachment gradually turns visible again.
Are these behaviors expected? What is a recommended approach to overlay content in front of a RealityView? Thanks!
Seeing this magical sand table, the unfolding and folding effects are similar to spreading out cards, which is very interesting. But I don't know how to achieve it. I want to see if there are any ways to achieve this effect and give some ideas. May I ask if this effect can be achieved under the existing API
Topic:
Spatial Computing
SubTopic:
General
Hello! I’m familiar with the discussion on “Sending messages to the scene”, and I’ve successfully used that code.
However, I have several instances of the same model in my scene.
Is it possible to make only one specific model respond to a notification?
For example, can I pass something like RealityKit.NotificationTrigger.SourceEntity in userInfo or use another method to target just one instance?
Topic:
Spatial Computing
SubTopic:
Reality Composer Pro
Tags:
USDZ
Reality Composer
RealityKit
visionOS
I am developing an app which needs high-quality immersion on VisionOS. I found that when some messages pop up, the virtual object will get transparent so the immersion is broken. How could I disable such pop-up messages when the ImmersiveSpace is open
.
Hi, I have been using RealityRenderer to render scenes in MacOS as spatial videos and view it in Vision Pro and it is awesome. I understand that it uses PerspectiveCamera to render. I wanted to know what is the default FOV for this camera and how much can we push it? I want to ideally render a scene with 180 degrees of fov. Thanks
I am developing an visionos app. I load a .usdz file as a Reality Entity(such as a cabbage). And I want such an effect:
When I turn on a desk lamp in real world near the Entity, the surface of the Entity will correctly respond to the light in the real world.
I want an effect like this:
https://www.reddit.com/r/virtualreality/comments/1as01mm/shiny_disco_ball_reflecting_my_room/
I look up the api such as ImageBasedLightComponent andVirtualEnvironmentProbeComponent in RealityKit、EnvironmentLightEstimationProvider in ARKit,but I do not know how to code.
Besides, it will be better if the shadow will also respond to the light correctly.
Hello
When processing an ARPlaneAnchor geometry using its ARPlaneGeometry, the triangleIndices is an array of Int16. It's supposed to be an index buffer, which can only be uint16 or uint32 metal. What am I supposed to do with negative indices ? Negative indices are rare but do appear sometimes.
Thank you
Topic:
Spatial Computing
SubTopic:
ARKit
help me please i cant remove little messed up pixels and they are getting more and more please help me!!
2025 Macbook pro no protection screen actual screen
So it seems to be that there is a contradiction between how ARKit defines UIDeviceOrientation.landscapeRight, and the actual definition of UIDeviceOrientation.landscapeRight in the UIKit documentation.
In the ARKit documentation for ARCamera.transform, it says the following:
This transform creates a local coordinate space for the camera that is constant with respect to device orientation. In camera space, the x-axis points to the right when the device is in UIDeviceOrientation.landscapeRight orientation—that is, the x-axis always points along the long axis of the device, from the front-facing camera toward the Home button. The y-axis points upward (with respect to UIDeviceOrientation.landscapeRight orientation), and the z-axis points away from the device on the screen side.
Going through the same link, we see the definition of UIDeviceOrientation.landscapeRight given as:
The device is in landscape mode, with the device held upright and the front-facing camera on the right side.
There seems to be a conflict in the two definitions, that has already been asked and visualized in this StackOverflow thread
The resolution of that answer says that ARKit landscapeRight, unlike what is given in UIDeviceOrientation.landscapeRight, has home button on the right, as stated in the ARCamera.transform documentation.
It says that more details are given in this StackOverflow thread, but this thread talks about the discrepancy between the definitions of landscapeRight in UIDeviceOrientation and UIInterfaceOrientation, and not anything related to ARKit.
So I am wondering, why does ARKit definition of landscapeRight contradict with that of UIDeviceOrientation despite explicitly mentioning it? Is it just a mistake by Apple developers that hasn't been resolved even after so long?
We are building an AR experience for deployment on iphones. We are using Unity but it looks as if Reality Composer Pro has better features for spatial audio. I am not sure if Reality Composer Pro can only be used for Vision Pro or can it also be used for deployment on Iphone or ipad.
I am submitting a challenge to the Swift Student Challenge. I have created a RealityContent folder using Reality Composer Pro. How can I import this folder into the Swift Package Manager (.swiftpm) project hosted on Playground to ensure that it becomes a usable package?
Topic:
Spatial Computing
SubTopic:
Reality Composer Pro
Tags:
Swift Student Challenge
Swift Playground
RealityKit
Reality Composer Pro
I am trying the image tracking of ARKit on VisionPro, but there seems to be some problem when adding reference image.
Here is my code:
let images = ReferenceImage.loadReferenceImages(inGroupNamed: "photos")
print("Images: \(images)")
try await appState!.arkitSession.run([imageTracking])
It can successfully print those images, however sometimes it will print the error message like this:
ARImageTrackingRemoteService: Adding reference image <ARReferenceImage: 0x3032399e0 name="chair" physicalSize=(0.070, 0.093)> failed.
When this error message is printed, the corresponding image can not be tracked.
I do not understand why this will happen, because sometimes the image can be successfully added, but other time not, even for the same image. It makes my app not stable.
Besides, there are some other error messages, and I do not know whether it is related:
ARPredictorRemoteService <0x1042154a0>: Query queue is not running.
Execution of the command buffer was aborted due to an error during execution. Insufficient Permission (to submit GPU work from background) (00000006:kIOGPUCommandBufferCallbackErrorBackgroundExecutionNotPermitted)
It's all about notifications to trigger actions from RCP's new Timeline system. From Compose interactive 3D content in Reality Composer Pro I am actually starting to confuse why there was need to use Entity.applyTapForBehaviors in code to trigger content in Behaviors Component. Simply because in Behaviors Component, we have chosen OnTap to allow a "Tap Notification" to trigger our action (on a selected target object).
Then I guess by selecting OnCollision this trigger, I should write something like CollisionEvent.entityA.applyCollisionForBehaviors, which we don't have. And ofc the collision on my object won't trigger this action (because I only did things in RCP not in code).
Ignoring this post has pointed out we could use Behaviors Component's OnNotification to trigger something for now.
I found that I could still use OnTap trigger but actually put my code Entity.applyTapForBehaviors under my subscribed collision's begin event. That actually works better than OnCollision
So what is the design principles here? And how could I trigger a collision notification to let my Behaviors Component's OnCollision actually works?
I'm starting my journey in developing an immersive app for VisionOS. I've been making steady progress, but I've encountered a specific challenge that I haven't been able to resolve.
I created two ModelEntity objects — a sphere and a cube — and added a DragGesture to the cube. When I drag the cube over the sphere, the two collide correctly, and the collision is logged in the console. So far, everything works as expected.
However, when I try to anchor the cube to my hand, the collision stops working. It's as if the cube loses its ability to detect collisions once it's anchored.
Any guidance or clarification on this behavior would be greatly appreciated.
// ImmersiveView.swift
// estudos_vision
//
// Created by Lailan Rogerio Rodrigues Matos on 15/05/25.
//
import SwiftUI
import RealityKit
import RealityKitContent
struct ImmersiveView: View {
@Environment(AppModel.self) var appModel
@State private var session: SpatialTrackingSession?
@State private var box = ModelEntity()
@State private var subs: [EventSubscription] = []
@State private var ballEntity: Entity?
var body: some View {
RealityView { content in
// Load initial content from the RealityKit scene.
if let immersiveContentEntity = try? await Entity(named: "Immersive", in: realityKitContentBundle) {
content.add(immersiveContentEntity)
}
// Create and run a spatial tracking session.
let session = SpatialTrackingSession()
let configuration = SpatialTrackingSession.Configuration(tracking: [.hand])
_ = await session.run(configuration)
self.session = session
// Create a red box.
let boxMesh = MeshResource.generateBox(size: 0.2)
let material = SimpleMaterial(color: .red, isMetallic: false)
box = ModelEntity(mesh: boxMesh, materials: [material])
box.position.y += 0.15 // Position the box slightly above the origin.
// Configure the box for user interaction and physics.
box.components.set(InputTargetComponent(allowedInputTypes: .indirect)) // Make it interactive.
box.generateCollisionShapes(recursive: false) // Generate collision shapes for physics.
box.components.set(PhysicsBodyComponent( // Add physics behavior.
massProperties: .default,
material: .default,
mode: .kinematic // Use kinematic mode so it can be moved by user interaction.
))
box.components.set(GroundingShadowComponent(castsShadow: true)) // Add a shadow.
//content.add(box) //commented out to add to hand anchor
// Create a left hand anchor and add the box as a child.
let handAnchor = AnchorEntity(.hand(.left, location: .palm), trackingMode: .continuous)
handAnchor.addChild(box)
content.add(handAnchor) // Add the hand anchor to the scene.
// Create a sphere.
let ball = ModelEntity(mesh: .generateSphere(radius: 0.15))
ball.position = [0.0, 1.5, -1.0] // Initial position of the ball.
ball.generateCollisionShapes(recursive: false) // Add collision.
ball.name = "Sphere"
content.add(ball)
ballEntity = ball
// Subscribe to collision events between the box and other entities.
let event = content.subscribe(to: CollisionEvents.Began.self, on: box) { ce in
print("Collision between \(ce.entityA.name) and \(ce.entityB.name) occurred")
//ce.entityA.removeFromParent() // removes the colliding object
//ce.entityB.removeFromParent()
}
Task {
subs.append(event)
}
}
// Add a drag gesture to the box, allowing the user to move it.
.gesture(
DragGesture()
.targetedToEntity(box) // Target the drag gesture to the box.
.onChanged({ value in
// Update the position of the box based on the drag gesture.
box.position = value.convert(value.location3D, from: .local, to: box.parent!)
})
)
}
}
#Preview(immersionStyle: .full) {
ImmersiveView()
.environment(AppModel())
}
Topic:
Spatial Computing
SubTopic:
General
Hello, esteemed tech developer.
I am using the Apple Vision Pro to create an AR assist system about the da Vinci Surgical Robot in a medical surgical suite, and would like to capture eye movement data with tester uniformity. Although the Apple Vision Pro has a superb infrared sensor to monitor eye movement status, Apple does not seem to have open access officially. (I'm aware of many existing discussions about this, but I was still wondering if there might be an option, particularly for research labs.)Here's my FB number.FB16603687