Hello,
A lot of the RealityKit APIs (Ex. LowLevelMesh, LowLevelTexture, etc.) are marked with MainActor so they needed to be accessed on the main thread.
This creates issues when we need to perform expensive GPU related operations since now we need to perform those on the main thread. This results in bottlenecks and hangs in our application. We would like to use a multi-threaded approach to solve these problems which is difficult to do here. We are constantly streaming data whether the app is just appearing or the user is interacting with our application so we need to be able to perform these operations on a separate thread.
Any advice on how to achieve this using RealityKit?
Thank you.
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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the timeline editor feels often unfinished. Setting the time cursor to a different time is often not reflected in the preview.
You either have to click a clip or wait.
sometimes the cursor even disappears, eg. when switching tabs to shadergraph
Not being able to select and move multiple clips is missing.
There is also no snapping to clips or time cursor as found in other tools.
And then there is the timeline compile bug
https://developer.apple.com/forums/thread/810868
The timeline as it is, is a good start but it definitely needs some more love to be on par with other commercial tools like Unity or After Effects.
Topic:
Spatial Computing
SubTopic:
Reality Composer Pro
We're trying to switch from using main camera access on Arkit to screen-capture with passthrough however we're facing some issues and it seems a bit complicated to debug.
We have set up a broadcast Extension, set up some logs on the sample Handler but we get nothing in the console nor that the recording starts, we set up the picker as well and we can see our extension in the control center as one of the choices but clicking start, results in it stopping in less than one second after.
The only message that is rather contradictory we see in the console.app is the following
[INFO] -[RPRecordingManager getSystemBroadcastExtensionInfo:]_block_invoke:1333 Extension has passthrough license
and just right after
[INFO] -[RPRecordingManager getSystemBroadcastExtensionInfo:]_block_invoke:1336 Extension does not have passthrough license
Is there any interest in this forum for those developing for the spatial web and safari. I can't seem to find any posts that are relevant here.
I'm developing a VisionOS app with bouncing ball physics and struggling to achieve natural bouncing behavior using RealityKit's physics system. Despite following Apple's recommended parameters, the ball loses significant energy on each bounce and doesn't behave like a real basketball, tennis ball, or football would.
With identical physics parameters (restitution = 1.0), RealityKit shows significant energy loss. I've had to implement a custom physics system to compensate, but I want to use native RealityKit physics. It's impossible to make it work by applying custom impulses.
Ball Physics Setup (Following Apple Forum Recommendations)
// From PhysicsManager.swift
private func createBallEntityRealityKit() -> Entity {
let ballRadius: Float = 0.05
let ballEntity = Entity()
ballEntity.name = "bouncingBall"
// Mesh and material
let mesh = MeshResource.generateSphere(radius: ballRadius)
var material = PhysicallyBasedMaterial()
material.baseColor = .init(tint: .cyan)
material.roughness = .float(0.3)
material.metallic = .float(0.8)
ballEntity.components.set(ModelComponent(mesh: mesh, materials: [material]))
// Physics setup from Apple Developer Forums
let physics = PhysicsBodyComponent(
massProperties: .init(mass: 0.624), // Seems too heavy for 5cm ball
material: PhysicsMaterialResource.generate(
staticFriction: 0.8,
dynamicFriction: 0.6,
restitution: 1.0 // Perfect elasticity, yet still loses energy
),
mode: .dynamic
)
ballEntity.components.set(physics)
ballEntity.components.set(PhysicsMotionComponent())
// Collision setup
let collisionShape = ShapeResource.generateSphere(radius: ballRadius)
ballEntity.components.set(CollisionComponent(shapes: [collisionShape]))
return ballEntity
}
Ground Plane Physics
// From GroundPlaneView.swift
let groundPhysics = PhysicsBodyComponent(
massProperties: .init(mass: 1000),
material: PhysicsMaterialResource.generate(
staticFriction: 0.7,
dynamicFriction: 0.6,
restitution: 1.0 // Perfect bounce
),
mode: .static
)
entity.components.set(groundPhysics)
Wall Physics
// From WalledBoxManager.swift
let wallPhysics = PhysicsBodyComponent(
massProperties: .init(mass: 1000),
material: PhysicsMaterialResource.generate(
staticFriction: 0.7,
dynamicFriction: 0.6,
restitution: 0.85 // Slightly less than ground
),
mode: .static
)
wall.components.set(wallPhysics)
Collision Detection
// From GroundPlaneView.swift
content.subscribe(to: CollisionEvents.Began.self) { event in
guard physicsMode == .realityKit else { return }
let currentTime = Date().timeIntervalSince1970
guard currentTime - lastCollisionTime > 0.1 else { return }
if event.entityA.name == "bouncingBall" || event.entityB.name == "bouncingBall" {
let normal = event.collision.normal
// Distinguish between wall and ground collisions
if abs(normal.y) < 0.3 { // Wall bounce
print("Wall collision detected")
} else if normal.y > 0.7 { // Ground bounce
print("Ground collision detected")
}
lastCollisionTime = currentTime
}
}
Issues Observed
Energy Loss: Despite restitution = 1.0 (perfect elasticity), the ball loses ~20-30% energy per bounce
Wall Sliding: Ball tends to slide down walls instead of bouncing naturally
No Damping Control: Comments mention damping values but they don't seem to affect the physics
Change in mass also doesn't do much.
Custom Physics System (Workaround)
I've implemented a custom physics system that manually calculates velocities and applies more realistic restitution values:
// From BouncingBallComponent.swift
struct BouncingBallComponent: Component {
var velocity: SIMD3<Float> = .zero
var angularVelocity: SIMD3<Float> = .zero
var bounceState: BounceState = .idle
var lastBounceTime: TimeInterval = 0
var bounceCount: Int = 0
var peakHeight: Float = 0
var totalFallDistance: Float = 0
enum BounceState {
case idle
case falling
case justBounced
case bouncing
case settled
}
}
Is this energy loss expected behavior in RealityKit, even with perfect restitution (1.0)?
Are there additional physics parameters (damping, solver iterations, etc.) that could improve bounce behavior?
Would switching to Unity be necessary for more realistic ball physics, or am I missing something in RealityKit?
Even in the last video here: https://stepinto.vision/example-code/collisions-physics-physics-material/ bounce of the ball is very unnatural - stops after 3-4 bounces. I apply custom impulses, but then if I have walls around the ball, it's almost impossible to make it look natural. I also saw this post https://developer.apple.com/forums/thread/759422 and ball is still not bouncing naturally.
Hello,
Let me ask you a question about Apple Immersive Video.
https://www.apple.com/newsroom/2024/07/new-apple-immersive-video-series-and-films-premiere-on-vision-pro/
I am currently considering implementing a feature to play Apple Immersive Video as a background scene in the app I developed, using 3DCG-created content converted into Apple Immersive Video format.
First, I would like to know if it is possible to integrate Apple Immersive Video into an app.
Could you provide information about the required software and the integration process for incorporating Apple Immersive Video into an app?
It would be great if you could also share any helpful website resources.
I am considering creating Apple Immersive Video content and would like to know about the necessary equipment and software for producing both live-action footage and 3DCG animation videos.
As I mentioned earlier, I’m planning to play Apple Immersive Video as a background in the app. In doing so, I would also like to place some 3D models as RealityKit entities and spatial audio elements.
I’m also planning to develop the visionOS app as a Full Space Mixed experience. Is it possible to have an immersive viewing experience with Apple Immersive Video in Full Space Mixed mode? Does Apple Immersive Video support Full Space Mixed?
I’ve asked several questions, and that’s all for now. Thank you in advance!
Using the example code posted here:
https://developer.apple.com/documentation/visionOS/tracking-images-in-3d-space
I can register multiple ReferenceImage s with a ImageTrackingProvider, but only one updates at a time - to have realtime updating, I can only have one ImageAnchor in my field of view at a time.
Is it possible to track multiple imageAnchors at the same time in the same field of view? As in having several ImageAnchor's tracked and entities updated to the transforms of the anchor in the same frame/moment from the Apple Vision Pro?
Topic:
Spatial Computing
SubTopic:
ARKit
Hi!
I attempted to run a sample project for detecting human pose in photos, which can be found here:
https://developer.apple.com/documentation/vision/detecting-human-body-poses-in-3d-with-vision
The project works perfectly when run on my Macbook Pro M1, but it fails on Apple Vision Pro. After selecting the photo an endless loading screen is presented and the following output is produced in the console:
Failed to initialize 2D Detection Algorithm.
Failed to initialize 2D Pose Estimation Algorithm.
Failed to initialize algorithm modules
Network path is nil: (null)
Failed to initialize 2D Detection Algorithm.
Failed to initialize 2D Pose Estimation Algorithm.
Failed to initialize algorithm modules
Unable to perform the request: Error Domain=com.apple.Vision Code=9 "Async status object reported as failed but without an error" UserInfo={NSLocalizedDescription=Async status object reported as failed but without an error}.
de-activating session 70138 after timeout
It seems that VNDetectHumanBodyPose3DRequest is failing on Vision Pro for some reason. Are there any additional requirements for running Vision framework on VisionOS, that I might be missing?
Hi guys,
I noticed that Apple created a really engaging visual effect for browsing spatial videos in the app. The video appears embedded in glass panel with glowing edges and even shows a parallax effect as you move around. When I tried to display the stereo video using RealityView, however, the video entity always floats above the panel.
May I ask how does VisionOS implement this effect? Is there any approach to achieve this effect or example code I can use in my own code.
Thanks!
Error:
RoomCaptureSession.CaptureError.exceedSceneSizeLimit
Apple Documentation Explanation:
An error that indicates when the scene size grows past the framework’s limitations.
Issue:
This error is popping up in my iPhone 14 Pro (128 GB) after a few roomplan scans are done. This error shows up even if the room size is small. It occurs immediately after I start the RoomCaptureSession after the relocalisation of previous AR session (in world tracking configuration). I am having trouble understanding exactly why this error shows and how to debug/solve it.
Does anyone have any idea on how to approach to this issue?
When assigning a ManipulationComponent to an Entity SceneEvents.WillRemoveEntity will be called for that Entity.
Expected Behavior: the Entity is not (even if temporarily) removed from the Scene and no SceneEvents will be triggered as a result of assigning a ManipulationComponent.
FB20872220
Game Controller Input Limitations in visionOS Volumetric Windows
Hello Apple Developer Community,
I'm developing a game for visionOS and have encountered significant limitations with game controller input when using volumetric windows (WindowGroup with .volumetric style). I'd appreciate clarification on whether this is expected behavior and any guidance on best practices.
🧩 Issue Summary
When using a DualSense controller with a volumetric window in visionOS, only a subset of controller inputs are available to the app. The remaining inputs appear to be reserved by the system for UI navigation.
✅ Working Inputs (Volumetric Window)
D-Pad (all directions)
L3 (left thumbstick button click)
R3 (right thumbstick button click)
Menu button
Options button
❌ Not Working Inputs (Volumetric Window)
Left thumbstick analog movement (used for UI scrolling instead)
Right thumbstick analog movement (used for UI scrolling instead)
Face buttons (Cross, Circle, Square, Triangle / A, B, X, Y)
Shoulder buttons (L1, R1)
Triggers (L2, R2)
Key observation: When moving the left thumbstick in a volumetric window, the window's UI scrolls vertically instead of sending input to my app's GameController handlers. Similarly, face buttons seem to be reserved for system UI interactions.
⚙️ Implementation Details
I'm using the standard GameController framework:
Connect to controller via GCController.controllers()
Access extendedGamepad profile
Set up valueChangedHandler and pressedChangedHandler for all inputs
Handlers confirmed registered via logging
Working inputs (D-Pad, L3, R3) trigger immediately and consistently
Non-working inputs (thumbsticks, face buttons) never trigger
🧠 Critical Finding: ImmersiveSpace Works Perfectly
When testing the exact same code in an ImmersiveSpace (.mixed immersion style), all controller inputs work perfectly:
✅ Both thumbsticks provide full analog input
✅ All face buttons trigger their handlers
✅ All shoulder buttons and triggers work correctly
✅ 100% success rate with no intermittent issues
This suggests the issue isn't with my code, but rather how visionOS handles controller input differently between Volumetric Windows and ImmersiveSpace.
🧪 Test Environment
I created a minimal test project (Controller-Playground) to isolate the issue:
A simple ControllerTester class that registers all GameController handlers
A visual UI showing real-time input state
No game logic, RealityKit physics, or other complexity
Results
In volumetric window: Only D-Pad, L3, R3, Menu, Options work
In ImmersiveSpace: All inputs work perfectly
This confirms the limitation exists at the visionOS platform level, not in app code.
🧰 Attempted Workarounds
I tried the following without success:
Setting GCSupportsControllerUserInteraction = false in Info.plist
Setting UIRequiresFullScreen = true
Changing window styles (.plain, .volumetric)
Polling vs. handler-based input approaches
Various threading models (MainActor, separate thread)
Result: The only way to enable full controller support is to switch to ImmersiveSpace.
❓ Questions for Apple
Is this input reservation behavior in volumetric windows intended and documented?
Are game controllers expected to have limited functionality in volumetric windows while full functionality is reserved for ImmersiveSpace?
Is there a way to request full controller input access in a volumetric window, or is ImmersiveSpace the only option for complete controller support?
Where can I find official documentation about controller input differences between window types?
Are there any APIs or configuration options to disable system controller shortcuts in volumetric windows?
🎯 Impact
This limitation has a significant effect on game design and architecture:
Volumetric windows offer a multitasking-friendly, less immersive experience
ImmersiveSpace provides full controller support but may be more immersive than some games require
Games that only need basic D-Pad and button input can work fine in volumetric windows
Games requiring analog sticks or face buttons must currently use ImmersiveSpace
It would be very helpful if Apple could clarify or reference existing documentation regarding controller input handling in different visionOS window types. If such documentation doesn't exist yet, it might be valuable to include this information in future developer guides or best-practice documents.
🕹 Current Workaround
For now, I'm using:
D-Pad for character movement (digital 8-direction)
R3 (right stick click) as a substitute for the "X" button
This setup allows the game to function within a volumetric window, though full controller support still requires ImmersiveSpace.
📄 Request
If this is expected behavior, I may have simply missed the relevant documentation — could you please point me to any existing resources that explain this design?
If there isn't one yet, it would be great if future visionOS documentation could:
Clearly outline controller input behavior across window types
Provide guidance on when to use Volumetric Windows vs. ImmersiveSpace for games
Consider adding an API option to request full controller access when appropriate
If this is not expected behavior, I'm happy to file a detailed bug report with sample code.
💻 System Information
visionOS: Latest Simulator
Xcode: Latest version
Controller: Sony DualSense
Framework: GameController (standard extendedGamepad profile)
Test project: Minimal reproducible example available
Thank you for any clarification or guidance you can provide. This information would be valuable for many developers working on visionOS games.
Hi I know it's possible to play equirectangular VR180 video either SBS or MV-HEVC. And for fisheye video, the only way I know is to convert it into an AIVU for playback.
Is there any way to directly play fisheye video using AVPlayer? Thanks a lot!
We are working on a world scale AR app that leverages the device location and heading to place objects in the streets, so that they are correctly and stably anchored to certain locations.
Since the geo-tracking imagery is only available in certain cities and areas, we are trying to figure out how to fallback when geo-tracking is not available as the device move away, to still retain good AR camera accuracy. We might need to come up with some algorithm using the device GPS, to line up the ARCamera with our objects.
Question: Does geo-tracking always provide greater than or equal to the accuracy of world tracking, for a GPS outdoor AR experience?
If so, we can simply use the ARGeoTrackingConfiguration for the entire time, and rely on the ARView keeping itself aligned. Otherwise, we need to switch between it and ARWorldTrackingConfiguration when geo-tracking is not available and/or its accuracy is low, then roll our own algorithm to keep the camera aligned.
Thanks.
My VisionOS App (Travel Immersive) has two interface windows: a main 2D interface window and a 3D Earth window. If the user first closes the main interface window and then the Earth window, clicking the app icon again will only launch the Earth window while failing to display the main interface window. However, if the user closes the Earth window first and then the main interface window, the app restarts normally.
Below is the code of
import SwiftUI
@main
struct Travel_ImmersiveApp: App {
@StateObject private var appModel = AppModel()
var body: some Scene {
WindowGroup(id: "MainWindow") {
ContentView()
.environmentObject(appModel)
.onDisappear {
appModel.closeEarthWindow = true
}
}
.windowStyle(.automatic)
.defaultSize(width: 1280, height: 825)
WindowGroup(id: "Earth") {
if !appModel.closeEarthWindow {
Globe3DView()
.environmentObject(appModel)
.onDisappear {
appModel.isGlobeWindowOpen = false
}
} else {
EmptyView() // 关闭时渲染空视图
}
}
.windowStyle(.volumetric)
.defaultSize(width: 0.8, height: 0.8, depth: 0.8, in: .meters)
ImmersiveSpace(id: "ImmersiveView") {
ImmersiveView()
.environmentObject(appModel)
}
}
}
I am wondering, is it possible to somehow configure a 3D object to respond to the gaze of a person, like change colors of some parts of the 3D-Model where a person is looking, i.e. where a person's gaze lands on the surface of the 3D-model ?
For example, if there is a 3D model of a Cool Dragon 🐉 in the physical space of a person, when seen through with the mixed reality view, of a VisionPro. Now, it would be really cool to change only the color, or make some specific parts of the dragon skin shimmer, but only in the areas where a person is looking. Is this possible ? Is it do-able with eye-tracking of VisionPro ?
Any advice would be appreciated. 🤝 🤓 I am new to iOS and VisionOS development.
Topic:
Spatial Computing
SubTopic:
General
I want to make a model with added bones move by dragging it with gestures,This is a model exported using Blender,
What I understand is using IKComponent, but I don't know how to use it specifically
When I get close to an Entity in RealityKit wearing VisionPro. The Entity will become transparent so I can distinguish it is rendering by VisionPro instead of an object in reality world. How can I make it not transparent when I get close to the Entity?
The Section struct only publicly makes the center property available, but this is a SIMD3 that doesn't seem to line up with the rest of the model. All other objects have a 4x4 transform matrix that accurately gives each position and rotation.
When inspecting a Section in the debugger, many more properties are visible such as polygon and transform. Why are these not visible? The transform in particular seems necessary to make any sort of use of the Sections.
Is it possible to create a button in my app that will turn on the spatial personas for the user? Currently the only way I know of turning on spatial personas is by selecting the cube icon in the FaceTime window which is quite clunky for people unfamiliar with the Vision Pro's UI. Any help would be appreciated.