Problem Summary After upgrading to iOS 26.1 and 26.2, I'm experiencing a particle positioning bug in RealityKit where ParticleEmitterComponent particles render at an incorrect offset relative to their parent entity. This behavior does not occur on iOS 18.6.2 or earlier versions, suggesting a regression introduced in the newer OS builds. Environment Details Operating System: iOS 26.1 & iOS 26.2 Framework: RealityKit Xcode Version: 16.2 (16C5032a) Expected vs. Actual Behavior Expected: Particles should render at the position of the entity to which the ParticleEmitterComponent is attached, matching the behavior on iOS 18.6.2 and earlier. Actual: Particles appear away from their parent entity, creating a visual misalignment that breaks the intended AR experience. Steps to Reproduce Create or open an AR application with RealityKit that uses particle components Attach a ParticleEmitterComponent to an entity via a custom system Run the application on iOS 26.1 or iOS 26.2 Observe that particles render at an offset position away from the entity Minimal Code Example Here's the setup from my test case: Custom Component & System: struct SparkleComponent4: Component {} class SparkleSystem4: System { static let query = EntityQuery(where: .has(SparkleComponent4.self)) required init(scene: Scene) {} func update(context: SceneUpdateContext) { for entity in context.scene.performQuery(Self.query) { // Only add once if entity.components.has(ParticleEmitterComponent.self) { continue } var newEmitter = ParticleEmitterComponent() newEmitter.mainEmitter.color = .constant(.single(.red)) entity.components.set(newEmitter) } } } AR Setup: let material = SimpleMaterial(color: .gray, roughness: 0.15, isMetallic: true) let model = Entity() model.components.set(ModelComponent(mesh: boxMesh, materials: [material])) model.components.set(SparkleComponent4()) model.position = [0, 0.05, 0] model.name = "MyCube" let anchor = AnchorEntity(.plane(.horizontal, classification: .any, minimumBounds: [0.2, 0.2])) anchor.addChild(model) arView.scene.addAnchor(anchor) Questions for the Community Has anyone else encountered this particle positioning issue after updating to iOS 26.1/26.2? Are there known workarounds or configuration changes to ParticleEmitterComponent that restore correct positioning? Is this a confirmed bug, or could there be a change in coordinate system handling or transform inheritance that I'm missing? Additional Information I've already submitted this issue via Feedback Assistant(FB21346746)

Hello, I am in the process of implementing SharePlay support in my visionOS app. Everything runs fine when I test locally, but when my app is distributed via TestFlight, calling try await activity.activate() shows the SharePlay dialog as usual, but then when I start a new FaceTime call, my ImmersiveSpace gets dismissed. This is only happening when the app is distributed via TestFlight, when I run it locally the ImmersiveSpace stays active as expected. Looking at the console on my Mac I found this log: Invalid initial client settings class: UIApplicationSceneClientSettings; expected class: MRUISharedApplicationSceneClientSettings; bundle ID: com.apple.facetime; scene ID: com.apple.facetime:SFBSystemService-DDA8C751-C0C4-487E-AD85-59EF4E6C6050 Does anyone have an idea how I can fix this? It's driving me nuts and I wasted over a day looking for a workaround but so far been unsuccessful. Thanks!

Since updating to iOS 26.0 (and confirmed on 26.1), ARBodyTrackingConfiguration no longer detects a valid ARBodyAnchor on devices with LiDAR (e.g., iPhone 15 Pro, iPhone 17 Pro Max). This issue reproduces in custom projects and Apple’s official sample “Capturing Body Motion in 3D”. The AR session runs normally, but the delegate call: func session(_ session: ARSession, didUpdate anchors: [ARAnchor]) never yields an ARBodyAnchor with valid joint transforms. All joints return nil when calling: body.skeleton.modelTransform(for: jointName) resulting in 0 valid joints per frame. Environment • Device: iPhone 17 Pro Max (LiDAR) • iOS: 26.0 / 26.1 • Xcode: 16.0 (stable) • Framework: ARKit + RealityKit • Configuration used: config.worldAlignment = .gravityAndHeading config.isAutoFocusEnabled = true config.environmentTexturing = .none session.run(config) Also tested: with and without frameSemantics = .bodyDetection Expected Behavior ARBodyAnchor should be detected and body.skeleton should contain ~89 valid joints with continuous updates.

I have an arguably massive project and am not sure if the issue is with the assets or my approach in the code. the error says : Tool terminated due to error "SIGNAL 6:Abort trap:6" Basically I have around 15-20 assets (usda files built out of usdz files). In the code i am loading a scene with all the usda files and then have the functions to enable and disable a particular asset when needed. This was working as intended when i am using dummy assets(with less polygons, lesser textures) But when i placed the actual assets the error appears and persists. Do I have a bad approach of loading all the scenes at once? Previously i have used an approach which loads the scenes when needed and that involved some lag before rendering the assets. But my current approach(when using dummies) works like a dime rendering and hiding the assets in realtime with no lag. Kindly suggest any workarounds.

https://developer.apple.com/documentation/realitykit/videomaterial The documentation: "Video materials support transparency if the source video’s file format also supports transparency." I have a transparency video(Hand.mov, HEVC with alpha), I can show the video with transparency background correctly on Vision Pro Simulates, but on physic Device the video has a black background. I'm sure the video format is ok because I can see get the texture from video and display it on an UnlitMaterial. How can I show the transparency video correctly with the RealityKit/VideoMaterial?

After adding TextComponents to my Entities on visionOS, I have observed that visualBounds will ignore the TextComponents. Documentation states that it should render a rounded rectangle mesh. These mashes are visible on the device, but not visible in the debugger ("Capture Entity Hierarchy") and ignored by visualBounds. Am I missing something? static func makeDirection(_ direction: Direction) -> Entity { let text = Entity() text.name = direction.rawValue text.setScale(SIMD3(repeating: 5), relativeTo: nil) text.transform.rotation = direction.rotation text.components.set(direction.textComponent) return text } My workaround is to add a disabled ModelEntity and take its bounds 😬

What is the reason the hand-tracking joints have these axes? I'm trying to create a virtual hands model and that's a mess.

I'm trying to get video material to work on an imported 3D asset, and this asset is a USDC file. There's actually an example in this WWDC video from Apple. You can see it running on the flag in this airplane, but there are no examples of this, and there are no other examples on the internet. Does anybody know how to do this? You can look at 10:34 in this video. https://developer.apple.com/documentation/realitykit/videomaterial

I have a model that uses a video material as the surface shader and I need to also use a geometry modifier on the material. This seemed like it would be promising (adapted from https://developer.apple.com/wwdc21/10075 ~5m 50s). // Did the setup for the video and AVPlayer eventually leading me to let videoMaterial = VideoMaterial(avPlayer: avPlayer) // Assign the material to the entity entity.model!.materials = [videoMaterial] // The part shown in WWDC: Set up the library and geometry modifier before, so now try to map the new custom material to the video material entity.model!.materials = entity.model!.materials.map { baseMaterial in       try! CustomMaterial(from: baseMaterial, geometryModifier: geometryModifier)     } But, I get the following error Thread 1: Fatal error: 'try!' expression unexpectedly raised an error: RealityFoundation.CustomMaterialError.defaultSurfaceShaderForMaterialNotFound How can I apply a geometry modifier to a VideoMaterial? Or, if I can't do that, is there an easy way to route the AVPlayer video data into the baseColor of CustomMaterial?

I'm trying to understand how Apple handles dragging windows around in an immersive space. 3d Gestures seem to be only half of the solution in that they are great if you're standing still and want to move the window an exaggerated amount around the environment, but if you then start walking while dragging, the amplified gesture sends the entity flying off into the distance. It seems they quickly transition from one coordinate system to another depending on if the user is physically moving. If you drag a window and start walking the movement suddenly matches your speed. When you stop moving, you can push and pull the windows around again like a super hero. Am I missing something obvious in how to copy this behavior? Hello world, which uses the 3d gesture has the same problem. You can move the world around but if you walk with it, it flies off. Are they tracking the head movement and if it's moved more than a certain amount it uses that offset instead? Is there anything out of the box that can do this before I try and hack my own solution?

I have tried every combination of suggestions to get a skybox to appear. Using swiftUI, realityKit and iOS. Non immersive environment. Does anyone have code that works to display a skybox. When i use a do/catch loop i get environmentResource not found. I have checked the syntax, ensured the folder is referencing the target, used the same name for the folder as the file, the file is a .hdr (i assume this is supported), i have moved the file folder to the top level - no change.

I'm preparing my submission for the Swift Student Challenge, and I have a couple of questions regarding the development environment. Is it allowed to use Xcode to program my scene, or do I have to use Swift Playgrounds? Can I use iPadOS 18 for development? I noticed that Swift Playgrounds currently only supports up to iPadOS 17.5, but I would like to use RealityView, which is only available starting from iPadOS 18. I appreciate any clarification on this. Thanks in advance!

A ShaderGraphMaterial with an Occlusion Surface Output generated with RealityComposer 2 fails to load on iOS 18 and macOS 15 with the following error: RealityFoundation.ShaderGraphMaterial.LoadError.invalidTypeFound (https://developer.apple.com/documentation/realitykit/shadergraphmaterial/loaderror/invalidtypefound) This happens with both https://developer.apple.com/documentation/shadergraph/realitykit/occlusion-surface-(realitykit) and https://developer.apple.com/documentation/shadergraph/realitykit/shadow-receiving-occlusion-surface-(realitykit) RealityView { content in do { let bgEntity = ModelEntity(mesh: .generateCone(height: 0.5, radius: 0.1), materials: [SimpleMaterial(color: .red, isMetallic: true)]) bgEntity.position.z = -0.2 content.add(bgEntity) let occlusionMaterial = try await ShaderGraphMaterial(named: "/Root/OcclusionMaterial", from: "OcclusionMaterial") let testEntity = ModelEntity(mesh: .generateSphere(radius: 0.4), materials: [occlusionMaterial]) content.add(testEntity) content.cameraTarget = testEntity } catch { print("Shader Graph Load Error:") dump(error) } } .realityViewCameraControls(.orbit) .edgesIgnoringSafeArea(.all) Feedback ID: FB15081296

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.

Hi team, I believe I’ve found a registration issue between ARFrame.sceneDepth and ARFrame.capturedImage when using high-resolution frame capture on a 2022 iPad Pro (6th gen). When enabling high-resolution capture: if let highResFormat = ARWorldTrackingConfiguration.recommendedVideoFormatForHighResolutionFrameCapturing { config.videoFormat = highResFormat } … arView.session.captureHighResolutionFrame { ... } the depth map provided by ARFrame.sceneDepth no longer aligns correctly with the corresponding high-resolution capturedImage. This misalignment results in consistently over-estimated distance measurements in my app (which relies on mapping depth to 2D pixel coordinates). iPad Pro (6th gen): misalignment occurs only when capturing high-resolution frames. iPhone 16 Pro: depth is correctly registered for both standard and high-resolution captures. It appears the camera intrinsics, specifically the FOV, change between the “regular” resolution stream and the high-resolution capture on the iPad. My suspicion is that the depth data continues using the intrinsics of the lower resolution stream, resulting in an unregistered depth-to-RGB mapping. Once I have the iPad in hand again, I will confirm whether camera.intrinsics or FOV differ between the low-res and high-res frames. Is this a known issue with high-resolution frame capture on the 2022 iPad Pro? If not, I’m happy to provide some more thorough sample code. Thanks for your time!

Hi everyone! I am working on AR app and wanted to implement object occlusion because it removes drift pretty much from the object. This working great with RealityKit sample But I am unable to replicate such behaviour it with scenekit. Because scenekit does not offer object occlusion. Can we say scenekit is getting depricated, and we should re-write app in RealityKit (which is obviously a big task)?

I'm working on an application for viewing AMF models on macOS, using RealityKit. AMF supports several different ways to color models, including per-vertex color (where the color of a triangle is interpolated from vertex to vertex) as well as per-face color (where the color of the triangle is the same across the entire face). I'm trying to figure out how to support those color models using a RealityKit mesh. Apple's documentation (https://developer.apple.com/documentation/realitykit/modifying-realitykit-rendering-using-custom-materials) talks about per-vertex colors, but I haven't found a way to create a mesh that includes per-vertex colors, other than use a texture map (which might be the correct solution). Can someone give me some pointers?

Summary After updating to visionOS 26, we’ve encountered severe transparency rendering issues in RealityKit that did not exist in visionOS 2.6 and earlier. These regressions affect applications that dynamically control scene opacity (via OpacityComponent). Our app renders ultra-realistic apartment environments in real time, where users can walk or teleport inside 3D spaces. When the user moves above a speed threshold, we apply a global transparency effect to prevent physical collisions with real-world objects. Everything worked perfectly in visionOS 2.6 — the problems appeared only after upgrading to 26. Scene Setup Overview The environment consists of multiple USDZ models (e.g., architecture, rooms, furniture). We manage LODs manually for performance (e.g., walls and floors always visible in full-res, while rooms swap between low/high-res versions based on user position and field of view). Transparency is achieved using OpacityComponent, applied dynamically when the user moves. Some meshes (e.g., portals to skyboxes, glass windows) use alpha materials We also use OcclusionMaterials to prevent things to be seen through walls when scene is transparent Observed Behavior by Scenario (I can share a video showing the results of each scenario if needed.) Scenario 1 — Severe Flickering (Root Opacity) Setup: OpacityComponent applied to the root entity NO ModelSortGroupComponent used Symptoms: Strong flickering when transparency is active Triangles within the same mesh render at inconsistent opacity levels Appears as if per-triangle alpha sorting is broken Workaround: Moving the OpacityComponent from the root to each individual USDZ entity removes the per-triangle flicker Pros: No conflicts with portals or alpha materials Scenario 2 — Partially Stable, But Alpha Conflicts Setup: OpacityComponent applied per USDZ entity ModelSortGroupComponent(planarUIAlwaysBehind) applied to portal meshes Other entities have NO ModelSortGroupComponent Symptoms: Frequent alpha blending conflicts: Transparent surfaces behind other transparent surfaces flicker or disappear Example: Wine glasses behind glass doors — sometimes neither is rendered, or only one Even opaque meshes behind glass flicker due to depth buffer confusion Alpha materials sometimes render portals or the real world behind them, ignoring other geometry entirely Analysis: Appears related to internal changes in alpha sorting or depth pre-pass behavior introduced in visionOS 26 Pros: Most stable setup so far Cons: Still unreliable when OpacityComponent is active Scenario 3 — Layer Separation Attempt (Regression) Setup: Same as Scenario 2, but: Entities with alpha materials moved to separate USDZs Explicit ModelSortGroupComponent order set (alpha surfaces rendered last) Symptoms: Transparent surfaces behind other transparent surfaces flicker or disappear Depth is completely broken when there's a large transparent surface Alpha materials sometimes render portals or the real world behind them, ignoring other geometry entirely Workaround Attempt: Re-ordering and further separating models did not solve it Pros: None — this setup makes transparency unusable Conclusion There appears to be a regression in RealityKit’s handling of transparency and sorting in visionOS 26, particularly when: OpacityComponent is applied dynamically, and Scenes rely on multiple overlapping transparent materials. These issues did not exist prior to 26, and the same project (no code changes) behaves correctly on previous versions. Request We’d appreciate any insight or confirmation from Apple engineers regarding: Whether alpha sorting or opacity blending behavior changed in visionOS 26 If there are new recommended practices for combining OpacityComponent with transparent materials If a bug report already exists for this regression Thanks in advance!

Is there any support pr plans for support for for raytraced reflections in RealityKit on the Vision Pro M5? I cannot find any documentation regarding this topic.

Hello, Question re: iOS RealityView postProcess. I've got a working postProcess kernel and I'd like to add some depth-based effects to it. Theoretically I should be able to just do: encoder.setTexture(context.sourceDepthTexture, index: 1) and then in the kernel: texture2d<float, access::read> depthIn [[texture(1)]] ... outTexture.write(depthIn.read(gid), gid); And I consistently see all black rendered to the view. The postProcess shader works, so that's not the issue. It just seems to not be receiving actual depth information. (If I set a breakpoint at the encoder setTexture step, I can see preview the color texture of the scene, but the context's depthTexture looks like all NaN / blank.) I've looked at all the WWDC samples, but they include ARView for all the depth sample code, which has a different set of configuration options than RealityView. So far I haven't seen anywhere to explicitly tell RealityView "include the depth information". So I'm not sure if I'm missing something there. It appears that there is indeed a depth texture being passed, but it looks blank. Is there a working example somewhere that we can reference?