Hi team, I'm looking for the RealityKit debugger in Xcode 26 beta 3. I'm running a RealityKit app on my iPad running iPadOS 26 b3, but the debugger option is not there in Xcode.

Hi all, I've encountered a potential issue with how the winding order of geometry is handled when their transformations involve negative scaling. I created a simple test asset, a single triangle, to demonstrate this. The triangle's vertices are defined in a counter-clockwise ("right-handed") winding order, and its transform has a negative scale on the X-axis. According to the OpenUSD specification, this negative determinant in the transformation matrix should effectively reverse the winding order of the geometry: However, any given gprim's local-to-world transformation can flip its effective orientation, when it contains an odd number of negative scales. This condition can be reliably detected using the (Jacobian) determinant of the local-to-world transform: if the determinant is less than zero, then the gprim's orientation has been flipped, and therefore one must apply the opposite handedness rule when computing its surface normals (or just flip the computed normals) for the purposes of hidden surface detection and lighting calculations. When I view the asset in tools like Blender or Preview on macOS, it behaves as expected. The triangle's effective orientation is flipped to CW. However, when the same asset is viewed in Reality Composer Pro or with QuickLook on iOS, its effective orientation remains CCW. In other words, the triangle faces the opposite direction. My questions for the community and Apple are: Is this behavior in RealityKit a known issue? If this is a known issue, is there official guidance for DCC tools on how to export USDZ assets to ensure they appear correctly in the Apple ecosystem? Any insights or recommendations would be greatly appreciated.

In the CanyonCrosser example project, some RealityKit systems are implemented as classes while others are structs. What’s the reason for using different types?

I am rewriting an unfinished SceneKit project as RealityKit (NonAR). As far as I can see, RealityKit is missing basic fog functionality? Fog was simple & easy to implement in SCeneKit (fogStartDistance / fogEndDistance / fogDensityExponent / fogColor). Are there any plans to implement something like this in RealityKit? Are there any simple workarounds?

I’m trying to use EXR lightmaps to overlay baked lighting on top of a base texture in the RCP Shader Graph. When I multiply an EXR image set to Image(float) with an 8-bit base texture, the output becomes Image(float). I can’t connect that to the BaseColor input on the UnlitSurface node, since it only accepts Color3f. I expected to be able to use a Convert node between the Multiply node and the BaseColor input, but when I do that, the result becomes black and white instead of the expected outcome: the EXR multiplied with the base texture using a baseline value of 1, where values below 1 in the EXR would darken the base texture and values above 1 would brighten it. Is there any documentation on how to properly overlay a 32-bit EXR lightmap in the RCP Shader Graph, or is the black-and-white output from the Convert node a bug?

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.

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.

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)

Hi, I'm trying to set the displayScale environment value for a RealityView, so it renders at 2x instead of 3x on the iPhone, but it seems to have no effect. .environment(\.displayScale, 2.0) Is this expected behavior, or a bug? The reason I want it to render at 2x and not at the default 3x is for game optimization and performance.

I want to fade objects in and out, and while setting an entity's OpacityComponent works, animating it doesn't seem to do anything. In the following code the second sphere should fade out, but it keeps its initial opacity. On the other hand, the animation that changes its transform works. What am I doing wrong? class ViewController: NSViewController { override func loadView() { let arView = ARView(frame: NSScreen.main!.frame) let anchor = AnchorEntity(.world(transform: matrix_identity_float4x4)) arView.scene.addAnchor(anchor) let sphere = ModelEntity(mesh: .generateSphere(radius: 0.5)) anchor.addChild(sphere) sphere.components.set(OpacityComponent(opacity: 0.1)) let sphere2 = ModelEntity(mesh: .generateSphere(radius: 0.5)) sphere2.position = .init(x: 0.2, y: 0, z: 0) anchor.addChild(sphere2) sphere2.components.set(OpacityComponent(opacity: 0.1)) sphere.playAnimation(try! AnimationResource.makeActionAnimation(for: FromToByAction(to: 0, timing: .linear), duration: 1, bindTarget: .opacity)) sphere.playAnimation(try! AnimationResource.makeActionAnimation(for: FromToByAction(to: Transform(translation: SIMD3(x: 0.1, y: 0, z: 0)), timing: .linear), duration: 1, bindTarget: .transform)) view = arView } }

I'm trying to convert my game from SceneKit to RealityKit. I noticed that even when the scene is static (nothing moves), RealityKit keeps using CPU. In SceneKit, CPU goes down to 0% with a static scene. With this simplest of games, RealityKit keeps using about 65% CPU: class ViewController: NSViewController { override func loadView() { view = ARView(frame: NSScreen.main!.frame) } } Is this expected or a bug? I created FB22125047.

In ARKit there is ARGeoAnchor, which lets you anchor content using latitude and longitude so objects stay fixed to a real-world location. Is there an equivalent feature in RealityKit? I want to place points in the world and make sure they don't move or drift after placement. If RealityKit doesn't support this directly, what is the recommended approach?

I'm trying to scale the physics of a scene without changing the apparent size to avoid the low-speed zeroing-out of motion that the physics simulation does. I found a technique for using separate simulation and physics roots in the docs, but it relies on ARView, which VisionOS doesn't have. This seems more elegant than scaling absolutely everything with shared root -- any chance I'm just failing in my searches to find the equivalent functionality?

Hi everybody, I have 2 separate animations run.usdz and walk.usdz animation files which are loaded perfectly in Reality Composer Pro and in the RealityKit application. I want to gradually increase the speed of my player by switching blending weight values from 0.0 (walking) to 1.0 (full speed running). let rabbit = await RabbitBuilder.loadWalkingRabbit() let runningRabbit = await RabbitBuilder.loadRunningRabbit() rabbit.scale = SIMD3(0.05, 0.05, 0.05) runningRabbit.scale = SIMD3(0.05, 0.05, 0.05) let walkAnimation = rabbit.availableAnimations let runAnimation = runningRabbit.availableAnimations RabbitWalker.walkAnim = walkAnimation.first! RabbitWalker.runAnim = runAnimation.first! guard let walk = RabbitWalker.walkAnim, let run = RabbitWalker.runAnim else { return } let blendTree = BlendTreeAnimation<JointTransforms>( BlendTreeBlendNode(sources: [ BlendTreeSourceNode(source: walk.definition, name: "walk", weight: .value(1 - weight)), BlendTreeSourceNode(source: run.definition, name: "run", weight: .value(weight)) ]), name: "rabbitLocomotion", repeatMode: .repeat, offset: TimeInterval(elapsed) ) // I have runtime error after executing this line: "Cannot add incompatible timeline type to blend tree." guard let resource = try? AnimationResource.generate(with: blendTree) else { return } entity.playAnimation(resource) static func loadWalkingRabbit() async -> Entity? { do { let scene = try await Entity(named: "Scene", in: realityKitEnvironmentBundle) guard let rabbit = await scene.findEntity(named: "RabbitWalk") else { return nil } await rabbit.removeFromParent() return rabbit } catch { return nil } } static func loadRunningRabbit() async -> Entity? { do { let scene = try await Entity(named: "Scene", in: realityKitEnvironmentBundle) guard let rabbit = await scene.findEntity(named: "RabbitRun") else { return nil } await rabbit.removeFromParent() return rabbit } catch { return nil } } But when I run this code I have this error; Cannot add incompatible timeline type to blend tree. By the way I have looked to developer's sample codes from here but I couldn't find any relevant BlendTreeAnimation sample which blends 2 animations. I would very happy if someone could direct me to a solution. Regards.

Developing a prototype Vision Pro app and would like to render a 3D scene made from Reality Composer Pro on an image anchor in a RealityView. But I have no luck so far to make it work and need some guidance to move on. I got the image file stored in the assets like below: And from below is the source codes: import SwiftUI import RealityKit import RealityKitContent struct AnchorView: View { @State var imageEntity: Entity = { let anchorEntity = AnchorEntity(.image(group: "AR Resources", name: "reanchor")) return anchorEntity }() var body: some View { RealityView { content in do { // Add the initial RealityKit content if let scene = try? await Entity(named: "Scene", in: realityKitContentBundle) { imageEntity.addChild(scene) content.add(imageEntity) } } catch { print("Error occurs when adding reality view content: \(error)") } } } }

Using Reality Composer Pro 2.0, I created a simple shader graph that displays a texture on an unlit surface: On visionOS 2 beta, I can successfully use ShaderGraphMaterial(named:from:in:) to load that shader graph material and assign it to a model entity. However, on visionOS 1.2 and earlier, either in Simulator or on the device, ShaderGraphMaterial(named:from:in:) fails and I see the following logged to the console: If, using Reality Composer Pro 1.0, I experimentally open the same project and delete and recreate exactly the same nodes above, then ShaderGraphMaterial(named:from:in:) works as expected on visionOS 1.2. Is it a known issue that Reality Composer 2 can't be used with visionOS 1? Is this intentional behavior? I've submitted feedback as FB14828873, including a sample project and repro steps. If possible, I would appreciate guidance from an Apple engineer, like "This is a known issue for [list of node types]" or "Reality Composer Pro 2 is not supported for visionOS 1 development, please refer to [documentation]" or "We recommend [workaround]." Thank you.

Hi there, I've discovered an issue with gesture handling in RealityKit when setting the camera’s fieldOfViewOrientation to horizontal. For instance, if I render a simple box at the center of the view with a collision shape that exactly matches its dimensions, the actual hit area behaves as if it's smaller than the box. Additionally, when attempting to drag the box away from the center, the hit area appears misaligned—offset slightly towards the center. Since the default fieldOfViewOrientation is vertical and everything works as expected in that mode, it seems that the gesture system might be assuming a vertical FOV. Given that the API allows setting it to horizontal, perhaps gestures should function correctly regardless of the orientation? Thank you!

My experience has been that ModelEntity(named:in:) can be used to load a USD file with a simple structure consisting of entities and model entities, and, critically, it will flatten the entity hierarchy down to a single ModelEntity, presumably reducing the number of draw calls. However, can anyone verify that the following is true? If ModelEntity(named:in:) is used to load a USD file from a RealityKit content bundle, it may fail when the USD file contains more complex data, such as shader graph material definitions, or perhaps for some other reason. I am not sure. AND the error that ModelEntity(named:in:) throws in this case is Cannot load RealityKitContent entity: Failed to find resource with name "<name>" in bundle which would literally suggest that the file does not exist, instead of what I assume the error actually is, which is "the file exists but its entity hierarchy could not be flattened to a single ModelEntity" ? Is that an accurate description of the known behavior of ModelEntity:named:in:)? I understand that I could use Entity(named:in:) instead, without the flattening feature. My question is really more about the seemingly misleading error message. Thank you for any clarification you can provide.

our app is live, and it appears that since the ios 18 update - the VideoMaterial renders pink / purple color instead of the video (picture attached). the audio is rendered properly. we found that it occurs on old devices: iPhone 11 & iPhone SE 2020. I've found this thread of Andy Jazz on stackoverflow: Steps to Reproduce: Create a plane for the video screen. Apply a VideoMaterial using AVPlayerItem. Anchor the model entity to an ARImageAnchor. Expected Outcome: The video should play as a material on the plane in RealityKit. Actual Outcome: On iOS 18, the plane appears pink, indicating the VideoMaterial isn’t applied. What I’ve Tried: -Verified the video URL is correct. -Checked that the AVPlayerItem and VideoMaterial are initialised correctly. -Ensured the AVPlayer is playing the video. I also tried different formats (mov / mp4 / m4v), and verifying that the video's status is readyToPlay. any suggestions?

I'm new here so I don't know what's this function belongs to which topic... Sorry about that! I watched the WWDC stream and I am really interested in this function, I'm wondering if this function could be used in my apps. I looked up the document but I find it only support visionOS(i'm not sure about that, but I saw the demo is base on the visionOS)