Goal: To render in an apple vision pro app, the solid-mechanics 3D simulation results coming form an FEA code. Starting point: I have surface vtks with deformations on each node. Each time step has a a mesh with the nodal coordinates. This is straighforward translatable to a usd MeshSequence. Unfortunately, the results cannot be simplified to a scaling o linear transformation as you would do with other game-oriented animations. Tools: Right now, I am using Xcode and reality composer pro (RCP) to build the scenes. Technical limitations: I am aware that RCP can do animations with BlendMesh and skeletons and that MeshSequence is not a problem. Progress: Coverting to the sequence of vtk meshes to a usd MeshSequence is straighforward. This animates correctly in Preview and Blender (see screenshot). I managed to convert from MeshSequence to multiple keys and BlendMesh. This also animates correctly in Blender and preview. Unfortunately, the BlendMesh of multiple blended meshes shows a zero animation time in RCP (see screenshot below) Also, see below usda file scheme for the animation. Of course I am not showing full vectors such as faceVertexCounts, faceVertexIndex, normals. Question: what is the right set up to create a BlendMesh animation that RCP will correctly import and animate, form a set of Meshes or multiple key shapes? Blender animation Time zero RCP "animations" #usda 1.0 ( defaultPrim = "BlendMeshRoot" doc = "Blender v4.5.3 LTS" endTimeCode = 48 framesPerSecond = 24 metersPerUnit = 1 startTimeCode = 0 timeCodesPerSecond = 24 upAxis = "Z" ) def Xform "BlendMeshRoot" ( customData = { dictionary Blender = { bool generated = 1 } } ) { def SkelRoot "Mesh" { custom string userProperties:blender:object_name = "Mesh" float3 xformOp:rotateXYZ = (89.99999, -0, 0) float3 xformOp:scale = (0.009999999, 0.01, 0.01) double3 xformOp:translate = (0, 0, 0) uniform token[] xformOpOrder = ["xformOp:translate", "xformOp:rotateXYZ", "xformOp:scale"] def Mesh "Mesh" ( active = true prepend apiSchemas = ["MaterialBindingAPI", "SkelBindingAPI"] ) { uniform bool doubleSided = 1 float3[] extent = [(25.091871, -34.121277, -13.298501), (299.94482, 245.10088, 202.35126)] int[] faceVertexCounts = [3, 3, ... int[] faceVertexIndices = [0, 10293, ... rel material:binding = </BlendMeshRoot/_materials/MeshSequence_Default> normal3f[] normals = [(-0.3632836, -0.9102419, -0.19870725), .... point3f[] points = [(244.41148, 155.42062, 70.454926),..... float3[] primvars:node_displacement = [(93.54703, 110.9341, 48.37992).... float3[] primvars:Normals = [(-0.0050530406, -0.9910114, -0.13368203),... int[] primvars:skel:jointIndices = [0, 0, 0, 0, 0 ... float[] primvars:skel:jointWeights = [1, 1, 1, 1, 1... uniform token[] skel:blendShapes = ["frame_0000", "frame_0001", "frame_0002", "frame_0003", "frame_0004", "frame_0005"] rel skel:blendShapeTargets = [ </BlendMeshRoot/Mesh/Mesh/frame_0000>, ....... </BlendMeshRoot/Mesh/Mesh/frame_0005>, ] prepend rel skel:skeleton = </BlendMeshRoot/Mesh/Skel> uniform token subdivisionScheme = "none" custom string userProperties:blender:data_name = "Mesh" custom float userProperties:originalTime float userProperties:originalTime.timeSamples = { 0: 0, } def BlendShape "frame_0000" { uniform vector3f[] offsets = [(0, 0, 0), (0, 0, 0),..... uniform int[] pointIndices = [0, 1, 2, ..... } ..... ..... #### BlendShape frame to 0005 ..... def Skeleton "Skel" ( prepend apiSchemas = ["SkelBindingAPI"] ) { uniform matrix4d[] bindTransforms = [( (1, 0, 0, 0), (0, 1, 0, 0), (0, 0, 1, 0), (0, 0, 0, 1) )] uniform token[] joints = ["joint1"] uniform matrix4d[] restTransforms = [( (1, 0, 0, 0), (0, 1, 0, 0), (0, 0, 1, 0), (0, 0, 0, 1) )] prepend rel skel:animationSource = </BlendMeshRoot/Mesh/Skel/Anim> def SkelAnimation "Anim" { uniform token[] blendShapes = ["frame_0000", "frame_0001", "frame_0002", "frame_0003", "frame_0004", "frame_0005"] float[] blendShapeWeights.timeSamples = { 0: [1, 0, 0, 0, 0, 0], 1: [0.9697085, 0.03029152, 0, 0, 0, 0], 2: [0.88787615, 0.11212383, 0, 0, 0, 0], ..... 46: [0, 0, 0, 0, 0.11212379, 0.8878762], 47: [0, 0, 0, 0, 0.030291557, 0.96970844], 48: [0, 0, 0, 0, 0, 1], } } } } def Scope "_materials" { def Material "MeshSequence_Default" { token outputs:surface.connect = </BlendMeshRoot/_materials/MeshSequence_Default/Principled_BSDF.outputs:surface> custom string userProperties:blender:data_name = "MeshSequence_Default" def Shader "Principled_BSDF" { uniform token info:id = "UsdPreviewSurface" float inputs:clearcoat = 0 float inputs:clearcoatRoughness = 0.03 color3f inputs:diffuseColor = (0.8, 0.4, 0.3) float inputs:ior = 1.5 float inputs:metallic = 0 float inputs:opacity = 1 float inputs:roughness = 0.5 float inputs:specular = 0.2 token outputs:surface } } } def Scope "AnimationClips" { custom rel animations = </BlendMeshRoot/Mesh/Skel/Anim> } def RealityKitComponent "AnimationLibrary" { custom rel animations = </BlendMeshRoot/Mesh/Skel/Anim> custom token info:id = "RealityKit.AnimationLibrary" custom double realitykit:approximateDuration = 2 custom double[] realitykit:clipDurations = [2] custom string[] realitykit:clipNames = ["Anim"] custom rel realitykit:clipTargets = </BlendMeshRoot/Mesh/Skel/Anim> custom double realitykit:frameRate = 24 custom bool realitykit:isAnimationLibrary = 1 } }

I'm developing an AR application for the iPad pro where the primary purpose is to overlay 3D design data on top of production parts. For alignment, we are using Vuforia (model targets) which work really well locally. The further the device is moved from the point of original alignment, we are seeing quite a bit of overlay error (drift?). My primary questions are: Are there any best practices to stabilize frame-to-frame tracking when using model targets? We are noticing drift as soon as the device starts moving (the drift appears to occur specifically in the direction the device is moving). After about 15 feet of movement, we are observing about 3-6" of overlay error These use cases can be over 100 feet long. In order to reset drift, we understand we'll need multiple alignment points (model targets) along the way. Is there a standard/best practice for this? Ex: have a new alignment point every x-feet? We are using plane anchors to set our alignment. Typically we attach it to the nearest plane; however, the anchor point can be very far away (the origin of the model, which often is not near where the virtual content is). Could this be the issue? The anchor is far from the plane that we attach it too. Would moving the anchor closer to the plane we attach it too improve stability? After a few steps, the plane we originally attach too will be out of FoV anyway. Thanks in advance!

Hi I have a monitoring app, that will take input video from uvc and process it using Metal, and eventually get a MTLTexture. The problem I'm facing is I have to convert MTLTexture to CGImage then call TextureResource.replace, which is super slow. Metal processing speed is same as input frame rate(50pfs), but MTLTexture -> CGImage -> TextureResource only got 7fps... Is there any way I can make it faster?

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?

Hello! I’m excited to see that Look to Scroll has been included in visionOS 26 Beta. I’m aiming to achieve a feature where the user’s gaze at a specific edge automatically scrolls to that position. However, I’ve experimented with ScrollView and haven’t been able to trigger this functionality. Could you advise if additional API modifiers are necessary? Thank you!

I am develop visionOS app. I am now very interested in Metal and Compositor Services, but I have not explored them in depth. I know that Metal has a higher degree of control freedom. I am wondering if using Compositor Services will have fewer functions than RealityKit in AR technology (such as scene reconstruction and understanding, hover effect, etc.).

Hello, I'm working with the new PortalComponent introduced in visionOS 2.0, and I've encountered some issues when transitioning entities between virtual and real-world spaces using crossingMode. Specifically: Lighting inconsistency: When CG content (ModelEntities with PhysicallyBasedMaterial) crosses the portal from virtual space into the real environment, the way light reflects on the objects changes noticeably. This causes a jarring visual effect, as the same material appears differently depending on the space it's in. Unnatural transition visuals: During the transition, the CG models often appear to "emerge from the wall," especially when crossing from virtual to real. This ruins the immersive illusion and feels visually unnatural. IBL adjustment attempts: I’ve tried adding an ImageBasedLightComponent to the world entity, and while it slightly improves the lighting consistency, the issue still remains to a noticeable degree. My goal is to create a seamless visual experience when CG entities cross between spaces, without sudden lighting shifts or immersion-breaking geometry reveals. Has anyone else experienced similar issues? Is there a recommended setup or workaround to better control lighting and visual fidelity when using crossingMode with portals in visionOS 2.0? Any guidance would be greatly appreciated. Thank you!

FB17999226

Hello, Thank you for your time. I have a question regarding visionOS app development. When placing a SwiftUI TextField inside RealityView.attachments, we found that focusing on the field does not bring up the virtual keyboard in front of the user. Instead, the keyboard appears around the user’s lower abdomen area. However, when placing the same TextField in a regular SwiftUI layer outside of RealityView, the keyboard appears in the correct position as expected. This suggests that the issue is specific to RealityView.attachments. We are currently exploring ways to have the virtual keyboard appear directly in front of the user when using TextField inside RealityViewAttachments. If there is any method to explicitly control the keyboard position or any known workarounds—including alternative UI approaches—we would greatly appreciate your guidance. Best regards, Sadao Tokuyama

Hi Apple Team, I’m working on a human portrait scanning application using PhotogrammetrySession, and I’ve been very impressed by the results. Thank you for building such a powerful and accessible photogrammetry solution into macOS! I do, however, have a question regarding mesh detail limitations on different Mac hardware configurations. When using PhotogrammetrySession.Request.Detail.custom and trying to set maximumPolygonCount = 1000000, I see the following log message: Clamped max poly count: 1000000 to device limit. 250000 is used. This is on an M1 Max with 32 GB RAM. I’m aware that PhotogrammetrySession.limits can report values like maximumInputImageDimension and maximumNumberOfInputImages, but I haven’t found documentation on how the maximumPolygonCount is determined, and what hardware specs influence it. Is it tied more to: • GPU performance (e.g. neural/graphics cores)? • CPU architecture? • Memory size or bandwidth? • Or is it fixed per SoC generation? I’d love to understand what kind of hardware upgrades (e.g. moving to M4 Pro or increasing RAM) could allow me to increase mesh complexity and generate more detailed models. Any insights would be greatly appreciated—and if this is covered in upcoming WWDC sessions or documentation, I’d be happy to tune in. Thanks in advance! KitCheng

prefetching logic for UICollectionView on VisionOS does not work. I have set up a Standalone test repo to demonstrate this issue. This repo is basically a visionOS version of Apple's guide project on implementation of prefetching logic. in repo you will see a simple ViewController that has UICollectionView, wrapped inside UIViewControllerRepresentable. on scroll, it should print 🕊️ prefetch start on console to demonstrate func collectionView(_ collectionView: UICollectionView, prefetchItemsAt indexPaths: [IndexPath]) is called. However it never happens on VisionOS devices. With the same code it behaves correctly on iOS devices

Hi Nathaniel, I spoke with you yesterday in the WWDC lab. Thanks for chatting with me! Is it possible to get a link to a doc that has some key metrics I'd find in a RealityKit trace so I know if that metric is exceeding limits and probably causing a problem? Right now, I just see numbers and have no idea if a metric is high or low :). This is specifically for a VisionOS app. Thanks, Bob

Hi! I'm currently trying to render another XR scene in front of a RealityKit one. Actually, I'm anchoring a plane to the head with a shader to display for left/right eye side-by-side images. By default, the camera has a near plane so I can directly draw at z=0. Is there a way to change the camera near plane? Or maybe there is a better solution to overlay image/texture for left/right eyes? Ideally, I would layer some kind of CompositorLayer on RealityKit, but that's sadly not possible from what I know. Thanks in advance and have a good day!

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!

Hi , I'm struggling with visionOS window management and need help with closing child windows programmatically. App Structure My app has a Main-Sub window hierarchy: AWindow (Home/Main) BWindow (Main feature window) CWindow (Tool window - child of BWindow) Navigation flow: AWindow → BWindow (switch, 1 window on screen) BWindow → CWindow (opens child, 2 windows on screen) I want BWindow and CWindow to be separate movable windows (not sheet/popover) so users can position them independently in space. The Problem CWindow doesn't close when BWindow closes by tapping the X button below the app (next to the window bar) User clicks X on BWindow → BWindow closes but CWindow remains CWindow becomes orphaned on screen Can close CWindow programmatically when switching BWindow back to AWindow App launch issue After closing both windows, CWindow is remembered as last window Reopening app shows only CWindow instead of BWindow User gets stuck in CWindow with no way back to BWindow I've Tried Environment dismissWindow in cleanup but its not working. // In BWindow.swift .onDisappear { if windowManager.isWindowOpen("cWindow") { dismissWindow(id: "cWindow") } } My App Structure Code Now // in MyNameApp.swift @main struct MyNameApp: App { var body: some Scene { WindowGroup(id: "aWindow") { AWindow() } WindowGroup(id: "bWindow") { BWindow() } WindowGroup(id: "cWindow") { CWindow() } } } // WindowStateManager.swift class WindowStateManager: ObservableObject { static let shared = WindowStateManager() @Published private var openWindows: Set<String> = [] @Published private var windowDependencies: [String: String] = [:] private init() {} func markWindowAsOpen(_ id: String) { markWindowAsOpen(id, parent: nil) } func markWindowAsClosed(_ id: String) { openWindows.remove(id) windowDependencies[id] = nil } func isWindowOpen(_ id: String) -> Bool { let isOpen = openWindows.contains(id) return isOpen } func markWindowAsOpen(_ id: String, parent: String? = nil) { openWindows.insert(id) if let parentId = parent { windowDependencies[id] = parentId } } func getParentWindow(of childId: String) -> String? { let parent = windowDependencies[childId] return parent } func getChildWindows(of parentId: String) -> [String] { let children = windowDependencies.compactMap { key, value in value == parentId ? key : nil } return children } func setNextWindowParent(_ parentId: String) { UserDefaults.standard.set(parentId, forKey: "nextWindowParent") } func getAndClearNextWindowParent() -> String? { let parent = UserDefaults.standard.string(forKey: "nextWindowParent") UserDefaults.standard.removeObject(forKey: "nextWindowParent") return parent } func forceCloseChildWindows(of parentId: String) { let children = getChildWindows(of: parentId) for child in children { markWindowAsClosed(child) NotificationCenter.default.post( name: Notification.Name("ForceCloseWindow"), object: nil, userInfo: ["windowId": child] ) forceCloseChildWindows(of: child) } } func hasMainWindowOpen() -> Bool { let mainWindows = ["main", "bWindow"] return mainWindows.contains { isWindowOpen($0) } } func cleanupOrphanWindows() { for (child, parent) in windowDependencies { if isWindowOpen(child) && !isWindowOpen(parent) { NotificationCenter.default.post( name: Notification.Name("ForceCloseWindow"), object: nil, userInfo: ["windowId": child] ) markWindowAsClosed(child) } } } } // BWindow.swift struct BWindow: View { @Environment(\.dismissWindow) private var dismissWindow @ObservedObject private var windowManager = WindowStateManager.shared var body: some View { VStack { Button("Open C Window") { windowManager.setNextWindowParent("bWindow") openWindow(id: "cWindow") } } .onAppear { windowManager.markWindowAsOpen("bWindow") } .onDisappear { windowManager.markWindowAsClosed("bWindow") windowManager.forceCloseChildWindows(of: "bWindow") } .onChange(of: scenePhase) { oldValue, newValue in if newValue == .background || newValue == .inactive { windowManager.forceCloseChildWindows(of: "bWindow") } } } } // CWindow.swift import SwiftUI struct cWindow: View { @ObservedObject private var windowManager = WindowStateManager.shared @State private var shouldClose = false var body: some View { // Content } .onDisappear { windowManager.markWindowAsClosed("cWindow") NotificationCenter.default.removeObserver( self, name: Notification.Name("ForceCloseWindow"), object: nil ) } .onChange(of: scenePhase) { oldValue, newValue in if newValue == .background { } } .onAppear { let parent = windowManager.getAndClearNextWindowParent() windowManager.markWindowAsOpen("cWindow", parent: parent) NotificationCenter.default.addObserver( forName: Notification.Name("ForceCloseWindow"), object: nil, queue: .main) { notification in if let windowId = notification.userInfo?["windowId"] as? String, windowId == "cWindow" { shouldClose = true } } } .onChange(of: shouldClose) { _, newValue in if newValue { dismissWindow() } } } The logs show everything executes correctly, but CWindow remains visible on screen. Questions Why doesn't dismissWindow(id:) work in cleanup scenarios? Is there a proper way to create a window relationships like parent-child relationships in visionOS? How can I ensure main windows open on app launch instead of tool windows? What's the recommended pattern for dependent windows in visionOS? Environment: Xcode 16.2, visionOS 2.0, SwiftUI

Hi 26 beta guys, I have apps using ARKit. In iPadOS 26 beta, ARKit stops working after switching to other apps. how to: Enable WindowMode in iPadOS 26 Launch my app and start ARSession Switch to another app (preference app, etc.) Switch back to my app AR stops updating camerafeed. I debug printed ARSessionDelegate, and found that after sessionWasInterrupted was called, sessionInterruptionEnded was never called. sessionInterruptionEnded is called if WindowMode disabled. Is this just a bug for 26 beta? I suspect there is similar problem with non-AR camera. Any idea?

I’m working with RealityView in visionOS and noticed that the content closure seems to run twice, causing content.add to be called twice automatically. This results in duplicate entities being added to the scene unless I manually check for duplicates. How can I fix that? Thanks.

The AR based app I am working on right now is experiencing an issue. Sometimes, the AR session fails with a call to my ARSessionObserver's session(_ session: ARSession, didFailWithError error: Error) with the following error: Error Domain=com.apple.arkit.error Code=102 "Required sensor failed." NSLocalizedFailureReason="A sensor failed to deliver the required input.," NSLocalizedRecoverySuggestion="Make sure that the application has the required privacy settings." The underlying error seems to point to the CoreMotion framework: Domain=CMErrorDomain Code=102 "(null) Some people seem to have experienced this issue and solved it by making sure that the Compass Calibration switch is ON in Settings > Privacy > Location Services > System Services. For context, the ARWorldTrackingConfiguration.worldAlignment is set to .gravity The thing is it is already ON when I experience this issue. I also noticed that this issue happens way more often on the iPhone 16e than in any other device. Has anyone had similar experiences? I am looking for a way to prevent this error from happening (ideally) or handling in a way that does not affect the user. Any help is appreciated

So I am exporting a .usdc file from blender that already has some morph animations. The animations play well in blender but when I export I cannot seem to play them in RealityKit or RCP. Entity.availableAnimations is an empty array. Not of the child objects in the entity hierarchy has an animation library component with it. Maybe I am exporting it wrong but I tried multiple combinations but doesn't seem to work. Here are my export settings in blender The original file I purchased is an FBX file that has the animation but when I try to directly get it in RealityConverter it doesn't seem to play animations.

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.