Hi, I'm rewriting my game from SceneKit to RealityKit, and I'm having trouble implementing the following scenario: I tap on the iPhone screen to select an Entity that I want to drag. If an Entity was tapped, it should then be possible to drag it left, right, etc. SceneKit solution: func CGPointToSCNVector3(_ view: SCNView, depth: Float, point: CGPoint) -> SCNVector3 { let projectedOrigin = view.projectPoint(SCNVector3Make(0, 0, Float(depth))) let locationWithz = SCNVector3Make(Float(point.x), Float(point.y), Float(projectedOrigin.z)) return view.unprojectPoint(locationWithz) } and then I was calling: SCNView().hitTest(location, options: [SCNHitTestOption.firstFoundOnly:true]) the code was called inside of the UIPanGestureRecognizer in my UIViewController. Could I reuse that code or should I go with the SwiftUI approach - something like that: var body: some View { RealityView { .... } .gesture(TapGesture().onEnded { }) ? I already have this code: @State private var location: CGPoint? .onTapGesture { location in self.location = location } I'm trying to identify the entity that was tapped within the RealityView like that: RealityView { content in let box: ModelEntity = createBox() // for now there is only one box, however there will be many boxes content.add(box) let anchor = AnchorEntity(world: [0, 0, 0]) content.add(anchor) _ = content.subscribe(to: SceneEvents.Update.self) { event in //TODO: find tapped entity, so that it could be dragged inside of the DragGesture() } Any help would be appreciated. I also noticed that if I create a TapGesture like that: TapGesture(count: 1) .targetedToAnyEntity() and add it to my view using .gesture() then it is not triggered.

My app is running Compute Shaders that use non-uniform thread groups. When I run the app in the debugger with a simulator target the app crashes on encoder.dispatchThreads and the error message is: Dispatch Threads with Non-Uniform Threadgroup Size is not supported on this device. Previously the log output states that: Metal Shader Validation is unsupported for Simulator. However: When I stop the debugger and just run the app in the simulator without the debugger attached, the app just runs fine and does not crash. The SwiftUI Preview that also triggers the Compute Shader when preparing data also just runs fine without a crash. I can run and debug on a real device no problem - I just don't have all sizes available. Is there anything I need to check in my lldb/simulator configuration? It obviously does work, just the debugger cannot really deal with it? Any input would be nice as this really slows my down as I have to be extremely careful when debugging on the simulator.

Hello! I'm developing a GPU (shader) language, where I aim to target multiple backends with a common frontend. I wanted to avoid having to round trip through Metal, and go straight to IR just like I have with SPIRV, in order to have a fast and efficient compilation process. I've been looking for a reference page where I can read about Metals IR, and as far as I'm aware, it exists, but I can't seem to find it anywhere. Furthermore, if such a reference is available, is there also a toolkit where I can run validation on the output IR, and perhaps even run optimizations, much like spv-tools for SPIRV? Any help would be appreciated! Thanks, Gustav

Hey, i have created a game in unity with the apple core and apple gamekit plugins present. I setup 5 leaderboards on the app store connect. I made a unity build and did the whole testflight build loop to test everything. When i open my gamecenter panel via the button i see my leaderboards but they show as MISSING TITLE which is weird because i have for sure set them up correctly they have a leaderboard reference name and leaderboard id as well. When debugging i can see that when i call my submit score function it gets submitted with no error but then i also dont see the score appear anywhere . Keep in mind the leaderboards are not live and are being tested on testflight first

In my project, I have several nodes (SCNNode) with some levels of detail (SCNLevelOfDetail) and everything works correctly, but when I add animation using morphing (SCNMorpher), the animation works correctly but without the levels of detail. Note: the entire scene is created in Autodesk 3D Studio Max and then exported in (.ASE) format. The goal is to make animations using morphing that have some levels of detail. Does anyone know if SCNMorpher supports geometry with some levels of detail? I appreciate any information about this case. Thanks everyone!!! Part of the code I use to load geometries (SCNGeometry) with some levels of detail (SCNLevelOfDetail) using morphing (SCNMorpher). node.morpher = [SCNMorpher new]; SCNGeometry *geometry = [self geometryWithMesh:mesh]; NSMutableArray <SCNLevelOfDetail*> *mutLevelOfDetail = [NSMutableArray arrayWithCapacity:self.mutLevelsOfDetail.count]; for (int i = 0; i < self.mutLevelsOfDetail.count; i++) { ASCGeomObject *geomObject = self.mutLevelsOfDetail[i]; SCNGeometry *geometry = [self geometryWithMesh:geomObject.mesh.mutMeshAnimation[i]]; [mutLevelOfDetail addObject:[SCNLevelOfDetail levelOfDetailWithGeometry:geometry worldSpaceDistance:geomObject.worldSpaceDistance]]; } geometry.levelsOfDetail = mutLevelOfDetail; node.morpher.targets = [node.morpher.targets arrayByAddingObject:geometry];

Now the examples of metal-cpp are target on desktop and using AppKit which is not supported on iOS. Is there any tips for developing with metal-cpp on mobile device?

We are trying to implement saving and fetching data to and from iCloud, but it have some problems. MacOS: 15.3 Here is what I do: Enable Game Center and iCloud capbility in Signing & Capabilities, pick iCloud Documents, create and select a Container. Sample code: void SaveDataToCloud( const void* buffer, unsigned int datasize, const char* name ) { if(!GKLocalPlayer.localPlayer.authenticated) return; NSData* data = [ NSData dataWithBytes:databuffer length:datasize]; NSString* filename = [ NSString stringWithUTF8String:name ]; [[GKLocalPlayer localPlayer] saveGameData:data withName:filename completionHandler:^(GKSavedGame * _Nullable savedGame, NSError * _Nullable){ if (error != nil) { NSLog( @"SaveDataToCloud error:%@", [ error localizedDescription ] ); } }]; } void FetchCloudSavedGameData() { if ( !GKLocalPlayer.localPlayer.authenticated ) return; [ [ GKLocalPlayer localPlayer ] fetchSavedGamesWithCompletionHandler:^(NSArray<GKSavedGame *> * _Nullable savedGames, NSError * _Nullable error) { if ( error == nil ) { for ( GKSavedGame *item in savedGames ) { [ item loadDataWithCompletionHandler:^(NSData * _Nullable data, NSError * _Nullable error) { if ( error == nil ) { //handle data } else { NSLog( @"FetchCloudSavedGameData failed to load iCloud file: %@, error:%@", item.name, [ error localizedDescription ] ); } } ]; } } else { NSLog( @"FetchCloudSavedGameData error:%@", [ error localizedDescription ] ); } } ]; } Both saveGameData and fetchSavedGamesWithCompletionHandler are not reporting any error, when debugging, saveGameData completionHandler got a nil error, and can get a valid "savedGame", but when try to rebot the game and use "fetchSavedGamesWithCompletionHandler" to fetch data, we got nothing, no error reported, and the savedGames got a 0 length. From this page https://developer.apple.com/forums/thread/718541?answerId=825596022#825596022 we try to wait 30sec after authenticated , then try fetchSavedGamesWithCompletionHandler, still got the same error. Checked: Game Center and iCloud are enabled and login with the same account. iCloud have enough space to save. So what's wrong with it.

Hi, What's the best way to handle drastic changes in scene charateristics with the new MTLFXTemporalDenoisedScaler? Let's say a visible object of the scene radically changes its material properties. I can modify the albedo and roughness textures consequently. But I suspect the history will be corrupted. Blending visual information between the new frame and the previous ones might be a nonsense. I guess the problem should be the same when objects appear or disappear instantly. Is the upsacler manage these events for us (by lowering blending), or should we use the reactive or the denoise strength mask or something like that to handle them?

Imagine a native macOS app that acts as a "launcher" for a Java game.** For example, the "launcher" app might use the Swift Process API or a similar method to run the java command line tool (lets assume the user has installed Java themselves) to run the game. I have seen How to Enable Game Mode. If the native launcher app's Info.plist has the following keys set: LSApplicationCategoryType set to public.app-category.games LSSupportsGameMode set to true (for macOS 26+) GCSupportsGameMode set to true The launcher itself can cause Game Mode to activate if the launcher is fullscreened. However, if the launcher opens a Java process that opens a window, then the Java window is fullscreened, Game Mode doesn't seem to activate. In this case activating Game Mode for the launcher itself is unnecessary, but you'd expect Game Mode to activate when the actual game in the Java window is fullscreened. Is there a way to get Game Mode to activate in the latter case? ** The concrete case I'm thinking of is a third-party Minecraft Java Edition launcher, but the issue can also be demonstrated in a sample project (FB13786152). It seems like the official Minecraft launcher is able to do this, though it's not clear how. (Is its bundle identifier hardcoded in the OS to allow for this? Changing a sample app's bundle identifier to be the same as the official Minecraft launcher gets the behavior I want, but obviously this is not a practical solution.)

Hi, The metal-cpp distribution appears to only contain headers for Foundation and Quartzcore. The LearnMetalCPP download [1] provides a ZIP with an metal-cpp-extensions directory containing AppKit.hpp and MetalKit.hpp headers. First question: Are these headers distributed anywhere else more publicly? Without these headers only the renderer can be fully written in C++ as far as I can tell, i.e. no complete C++ NSApplication. Second question: Will these headers, if needed, be maintained (e.g. updated and/or extended) by Apple along side metal-cpp? [1] https://developer.apple.com/metal/cpp/ Thank you and regards.

Hey all — I’ve been building out my first set of Game Center Achievements for a game I’m working on, and I’ve run into something odd with the image quality. The specs say to upload icons at 512x512 or 1024x1024@2x. I’ve been uploading 1024x1024 PNGs (without explicitly naming them “@2x” since there’s only one upload slot), assuming that Game Center would just handle the scaling automatically — kind of like how a lot of things are getting more streamlined across platforms lately. But in testing, the icons are showing up a bit blurry, especially in the Game Center interface. It’s not horrible, but it’s definitely softer than I expected — more like low-res than Retina. All my test devices (outside the Simulator) are running iOS 26, so I’m also wondering if this might be a beta-related display bug? Has anyone else run into this? Curious if I’m missing a best practice here, or if I really do need to ensure I’m uploading it with the @2x suffix, or maybe something else entirely? Thanks!

Hi I have attempted to find a fix for my issue via documentation online and one phone support ( not code level support ) call to no end. I could continue to try various things but would like to see if someone else has encountered this issue and a fix for it. Background: My Game app is live on App Store and has 1 classic leaderboard . I am now getting ready to submit an update to the app and it also entails adding a new recurring leaderboard. I added the leaderboard in App Store. I however have NOT uploaded my new build yet. I have also not added my leaderboards ( currently live and not live ) to any set. When I try to submit scores using GKLeaderboard.submitScore(_:context:player:leaderboardIDs:completionHandler:) to the new non-live leaderboard it works ( gives me no error ) When I try to load the scores from the new non-live leaderboard GKLeaderboard.loadLeaderboards(IDs:completionHandler:) loadEntries(for:timeScope:range:completionHandler:) it fails. Error: "leaderboardID not found" I could try ( and will ) uploading the new build to AppStore connect and associating the new leaderboard to it before testing again. try associating each leaderboard to a set Is there anything else that I should be aware of ? Thanks in advance

So I'm trying to use SpriteKit to make the background of my game. The walls have alpha 1.0, and the safe area alpha 0 and fully transparent. (e.g. a big black square with a smaller transparent square in the middle of it). Yet sprite kit always assume the entire image is either fully opaque or fully transparent. That defies its purpose isn't it? Is there a way to make this work?

Hi all im having a variety of issues with gamekit matchmaking. On the simulator the matchmaking ui pops up and I can click Quick Match, then immediately "Failed to find Players" this is the same with a real Apple ID and a sandbox account. If I use real devices the app at least discovers a match, but then the match none of the delegate methods for the match ever get called and the logs are filled with socket not connected and various errors. My questions are: Should match making via quick match work in the simulator, I have seen tutorial videos etc of this working, but I can't seem to get it to work. How do people debug issues with GameCenter / Gamekit to find out why its not able to connect? Many thanks in advance

Hello, Could someone post code that shows how to implement GCVirtualController to move a box around the screen? I've been poking around with GCVirtualController and gotten as far as having the D-pad and A B buttons appear on the display. But how do I make it do anything?

I play this game called Sonic Forces: Speed Battle that's available in the app store and I completed a quest outside of the app on this site called TapResearch for some rewards as I've done before and has worked, but after this one time I can no longer enter back into the game without crashing immediately. I tried deleting and reinstalling but nothing. I even tried signing into a different account but that didn't work either. So then I tried to make a new game center account to try and see if it works, and it did, though all my progress has been restarted. Does anyone know how to fix this?

TL;DR: RealityKit and Reality Composer Pro aren't forward or backward compatible with each other, and the resulting error message is terse and unhelpful. (FB14828873) So far, I've been sticking with Xcode 16.4 for development and only using Xcode 26.0 beta experimentally. Yesterday, I used xcode-select to switch to Xcode 26.0 beta 3 to test it, but I forgot to switch back. Consequently, this morning I unintentionally used the future Reality Composer Pro (the version included with Xcode 26) to make a small change to a USD file. Now I realize that if I'm unlucky, it's possible Reality Composer Pro may have silently introduced a small change into the USD file that may make RealityKit fail to read the file on iOS 18 and visionOS 2, which in the past has resulted in hours of debugging to track down the source of the failure, often a single line in the USD file that RealityKit can't communicate to me other than with the error "the operation couldn't be completed". As an analogy, this situation is as if, during regular development (not involving Reality Composer Pro), Xcode didn't warn you about specific API version conflicts, but instead failed with a generic error message, without highlighting the line in your Swift file that was the source of the error.

I want to compare the colors of two model entities (spheres). How can i do it? The method i'm currently trying to apply is as follows case let .color(controlColor) = controlMaterial.baseColor, controlColor == .green { // Flip target sphere colour if let targetMaterial = targetsphere.model?.materials.first as? SimpleMaterial, case let .color(targetColor) = targetMaterial.baseColor, targetColor == .blue { targetsphere.model?.materials = [SimpleMaterial(color: .green, isMetallic: false)] // Change to |1⟩ } else { targetsphere.model?.materials = [SimpleMaterial(color: .blue, isMetallic: false)] // Change to |0⟩ } } This method (baseColor) was deprecated in swift 15.0 changes to 'color' but i cannot compare the value color to each other.👾

Hello, I am experiencing an issue with a character animation using RealityKit. I have a file created in Blender that contains the rigged Character, a sword, and a shield. The sword and the shield have bones connected to the character's hands so they can follow the character's animation. When I run the animation in Blender and preview the exported USDZ file on Mac, I can see the sword and shield attached to the hands and the animation is fine. But when I add the USDZ model in RealityKit and play the animation, only the character is animating, the sword and the shield are not moving at all. This is the code I use to animate the character: private func loadAnimations() { let unifiedAnimations = children[0].availableAnimations.first!.definition let animationResource = try! AnimationResource.generate(with: unifiedAnimations) self.children[0].playAnimation( animationResource.repeat() ) } Here is a link with a Demo Xcode project, the Blender file, and a video: https://www.dropbox.com/scl/fi/ypq2iwxc5f9dwzjggsvin/AppleTest.zip?rlkey=wiag3rg44urhjdh2wal8cdx2u&st=vbpf7x11&dl=0 STEPS TO REPRODUCE I have created a demo project that displays the character on a horizontal surface, and the animation starts playing. Run the App. The ARView will be set up, and a yellow square will appear in the middle of the screen. When a horizontal surface is detected the yellow Square will change indicating that the surface is found. Tap on the screen to load the USDZ model and position it in the yellow square's position. The Animation will start playing and you can see that the character is animating, but the sword and shield remain still. Thanks

Hello I am trying to get thread group memory access in fragment shader. In essence, I would like to have all the fragments in a tile to bitwiseOR some value. My idea was to use simd_or across the SIMD group, then make each SIMD group thread 0 to atomic or the value into thread group memory. Finally very first thread of the tile would be tasked with writing the value down to texture with write access. Now, I can allocate the thread group memory argument to the fragment function all right. MTLRenderEncoder has setThreadgroupMemoryLength call, which I am using the following way [renderEncoder setThreagroupMemoryLength: 16 offset: 0 atIndex:0] Unfortunately, all I am getting is the following error (runtime assertion) -[MTLDebugRenderCommandEncoder setThreadgroupMemoryLength:offset:atIndex:]:3487: failed assertion Set Threadgroup Memory Length Validation offset + length(16) must be <= threadgroupMemoryLength(0).` What I am doing wrong? How I can get thread group memory in the fragment shader? I know I could use tile shading and compute function but the problem is that here I really like to use fragment stuff. Will be grateful for help.