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Game Center challenges and activities issues for released game
We have a released game in the App Store with Game Center Challenges. The challenges were working well in testing of the final version before the Game Center challenges went live. After release the activity that should take the player to the challenge in game results in this printout and we do not get informed by GKGameActivityListener of the activity happening in our code as we did before the Game Center challenges went live. “Invalid game activity definition. Failed to kick activity notification to GameKit. Error: Error Domain=GKErrorDomain Code=17 "(null)"” Also, Game Center reports that the are no challenges in GKChallengeDefinition.all even though there are ongoing challenges. The leaderboard results do get reported to Game Center though and show up as challenge entries in the Games app. At the moment we are trying to figure out if this is a problem on our end or a Game Center server issue.
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macOS 26 Games app – Achievement description shows incorrect text before unlocking
Hello, I found an issue with the Games app on macOS 26 (Tahoe) when viewing achievements: In App Store Connect, each achievement has different values set for the pre-earned description and the post-earned description. When testing with GameKit directly (GKAchievementDescription), both values are returned correctly. However, in the macOS Games app, the post-earned description is shown even before the achievement is earned. This seems to be a display issue specific to the Games app on macOS. Could you confirm if this is a known bug in the Games app, or if there is a reason why pre-earned descriptions are not being shown? Thank you.
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ReplayKit Issue on iOS 26
When previewing the recording of gameplay the buttons to exit or save are unclickable behind the top bar clock and Wi-Fi/5G status bar. Which means that you have to quit the game in order to continue. Tested on multiple devices. Does anyone have a solution to this? At the moment we have disabled it altogether for iOS 26 users.
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Custom EntityAction - different behaviour VisionOS 2.6 vs 26
I implemented an EntityAction to change the baseColor tint - and had it working on VisionOS 2.x. import RealityKit import UIKit typealias Float4 = SIMD4<Float> extension UIColor { var float4: Float4 { if cgColor.numberOfComponents == 4, let c = cgColor.components { Float4(Float(c[0]), Float(c[1]), Float(c[2]), Float(c[3])) } else { Float4() } } } struct ColourAction: EntityAction { // MARK: - PUBLIC PROPERTIES let startColour: Float4 let targetColour: Float4 // MARK: - PUBLIC COMPUTED PROPERTIES var animatedValueType: (any AnimatableData.Type)? { Float4.self } // MARK: - INITIATION init(startColour: UIColor, targetColour: UIColor) { self.startColour = startColour.float4 self.targetColour = targetColour.float4 } // MARK: - PUBLIC STATIC FUNCTIONS @MainActor static func registerEntityAction() { ColourAction.subscribe(to: .updated) { event in guard let animationState = event.animationState else { return } let interpolatedColour = event.action.startColour.mixedWith(event.action.targetColour, by: Float(animationState.normalizedTime)) animationState.storeAnimatedValue(interpolatedColour) } } } extension Entity { // MARK: - PUBLIC FUNCTIONS func changeColourTo(_ targetColour: UIColor, duration: Double) { guard let modelComponent = components[ModelComponent.self], let material = modelComponent.materials.first as? PhysicallyBasedMaterial else { return } let colourAction = ColourAction(startColour: material.baseColor.tint, targetColour: targetColour) if let colourAnimation = try? AnimationResource.makeActionAnimation(for: colourAction, duration: duration, bindTarget: .material(0).baseColorTint) { playAnimation(colourAnimation) } } } This doesn't work in VisionOS 26. My current fix is to directly set the material base colour - but this feels like the wrong approach: @MainActor static func registerEntityAction() { ColourAction.subscribe(to: .updated) { event in guard let animationState = event.animationState, let entity = event.targetEntity, let modelComponent = entity.components[ModelComponent.self], var material = modelComponent.materials.first as? PhysicallyBasedMaterial else { return } let interpolatedColour = event.action.startColour.mixedWith(event.action.targetColour, by: Float(animationState.normalizedTime)) material.baseColor.tint = UIColor(interpolatedColour) entity.components[ModelComponent.self]?.materials[0] = material animationState.storeAnimatedValue(interpolatedColour) } } So before I raise this as a bug, was I doing anything wrong in the former version and got lucky? Is there a better approach?
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RealityKit - How to change camera target in response of a touch event?
Hello, I’m porting my UIKit/SceneKit app to SwiftUI/RealityKit and I’m wondering how to change the camera target programmatically. I created a simple scene in Reality Composer Pro with two spheres. My goal is straightforward: when the user taps a sphere, the camera should look at it as the main target. Following Apple’s videos, I implemented the .gesture modifier and it is printing the tapped sphere correctly, but updating my targetEntity state doesn’t change anything, so the camera won't update its target. Is there a way to access the scene content at that level? Or what else should I do? Here’s my current code implementation: Thanks!
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iPhone limited to 60hz frame rate
Just wondering if anyone knows what it will take to hit greater than 60hz when targeting iPhone. If I set the preferredFramesPerSecond of an MTKView to 120, it works on the iPad, but on iPhone it never goes over 60hz, even with a simple hello triangle sample app... is this a limitation of targeting iPhone?
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iOS 26 Games app: Wired Switch Pro controllers (and GameSir X5 Lite) not working correctly
Hi, Since iOS 26 introduced the new Games app, I’ve noticed a problem when using a Nintendo Switch Pro Controller in wired USB-C mode, and also with third-party controllers that emulate it (like the GameSir X5 Lite). In the Games app interface, only the L/R buttons respond, but the D-Pad and analog sticks don’t work at all. Once inside actual games, the controller works fine — the issue only affects the Games app UI. What I’ve tested so far: Xbox / PlayStation controllers → work fine in both wired and Bluetooth, including inside the Games app. Switch Pro Controller (Bluetooth) → works fine, including in the Games app. Switch Pro Controller (wired) → same issue as the X5 Lite, D-Pad and sticks don’t work in the Games app. This makes it hard to use the new Games app launcher with these controllers, even though they work perfectly once a game is launched. My question: is this an iOS bug (Apple needs to add proper support for wired Switch Pro controllers in the Games app), or something that Nintendo / GameSir would need to address? Thanks in advance to anyone who can confirm this or provide more info.
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Unity GameKit Plugin w/ Matchmaking Queue is not working
TLDR; I can't get QueueName to work with matchmaking a turn-based match in Unity using matchmaking rules. Long version: I'm using the apple unity plugin found here: https://github.com/apple/unityplugins/blob/main/plug-ins/Apple.GameKit/Apple.GameKit_Unity/Assets/Apple.GameKit/Documentation~/Apple.GameKit.md I have created a Queue, RuleSet and a simple Rule to match players by following these docs tightly: https://developer.apple.com/documentation/gamekit/finding-players-using-matchmaking-rules. Here is the single rule I have that drives matchmaking: { "data" : { "type" : "gameCenterMatchmakingRules", "id" : "[hiddden-rule-id]", "attributes" : { "referenceName" : "ComplimentaryFactionPreference", "description" : "default desc", "type" : "MATCH", "expression" : "requests[0].properties.preference != requests[1].properties.preference", "weight" : null }, "links" : { "self" : "https://api.appstoreconnect.apple.com/v1/gameCenterMatchmakingRules/[hidden-rule-id]" } }, "links" : { "self" : "https://api.appstoreconnect.apple.com/v1/gameCenterMatchmakingRules" } } which belongs to a rule set which belongs to a queue. I have verified these are setup and linked via the App Store Connect API. Additionally, when I tested queue-based matchmaking without a queue established, I got an error in Unity. Now, with this, I do not. However there is a problem when I attempt to use the queue for matchmaking. I have the basic C# function here: public override void StartSearch(NSMutableDictionary<NSString, NSObject> properties) { if (searching) return; base.StartSearch(properties); //Establish matchmaking requests _matchRequest = GKMatchRequest.Init(); _matchRequest.QueueName = _PreferencesToQueue(GetSerializedPreferences()); _matchRequest.Properties = properties; _matchRequest.MaxPlayers = PLAYERS_COUNT; _matchRequest.MinPlayers = PLAYERS_COUNT; _matchTask = GKTurnBasedMatch.Find(_matchRequest); } The _PreferencesToQueue(GetSerializedPreferences()); returns the exact name of the queue I added my ruleset to. After this function is called, I poll the task generated from the .Find(...) function. Every time I run this function, a new match is created almost instantly. No two players are ever added to the same match. Further, I'm running two built game instances, one on a mac and another on an ipad and when I simultaneously test, I am unable to join games this way. Can someone help me debug why I cannot seem to match make when using a queue based approach?
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How to use Unity Apple GameKit Plugin For Rule-based matchmaking?
Hello, **I'm Using ** Unity 6 LTS Unity Apple GameKit + Core plugins Turn-based matchmaking interface w/ 2 players max App Store Connect API for rule-based matchmaking I have already enabled game center in app store connect (I think) authenticated players and matched via friend request I am stuck Using queues to match players automatically I'm working on a rule-based matchmaking system which aims to place two players against each other into a GKTurnBasedMatch. I have a simple Unity Project that correctly authenticates a user and proceeds to send a matchmaking request. The matchmaking script utilizes the Unity plugins' GKTurnBasedMatchmakerViewController.Request(...) request function with a GKMatchRequest.Init() request configured with a QueueName equal to the App Store Connect API Queue I created. The queue I created is also linked to a ruleset with a very basic rule that checks if the properties contains a key called 'preference' that contains a string value for what side the player wants to play for this match. If during the matchmaking, the preferences between players are different, then the match is made and both players should join the match; each player gets to play the side they have chosen. I have my rule expression designed to just check if the preferences are not equal: requests[0].properties.faction_preference != requests[1].properties.faction_preference When I launch the game with two physical iPads and begin the matchmaking request, each player is immediately presented with two options: Invite a friend, or Start game The Problem: Inviting a friend works to get two players into a game, but queue seems to not matter, and clicking start game will just put the current player into its own match (no one joins). The Question: How do I get queue based matchmaking to work in Unity for a Turn-based match with only two players who are able to select the enemy side they want to play dictated by a rule that compares enemy play-side preferences? Resources I've used: Apple Unity GameKit Plugin: https://github.com/apple/unityplugins Matchmaking: https://developer.apple.com/documentation/gamekit/matchmaking-rules Multiplayer rulesets: https://developer.apple.com/documentation/gamekit/finding-players-using-matchmaking-rules
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GameKit not working as expected in iOS 26.
I just upgraded my macOS, Xcode and Simulator all to the newest beta version 26. Then I found two issues when building my app with Xcode 26 and running it on simulator 26. The game center access point no longer shows up in the app. This is how it's configured in the past. And it still works on simulator 18.4 func authenticatePlayer() { GKAccessPoint.shared.location = .topTrailing self.localPlayer.authenticateHandler = { viewController, error in if let viewController = viewController { // can present Game Center login screen } else if self.localPlayer.isAuthenticated { // game can be started } else { // user didn't log in, continue the game without game center } } } After game ended, the leaderboard won't load. This is how it's implemented in the past. It's still working in simulator 18.4 struct GameCenterView: UIViewControllerRepresentable { @Environment(\.presentationMode) var presentationMode ... func makeUIViewController(context: Context) -> GKGameCenterViewController { let viewController = GKGameCenterViewController( leaderboardID: getLeaderBoardID(with: leaderBoardGameMode), playerScope: .global, timeScope: .allTime ) viewController.gameCenterDelegate = context.coordinator return viewController } func updateUIViewController(_ uiViewController: GKGameCenterViewController, context: Context) {} func makeCoordinator() -> Coordinator { Coordinator(self) } class Coordinator: NSObject, GKGameCenterControllerDelegate { let parent: GameCenterView init(_ parent: GameCenterView) { self.parent = parent } func gameCenterViewControllerDidFinish(_ gameCenterViewController: GKGameCenterViewController) { parent.presentationMode.wrappedValue.dismiss() } } }
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Showing a MTLTexture on an Entity in RealityKit
Is there any standard way of efficiently showing a MTLTexture on a RealityKit Entity? I can't find anything proper on how to , for example, generate a LowLevelTexture out of a MTLTexture. Closest match was this two year old thread. In the old SceneKit app, we would just do guard let material = someNode.geometry?.materials.first else { return } material.diffuse.contents = mtlTexture Our flow is as follows (for visualizing the currently detected object): Camera-Stream -> CoreML Segmentation -> Send the relevant part of the MLShapedArray-Tensor to a MTLComputeShader that returns a MTLTexture -> Show the resulting texture on a 3D object to the user
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CoreVideo + Rosetta still clamps at 60Hz (since macOS 12)
We set the CVDisplayLink on macOS to 0 or 120, and get the following. This then clamps maximum refresh to 60Hz on the 120Hz ProMotion display on a MBP M2 Max laptop. How is this not fixed in 4 macOS releases? CoreVideo: currentVBLDelta returned 200000 for display 1 -- ignoring unreasonable value CoreVideo: [0x7fe2fb816020] Bad CurrentVBLDelta for display 1 is zero. defaulting to 60Hz.
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Metal 4 & Acceleration Structures
I have really enjoyed looking through the code and videos related to Metal 4. Currently, my interest is to update a ReSTIR Project and take advantage of more robust ways to refit acceleration Structures and more powerful ways to access resources. I am working in Swift and have encountered a couple of puzzles: What is the 'accepted' way to create a MTL4BufferRange to store indices and vertices? How do I properly rewrite Swift code to build and compact an Acceleration Structure? I do realize that this is all in Beta and will happily look through Code Samples this Fall. If other guidance is available earlier, that would be fabulous! Thank you
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Sep ’25
Inquiry About Game Center Integration Analytics
Dear Apple Developer Support, I hope this message finds you well. I am a game developer looking to integrate Game Center into our game. Before proceeding, I would like to understand the analytical capabilities available post-integration. Specifically, I am interested in tracking detailed metrics such as: The number of new player downloads driven by Game Center features (e.g., friend challenges, leaderboards, or achievements). Data on user engagement and conversions originating from Game Center interactions. I have explored App Store Connect’s App Analytics but would appreciate clarification on whether Game Center-specific data (e.g., referrals from challenges or social features) is available to measure growth and optimize our strategies. If such data is accessible, could you guide me on how to view it? If not, are there alternative methods or plans to incorporate this in the future? Thank you for your time and assistance. I look forward to your response. Best regards, Bella
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Sep ’25
iPhone Pro Model - RefreshRate
I want to display the refresh rate on the screen of the iPhone (14 Pro Max), but each app of the App Store's "Floating Clock", "Floating Clock Premium" and "Screen Renewal Rate - RefreshRate Realtime" can only display two of 60Hz and 120Hz, and I wonder if it can display numbers of 1Hz, 10Hz, tens of Hz, or more than 3 levels. Does anyone know how to do it?
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Sep ’25
Testing Gamecenter Accounts
HI all, I'm in the early stages of testing a game that will have real-time device-to-device communication using GameCenter. I've read something about setting up GameCenter "sandbox" accounts to test prior to the game's release, but I can't find anything reliable about how to do so. I've found lots of web pages which purport to describe how to do this task, but what they describe seems to be outdated, as the steps don't appear to be available in modern versions of iOS. I'm testing on iOS 18 and 26. Document search isn't helping--I mostly find information on how to set up StoreKit sandbox accounts, which I assume are different things altogether--so if you could point me towards an article that allows me to test a new, unreleased GameKit app between devices, I'd appreciate it. People are developing GameCenter apps, so I know it's possible... advTHANKSance
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Sep ’25
New GameSave API fails, "Couldn’t communicate with a helper application."
I've been playing with the new GameSave API and cannot get it to work. I followed the 3-step instructions from the Developer video. Step 2, "Next, login to your Apple developer account and include this entitlement in the provisioning profile for your game." seems to be unnecessary, as Xcode set this for you when you do step 1 "First add the iCloud entitlement to your game." Running the app on my device and tapping "Load" starts the sync, then fails with the error "Couldn’t communicate with a helper application." I have no idea how to troubleshoot this. Every other time I've used CloudKit it has Just Worked™. Halp‽ Here is my example app: import Foundation import SwiftUI import GameSave @main struct GameSaveTestApp: App { var body: some Scene { WindowGroup { GameView() } } } struct GameView: View { @State private var loader = GameLoader() var body: some View { List { Button("Load") { loader.load() } Button("Finish sync") { Task { try? await loader.finish() } } } } } @Observable class GameLoader { var directory: GameSaveSyncedDirectory? func stateChanged() { let newState = withObservationTracking { directory?.state } onChange: { Task { @MainActor [weak self] in self?.stateChanged() } } print("State changed to \(newState?.description ?? "nil")") switch newState { case .error(let error): print("ERROR: \(error.localizedDescription)") default: _ = 0 // NOOP } } func load() { print("Opening gamesave directory") directory = GameSaveSyncedDirectory.openDirectory() stateChanged() } func finish() async throws { print("finishing syncing") await directory?.finishSyncing() } }
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Sep ’25