I'm trying to pass a buffer of float2 items from CPU to GPU.
In the kernel, I can provide a parameter for the buffer:
device const float2* values
for example.
How do I specify float2 as the type for the MTL::Buffer?
I managed to get the code to work by "cheating" by defining a simple class that has the same data members as a float2, but there is probably a better way.
class Coord_f { public: float x{0.0f}; float y{0.0f}; };
then using code to allocate like this:
NS::TransferPtr(device->newBuffer(n_elements * sizeof(Coord_f), MTL::ResourceStorageModeManaged))
The headers for metal-cpp do not appear to define vector objects like float2, but I'm doubtless missing something.
Thanks.
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New to achievements. I added them in App Store Connect and want to test them.
Apple Documentation says this:
"Before you begin testing your GameKit configuration, you need to enable Debug Mode. In Xcode, choose Product > Scheme > Edit Scheme. From the Run configuration, select Options and toggle Enable Debug Mode.
To begin testing your achievement configuration, open the game Progress Manager. In Xcode, choose Debug > GameKit > Manage Game Progress."
Sounds easy enough, but there is no "GameKit" under Debug in Xcode 16.2.
Topic:
Graphics & Games
SubTopic:
GameKit
Hello,
On macOS 26 (Tahoe), when building a OSX app that includes GameKit code, calling GKLocalPlayer.local.authenticateHandler shows the "Sign In to Game Center" alert (e.g. didShowFullscreenSignIn) — even if the app does not have the Game Center capability enabled or any related entitlement (com.apple.developer.game-center).
This alert only appears when the user is not signed in to Game Center in system settings.
However, when testing the same code path on iOS app built with macOS 26 (Tahoe), the alert does not appear unless the proper capability and entitlement are included.
This behavior is different from macOS 15 (Sequoia) + Xcode 15.x. Prior to the update, Game Center features did not work at all even with the OSX app without Capability and Entitlements.
Steps to Reproduce
Create a new OSX app target (App Sandbox enabled, no Game Center capability).
Add minimal GameKit code:
GKLocalPlayer.local.authenticateHandler = { _, _, _ in }
Build OSX app and run on macOS 26 (Tahoe).
Ensure Game Center is signed out in System Settings.
Observe: “Sign In to Game Center” alert appears automatically.
Expected Behavior
When Game Center capability and entitlement are not present, authenticateHandler should fail silently, and no signIn alert should appear.
Actual Behavior
On OSX app, the Game Center signIn UI appears even without any Game Center capability or entitlement.
On iOS app, this alert does not appear.
*Build Configuration: built with the same condition. (macOS 26 + Xcode 26)
Question
Could you please confirm whether this behavior is an intentional change in macOS 26 or a bug only for OSX apps in the GameKit authentication flow?
Thank you.
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.
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)
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.
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?
Topic:
Graphics & Games
SubTopic:
Metal
When using simd_inverse functions, the same input yields different results on different devices.
On the Mac mini with M4 pro and M3 ultra, the result is
But on the Mac mini of M2 ultra, the result is
Our APP has integrated 3D function, in order to reduce the memory occupation of the APP in the background, we will uninstall the 3D after the APP enters the background. However, the uninstall also causes problems. When the uninstall process is executed in the background, the app will briefly trigger the background GPU rendering error warning with the error warning code:
OGPUMetalError: Insufficient Permission (to submit GPU work from background) (00000006:kIOGPUCommandBufferCallbackErrorBackgroundExecutionNotPermitted)
Execution of the command buffer was aborted due to an error during execution. Insufficient Permission (to submit GPU Work from background) (00000006: kIOGPUCommandBufferCallbackErrorBackgroundExecutionNotPermitted) excuse me this warning system will tighten APP permissions background? For example, limit or shorten the background survival time of the APP. In addition, will the background refresh function fail, resulting in the failure of Bluetooth Ibeacon activation?
Topic:
Graphics & Games
SubTopic:
Metal
Helle there
Currently, I’m attempting to create an interactive learning application with a 3D view. I’ve discovered the framework SceneKit, but I lack the necessary knowledge to animate, load and moving objects. Could someone kindly suggest some good articles or tutorials on this topic?
I work on a team that provides an SDK for another game to handle various tasks like authentication. They are experiencing a case where devices using iOS 17 are failing to authenticate with GameCenter, receiving the message "The requested operation could not be completed because local player has not been authenticated." We imagine this is because they still have some setup to finish regarding GameCenter itself, and we're working with them to take care of that.
However, on iOS 18, their app ends up waiting indefinitely for GameCenter authentication messages that it never receives. That's where we're puzzled. We expect them to have the same outcome regardless of OS version.
We initiate GameCenter authentication by setting an authenticateHandler after some initial application setup. The handler has code to account for UI, errors, and successful authentication.
On iOS 17, it's clear that it's getting called as expected because they receive an indication that the player isn't authenticated. But on iOS 18, it looks like the same handler code on iOS 18 isn't being called at all. Are there differences in how iOS 18 interacts with the authenticationHandler that we somehow aren't accounting for? Or is there potentially something else that we're doing incorrectly that is manifesting only on iOS 18?
Here's a simplified version of our login function code (in Obj-C++). There is no OS-specific code, and the job that owns this function does stay in scope until after authentication is complete.
void beginLogin()
{
// Snip: Check if the user is already logged in.
// Snip: Prevent multiple concurrent calls to this function.
auto authenticateHandler = ^(UIViewController* gcViewController, NSError* error)
{
if (gcViewController != nil)
{
// Snip: Display the UI
}
else if (error != nil)
{
// Snip: Handle the error.
}
else
{
if ([[GKLocalPlayer localPlayer] isAuthenticated])
{
// Snip: Handle successful authentication.
}
else
{
// Snip: Handle other case.
}
}
};
[[GKLocalPlayer localPlayer] setAuthenticateHandler: authenticateHandler];
}
On an iPad running iPadOS 26 beta 4, when tapping the Game Center Access Point, the overlay doesn’t show the configured achievements, leaderboards or challenges.
I should specify this is an in-development app and the achievements and leaderboards are in the “Not Live” state, however they show on other devices running iOS 18 in the Access Point UI.
Anyone else having this issue? If so, how should I test achievements and leaderboards while iOS 26 beta is out?
The UI looks like this on iPadOS 26:
I’m running into unexpected problems with the Unity GameKit plugin setup with the new Activities. I didn’t see anyone else mentioning these issues, so my guess is that it’s a problem with my setup.
The authentication (GKLocalPlayer.Authenticate()) works as expected, but any call to the new GameActivity functionality (e.g. GKGameActivityDefinition.LoadGameActivityDefinitions() or GKGameActivity.WantsToPlay) gives me an exception with a 'UnsupportedOperationForOSVersion' reason despite it running on an iOS 18.6.1 device.
I’m using a completely empty Unity 2022.3.62f1 project that only contains the official authentication example, followed by an event handler for activities from another example and the Unity core and gamekit plugins.
The setup:
macOS 15.6
Xcode 26 beta 6 (also tried with 5)
Physical iPhone device running iOS 18.6.1
Unity 2022.3.62f1, which satisfies the requirements
Unity plugin, Xcode setup, and build steps:
I Followed the official beta branch build steps for Unity plugins with python3 build.py -m iOS iPhoneSimulator macOS -p Core GameKit which ran through after a slight modification for the macOS target that somehow contained an unknown team reference for the GameKitWrapper project, which I changed to not reference a team and use ‘sign to run locally’, as was the case for the other packages. As far as I understood the macOS version is not strictly necessary either way just for running it on a local iOS device(?)
I Imported these as tarball packages into the empty Unity 2022.3.62f1 project as per the official instructions, which seems to work as expected
Added a single script with the mentioned example code added in a MonoBehavior.Start
Building in Unity works as expected as well, creating the Xcode project
The Unity-iPhone target has the GameKit framework linked (’do not embed’) and the GameCenter capability was added automatically as expected
The GameKit framework seems to not be added to the UnityFramework target, but I don’t think this is necessary? Quickly testing this with the GameKit framework added there as well didn’t make a difference
The linked GameKit framework is indeed the expected Xcode 26 beta version
I can then build and run this on the physical iPhone iOS 18.6.1 device, where I get an ‘UnsupportedOperationForOSVersion’ as soon as I try to subscribe to deeplinking events (GKGameActivity.WantsToPlay) or use other GameKit Activity functionality from the official examples:
// log showing that it's actually running on iOS 18.6:
[Apple.Core Plug-In Runtime] Availability Runtime Environment: iOS 18.6
Apple.Core.Availability:OnApplicationStart()
// and the exception I get:
GameKitException: Code=-7 Domain=GKErrorDomain Description=The operation couldn’t be completed. (GKErrorDomain error -7.) (UnsupportedOperationForOSVersion)
at Apple.GameKit.DefaultNSErrorHandler.ThrowNSError (System.IntPtr nsErrorPtr) [0x00000] in <00000000000000000000000000000000>:0
Rethrow as TypeInitializationException: The type initializer for 'Apple.GameKit.GKGameActivity' threw an exception.
I unfortunately didn’t find any clues as to why this happens and how to resolve it on this forum or otherwise.
Changing the minimum iOS version - up to 18.6 from the previously used (Unity export default) 12.0 for any and all targets - did not yield a different result
I'd rather not update the phone to use the iOS 26 beta, though as far as I understood this is not necessary
Any pointers to what I might be missing or doing wrong are greatly appreciated!
Thank you very much in advance!
In swipe-driven games, a first downward swipe starting near the home indicator can trigger Reachability, even when using preferredScreenEdgesDeferringSystemGestures = .bottom and prefersHomeIndicatorAutoHidden = true. This causes the app to slide down to half screen and breaks gameplay. Please consider an API to temporarily defer Reachability while a custom gesture is active (similar to existing system gesture deferral), without disabling accessibility globally.
Environment:
Devices: iPhones with Home Indicator (Face ID)
Why this matters:
Bottom-origin swipes are core in many games (flick shots, slingshot, physics toss, bottom sheets). Current workarounds degrade UX and discoverability, and players still accidentally trigger Reachability.
Feedback Assistant Post
Topic:
Graphics & Games
SubTopic:
General
Hello,
We are experiencing an issue with apparent lag or latency when interacting with objects in Unity using the XR Interaction Toolkit. Even when interactables are configured with the Movement Type set to Instantaneous, objects exhibit a noticeable delay when following hand movement. This issue is particularly apparent when the hand moves at higher speeds.
We would like to know: is any additional configuration required, or is there something else we need to do to resolve this?
Thank you very much for your assistance.
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 shipped an App Store build that signs in to Game Center using the Apple Unity Plugins (GameKit). The login banner appears, but my app still doesn’t show up in Game Center’s “All activity” (You started playing XXX 2d ago)
What I’ve done
Call await GKLocalPlayer.Authenticate();
“Game Center” is enabled for the current version in App Store Connect
Confirmed: other App Store games do appear under “All Activity” on the same device/account
Timeline: This is the first version that enables Game Center (not the app’s first release), and it has been about 2 hours since this build went live.
Questions
Is authentication alone sufficient for “Recently Played,” or is at least one Game Center component (leaderboards, achievements, activities, multiplayer) required?
Is there a typical propagation delay before “Recently Played” starts showing a newly enabled app/version?
Is there anything else I should configure in App Store Connect or entitlements to make “Recently Played” visible?
Thanks for any help.
I have 2 planes with textures on. I want these planes to intersect [ –|– ], and I want the blend mode to be additive. Currently I get z fighting on the planes, and I can't see how to set blend modes.
I've done this before in Unity and Godot in a fairly straight forward manner.
How do I accomplish this with RealityKit, preferably using code only (my scene is quite dynamic)?
Do I need to do it with a shader manually? How can I stop the z fighting?
Post can be removed.
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