I have an AR game using ARKit with SceneKit that works just fine in iOS 17.
In the iOS 18 betas, the AR background image shows black instead of showing the real world. As a result there's no tracking and obviously the whole game is useless.
I narrowed down the issue to showing the Game Center Access Point.
My app has ViewController 1 (VC1) showing the main menu and that's where I want to show the GC Access Point. From there you open VC2 which shows a list of levels. Selecting any level will open VC3 which has the ARScene.
Following is the code I use to start Game Center in VC1:
GKLocalPlayer.local.authenticateHandler = { gcAuthVC, error in
let isGameCenterReady = (gcAuthVC == nil) && (error == nil)
if let viewController = gcAuthVC {
self.present (viewController, animated: true, completion: nil)
}
if error != nil {
print(error?.localizedDescription ?? "")
}
if isGameCenterReady {
GKAccessPoint.shared.location = .topLeading
GKAccessPoint.shared.showHighlights = true
GKAccessPoint.shared.isActive = true
}
}
When switching to VC2 I run GKAccessPoint.shared.isActive = false so that the Access Point will no longer show in any of the following VCs. I tried running it in VC1, VC2, and again in VC3 - it doesn't change anything. Once I reach VC3, the background is black.
If in VC1 I don't run GKAccessPoint.shared.isActive = true, so I don't activate the access point, the behavior is as follows:
If I wait until after the Game Center login animation completes and closes on its own and then I proceed to VC2 and VC3, the camera image will show correctly
If I quickly move to VC2 before the Game Center login animation has completed, so my code will close it by setting active = false, and then I continue to VC3, I will see the black background problem.
So it does look like activating the access point and then de-activating it causes the issue. BTW, if I activate the access point and leave it on in all VCs, the same black background issue persists.
Other than that, when I'm in VC3 with the black background and I switch to another app (so my game moves to the background), when it returns to the foreground, the camera suddenly shows the real world correctly!
I tried to manually reset the AR session by pausing and restarting it, but that didn't change anything. Also, when I check with the debugger, it looks like when the app comes back to the foreground it also doesn't run the session start code.
But something does seem to reset itself so I wonder what that is. Maybe I could trigger the same manually in my cdoe???
I repeat that everything works just fine in iOS 17 and below. This problem only started with the iOS 18 beta (currently on beta 5, but it started in some of the previous betas as well).
So could this be a bug in iOS 18?
As a workaround I could check the iOS version and if it's iOS18 not activate the access point, hoping that the user will not jump to VC2 too quickly, and show my own button which will open Game Center. But I'd rather give the users the full experience with their own avatar and the highlights showing up. Plus, certainly some users will move quickly to VC2 and that will be an awful experience.
Any help would be greatly appreciated. Thanks!