Is the pseudocode below thread-safe? Imagine that the Main thread sets the CAMetalLayer's drawableSize to a new size meanwhile the rendering thread is in the middle of rendering into an existing MTLDrawable which does still have the old size.
Is the change of metalLayer.drawableSize thread-safe in the sense that I can present an old MTLDrawable which has a different resolution than the current value of metalLayer.drawableSize? I assume that setting the drawableSize property informs Metal that the next MTLDrawable offered by the CAMetalLayer should have the new size, right?
Is it valid to assume that "metalLayer.drawableSize = newSize" and "metalLayer.nextDrawable()" are internally synchronized, so it cannot happen that metalLayer.nextDrawable() would produce e.g. a MTLDrawable with the old width but with the new height (or a completely invalid resolution due to potential race conditions)?
func onWindowResized(newSize: CGSize) {
// Called on the Main thread
metalLayer.drawableSize = newSize
}
func onVsync(drawable: MTLDrawable) {
// Called on a background rendering thread
renderer.renderInto(drawable: drawable)
}
Delve into the world of graphics and game development. Discuss creating stunning visuals, optimizing game mechanics, and share resources for game developers.
Selecting any option will automatically load the page
Post
Replies
Boosts
Views
Activity
When running my game in the Unity Editor on Windows platform I get an error:
DllNotFoundException: GameKitWrapper assembly:<unknown assembly> type:<unknown type> member:(null)
Apple.GameKit.DefaultNSErrorHandler.Init () (at ./Library/PackageCache/com.apple.unityplugin.gamekit@0abcad546f73/Source/DefaultHandlers.cs:35)
This is because GameKitWrapper dynamically linked library is not available under Windows platform.
Besides, "Apple Build Settings" are declared under UNITY_EDITOR_OSX and also not available under Windows platform.
Does anyone managed to solve this?
I can't create any breakpoint in my Xcode after I upgraded to macOS 15.4
macOS: Version 15.4 (24E248)
visionOS Simulator: 2.3
Xcode: Version 16.2 (16C5032a)
My app works well without any breakpoints.
But if I create any breakpoint it shows me this:
Couldn't find the Objective-C runtime library in loaded images.
Message from debugger: The LLDB RPC server has crashed. You may need to manually terminate your process. The crash log is located in ~/Library/Logs/DiagnosticReports and has a prefix 'lldb-rpc-server'. Please file a bug and attach the most recent crash log.
Hi everyone,
This project uses PyTorch on an Apple Silicon Mac (M1/M2/etc.), and the goal is to use the MPS backend for GPU acceleration, notes Apple Developer. However, the workflow depends on Float64 (double-precision) floating-point numbers for certain computations, notes PyTorch Forums.
The error "Cannot convert a MPS Tensor to float64 dtype as the MPS framework doesn't support float64. Please use float32 instead" has been encountered, notes GitHub. It seems that the MPS backend doesn't currently support Float64 for direct GPU computation.
Questions for the community:
Are there any known workarounds or best practices for handling Float64-dependent operations when using the MPS backend with PyTorch?
For those working with high-precision tasks on Apple Silicon, what strategies are being used to balance performance with the need for Float64?
Offloading to the CPU is an option, and it's of interest to know if there are any specific techniques or libraries within the Apple ecosystem that could streamline this process while aiming for optimal performance.
Any insights, tips, or experiences would be appreciated.
Thanks in advance,
Jonaid
MacBook Pro M3 Max
Topic:
Graphics & Games
SubTopic:
Metal
Breaking Through PolySpatial's ~8k Object Limit – Seeking Alternative Approaches for Large-Scale Digital Twins
Confirmed: PolySpatial make Doubles MeshFilter Count – Hard Limit at ~8k Active Objects (15.9k Total)
Project Context & Research Goals
I’m developing an industrial digital twin application for Apple Vision Pro using Unity’s PolySpatial framework (RealityKit rendering in Unbounded_Volume mode). The scene contains complex factory environments with:
Production line equipment Many fragmented grid objects need to be merged.)
Dynamic product racks (state-switchable assets)
Animated worker avatars
To optimize performance, I’m systematically testing visionOS’s rendering capacity limits. Through controlled stress tests, I’ve identified a critical threshold:
Key Finding
When the total MeshFilter count reaches 15,970 (system baseline + 7,985 user-created objects × 2 due to PolySpatial cloning), the application crashes consistently. This suggests:
PolySpatial’s mirroring mechanism effectively doubles GameObject overhead
An apparent hard limit exists around ~8k active mesh objects in practice
Objectives for This Discussion
Verify if others have encountered similar limits with PolySpatial/RealityKit
Understand whether this is a:
Memory constraint (per-app allocation)
Render pipeline limit (Metal draw calls)
Unity-specific PolySpatial behavior
Explore optimization strategies beyond brute-force object reduction
Why This Matters
Industrial metaverse applications require rendering thousands of interactive objects . Confirming these limits will help our team:
Design safer content guidelines
Prioritize GPU instancing/LOD investments
Potentially contribute back to PolySpatial’s optimization
I’d appreciate insights from engineers who’ve:
Pushed similar large-scale scenes in visionOS
Worked around PolySpatial’s cloning overhead
Discovered alternative capacity limits (vertices/draw calls)
Is it possible to start screen recording (through Control Center) without user prompt?
I mean to ask user permission for the first time and after that to start and stop recording programmatically only?
I need to record screen only for specific events.
In the CanyonCrosser example project, some RealityKit systems are implemented as classes while others are structs. What’s the reason for using different types?
I noticed that MTLPixelFormat has this cases:
case r32Float = 55
case rg32Float = 105
case rgba32Float = 125
But no case rgb32Float. What's the reason for such a discrimination?
Issues building Unity plug-in project: Cannot locate native library Apple.Core/Apple.GameKit for iOS
I'm having issues getting a well built package from the Apple Unity Plug-in project.
When building the my game project in Unity the following error is printed to the console:
Apple.Core.AppleNativeLibraryUtility] Cannot locate a Debug or Release Apple.Core native library for iOS.
Please ensure that the build invocation (build.py, xcodebuild, or Xcode) compiled cleanly and that the build was configured to support Debug on iOS.
As far as I can tell the build did compile cleanly, but I might be missing something.
If anyone can see what I'm doing wrong or has any insight it would be greatly appreciated.
Setup is the following:
macOS Tahoe 26 Beta
Xcode-beta Version 26.0 beta 3 (17A5276g)
Unity Plug-in branch: 2025-beta1
Unity game project version: 2022.3.60f
M1 Macbook Pro
The built packages have been imported into the game project through the Unity Package Manager using the tarball option pointing to the built packages from the Unity Plug-in project.
The Unity Plug-in project has been built using the build.py file with the following:
python3 build.py -m iOS iPhoneSimulator -p Core GameKit CoreHaptics GameController -k all
The output is available in the attached file.
build-output.txt
Here's an image of the NativeLibraries~ folder inside the built Apple.Core package.
Dear Apple, there is still no support for WebGPU via WebView. Do you have a roadmap on when you plan to support it? That would be very helpful to release our new game.
Topic:
Graphics & Games
SubTopic:
General
Hi everyone
I'm experiencing an issue with iPadOS 26 regarding multi-touch gesture detection. When performing a quick four-finger gesture (tap and swipe), the system often fails to recognize the input. This especially affects multi-touch gestures, such as rhythm games with difficult levels.
Steps to Reproduce:
Place four fingers on the screen.
Perform a quick tap or a quick horizontal swipe (like the one used to switch apps).
Observe whether the gesture is ignored or detected inconsistently.
Expected Behavior:
4-finger multitouch gestures should be recognized regardless of gesture speed, just like previous iPadOS versions.
Actual Behavior:
Gestures fail to be detected when executed quickly—same gestures still work, and miss notes in rhythm games.
You can check out my posts on Twitter/x and Facebook: [https://x.com/kokona_fwa/status/1978131164104728949?s=61]
Facebook: [https://m.facebook.com/groups/idipad/permalink/24438964899058806/?]
I use unity 2020.3.48f1 to develop a game; trying to implement Apple Services integration I use Apple unity plugins(https://github.com/apple/unityplugins) Using latest version of unity plugins I getting error in Unity project after plugin import It say "Not allowed platform VisionOS" When I tryed to use older version of the plugins I getting error on runtime when calling "var fetchItemsResponse = await GKLocalPlayer.Local.FetchItems();" in line 42 it drop EXC_BAD_ACCESS(code=257, address=0x0000...) error I tryed to use different commits from official repositorys and even custom branches of apple unity plugins like (https://github.com/muZZkat/unityplugins/tree/muzzkat/fix-fetch-items) but it did not help
There is whole my script which trying to use apple unuity plugins
using System.Threading.Tasks;
using UnityEngine;
using System.Collections;
using System;
using Apple.GameKit;
using UnityEngine.UI;
public class TheScript : MonoBehaviour
{
[SerializeField]
InputField otp;
string Signature;
string TeamPlayerID;
string Salt;
string PublicKeyUrl;
string Timestamp;
void Start()
{
StartCoroutine(Call());
}
private IEnumerator Call()
{
yield return new WaitForSeconds(5);
Login();
}
public async Task Login()
{
otp.text += $"Loginig... ";
if (!Apple.GameKit.GKLocalPlayer.Local.IsAuthenticated)
{
try
{
var player = await GKLocalPlayer.Authenticate();
var localPlayer = GKLocalPlayer.Local;
TeamPlayerID = localPlayer.TeamPlayerId;
var fetchItemsResponse = await GKLocalPlayer.Local.FetchItems();
Signature = Convert.ToBase64String(fetchItemsResponse.GetSignature());
PublicKeyUrl = fetchItemsResponse.PublicKeyUrl;
otp.text += $"Team Player ID: {TeamPlayerID} ";
otp.text += $"PublicKeyUrl: {PublicKeyUrl} ";
}
catch(Exception e)
{
otp.text += $"Error: " + e.Message;
}
}
else
{
Debug.Log("AppleGameCenter player already logged in.");
}
}
async Task SignInWithAppleGameCenterAsync(string signature, string teamPlayerId, string publicKeyURL, string salt, ulong timestamp)
{
}
}
Hi team, I'm looking for the RealityKit debugger in Xcode 26 beta 3. I'm running a RealityKit app on my iPad running iPadOS 26 b3, but the debugger option is not there in Xcode.
I'm trying to use MTLBinaryArchive. I collected a BinaryArchive from one device and used metal-tt to translate it for all supported iPhone devices, ranging from iPhone 7 Plus to iPhone 16.
However, this BinaryArchive is quite large, around 1.5GB uncompressed, and about 500MB compressed in the IPA. I'm wondering how to address the size issue.
I watched the WWDC 2022 video, which mentioned that the operating system or app installation process would handle compatibility. Does this compatibility support different GPU chips? I tried installing an IPA with a BinaryArchive collected only from an iPhone 12 on an iPhone 13, but the BinaryArchive didn't take effect.
I also saw that Apple supports App Thinning. However, it seems that resources in the Asset Catalog cannot be accessed via URL, and creating an MTLBinaryArchive requires a URL. Is it possible for MTLBinaryArchive to be distributed through App Thinning?
The WWDC 2022 video also mentioned using the -Os optimization flag to reduce size. Can this give an estimate of how much compression it would achieve? Are there any methods to solve the BinaryArchive size issue without impacting performance?
Topic:
Graphics & Games
SubTopic:
Metal
I have tried every combination of suggestions to get a skybox to appear. Using swiftUI, realityKit and iOS. Non immersive environment. Does anyone have code that works to display a skybox.
When i use a do/catch loop i get environmentResource not found. I have checked the syntax, ensured the folder is referencing the target, used the same name for the folder as the file, the file is a .hdr (i assume this is supported), i have moved the file folder to the top level - no change.
Hi,
I've just moved my SpriteKit-based game from UIView to SwiftUI + SpriteView and I'm getting this mesage
Adding 'GCControllerView' as a subview of UIHostingController.view is not supported and may result in a broken view hierarchy. Add your view above UIHostingController.view in a common superview or insert it into your SwiftUI content in a UIViewRepresentable instead.
Here's how I'm doing this
struct ContentView: View {
@State var alreadyStarted = false
let initialScene = GKScene(fileNamed: "StartScene")!.rootNode as! SKScene
var body: some View {
ZStack {
SpriteView(scene: initialScene, transition: .crossFade(withDuration: 1), isPaused: false , preferredFramesPerSecond: 60)
.edgesIgnoringSafeArea(.all)
.onAppear {
if !self.alreadyStarted {
self.alreadyStarted.toggle()
initialScene.scaleMode = .aspectFit
}
}
VirtualControllerView()
.onAppear {
let virtualController = BTTSUtilities.shared.makeVirtualController()
BTTSSharedData.shared.virtualGameController = virtualController
BTTSSharedData.shared.virtualGameController?.connect()
}
.onDisappear {
BTTSSharedData.shared.virtualGameController?.disconnect()
}
}
}
}
struct VirtualControllerView: UIViewRepresentable {
func makeUIView(context: Context) -> UIView {
let result = PassthroughView()
return result
}
func updateUIView(_ uiView: UIView, context: Context) {
}
}
class PassthroughView: UIView {
override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
for subview in subviews.reversed() {
let convertedPoint = convert(point, to: subview)
if let hitView = subview.hitTest(convertedPoint, with: event) {
return hitView
}
}
return nil
}
}
Hi, following the recent deprecation of SceneKit, I'm trying to move a couple of my SceneKit projects to RealityKit.
One thing I can't seem to find is how to change the content scale factor when using a RealityView in SwiftUI. It was really easy to do in SceneKit with just a SCNView property, and it seems that it's also possible when using ARView, but I can't find a way to do it with a RealityView. Maybe it's a SwiftUI limitation?
Topic:
Graphics & Games
SubTopic:
RealityKit
Hi all,
I've encountered a potential issue with how the winding order of geometry is handled when their transformations involve negative scaling.
I created a simple test asset, a single triangle, to demonstrate this. The triangle's vertices are defined in a counter-clockwise ("right-handed") winding order, and its transform has a negative scale on the X-axis. According to the OpenUSD specification, this negative determinant in the transformation matrix should effectively reverse the winding order of the geometry:
However, any given gprim's local-to-world transformation can flip its effective orientation, when it contains an odd number of negative scales. This condition can be reliably detected using the (Jacobian) determinant of the local-to-world transform: if the determinant is less than zero, then the gprim's orientation has been flipped, and therefore one must apply the opposite handedness rule when computing its surface normals (or just flip the computed normals) for the purposes of hidden surface detection and lighting calculations.
When I view the asset in tools like Blender or Preview on macOS, it behaves as expected. The triangle's effective orientation is flipped to CW.
However, when the same asset is viewed in Reality Composer Pro or with QuickLook on iOS, its effective orientation remains CCW. In other words, the triangle faces the opposite direction.
My questions for the community and Apple are:
Is this behavior in RealityKit a known issue?
If this is a known issue, is there official guidance for DCC tools on how to export USDZ assets to ensure they appear correctly in the Apple ecosystem?
Any insights or recommendations would be greatly appreciated.
Reproduce
Same SIM card with 4G, same testing location, connected to the same server, xcode debugging game applications, network/profile retrotransmitted, Avg round trip to view data
iPhone17, Turn off 4G and turn on WiFi. All the above indicators are acceptable
iPhone17, Turn on 4G, turn off WiFi, retry with retransmission and very high Avg round trip
iPhone14-16, Turn on 4G and turn off WiFi. All the above indicators are acceptable
App
Unity3d project
.netframe4.0
C# Socket
Other
Many developers in Chinese forums have provided feedback on this issue
Hello -
Upon enabling debug mode for GameKit configuration for my iOS app, I do not see any devices (my iPhone or simulators) in the device list within the "Manage Game Progress" debug tool. I only see my Mac as a device. Is there any trick to this or a way to add devices to this list?
Thank you