We have a macOS app (not yet released, but in use by ourselves), that provides scoreboards for streaming sport events.
Today it is expected, that there are nice animations for goals, etc. We are streaming using NDI, which requires a CVPixelBuffer for each frame.
We currently create these animations using CABasicAnimation, CAAnimation and CAKeyframeAnimation. In addition we use ScreenCaptureKit to generate the frames.
This works fine with 25/30 fps, as long as the window where our animations are performed in is visible. But this is not what it should be. We have a smaller window as main app window and control display performing the animations in reduced size, while the streaming animations need to be in HD format and later maybe in 4K.
When using an offscreen window, the animations are not calculated. We get 1 frame per second or so. So we actually have to connect an external display to the MacBook and open the large windows there. Ugly solution.
Do we use a completely wrong approach? Or is there a way to tell the macOS to perform the animations although it is an offscreen window?
If it cannot work that way, what is an alternative?
Delve into the world of graphics and game development. Discuss creating stunning visuals, optimizing game mechanics, and share resources for game developers.
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The following minimal snippet SEGFAULTS with SDK 26.0 and 26.1. Won't crash if I remove async from the enclosing function signature - but it's impractical in a real project.
import Metal
import MetalPerformanceShaders
let SEED = UInt64(0x0)
typealias T = Float16
/* Why ran in async context? Because global GPU object,
and async makeMTLFunction,
and async makeMTLComputePipelineState.
Nevertheless, can trigger the bug without using global
@MainActor
let myGPU = MyGPU()
*/
@main
struct CMDLine {
static func main() async {
let ptr = UnsafeMutablePointer<T>.allocate(capacity: 0)
async let future: Void = randomFillOnGPU(ptr, count: 0)
print("Main thread is playing around")
await future
print("Successfully reached the end.")
}
static func randomFillOnGPU(_ buf: UnsafeMutablePointer<T>, count destbufcount: Int) async {
// let (device, queue) = await (myGPU.device, myGPU.commandqueue)
let myGPU = MyGPU()
let (device, queue) = (myGPU.device, myGPU.commandqueue)
// Init MTLBuffer, async let makeFunction, makeComputePipelineState, etc.
let tempDataType = MPSDataType.uInt32
let randfiller = MPSMatrixRandomMTGP32(device: device, destinationDataType: tempDataType, seed: Int(bitPattern:UInt(SEED)))
print("randomFillOnGPU: successfully created MPSMatrixRandom.")
// try await computePipelineState
// ^ Crashes before this could return
// Or in this minimal case, after randomFillOnGPU() returns
// make encoder, set pso, dispatch, commit...
}
}
actor MyGPU {
let device : MTLDevice
let commandqueue : MTLCommandQueue
init() {
guard let dev: MTLDevice = MPSGetPreferredDevice(.skipRemovable),
let cq = dev.makeCommandQueue(),
dev.supportsFamily(.apple6) || dev.supportsFamily(.mac2)
else { print("Unable to get Metal Device! Exiting"); exit(EX_UNAVAILABLE) }
print("Selected device: \(String(format: "%llX", dev.registryID))")
self.device = dev
self.commandqueue = cq
print("myGPU: initialization complete.")
}
}
See FB20916929. Apparently objc autorelease pool is releasing the wrong address during context switch (across suspension points). I wonder why such obvious case has not been caught before.
Hi everyone,
I’m currently learning about ParticleEmitterComponentParticleEmitterComponent and exploring the sample app provided in the Simulating particles in your visionOS app documentation.
In the sample app, when I set the EmitterPreset to fireworks from the settings panel on the left side of the window and choose SystemImage, I noticed two issues:
The image applied to mainEmitter appears clipped or cropped.
The image on spawnedEmitter does not update to the selected SystemImage.
What I want to achieve:
Apply the same SystemImage to both mainEmittermainEmitter and spawnedEmitterspawnedEmitter so that it displays correctly without clipping.
Remove the animation that changes the size of spawnedEmitterspawnedEmitter over time and keep it at a constant size.
Could someone explain which properties should be adjusted to achieve this behavior? Any guidance or examples would be greatly appreciated.
Thanks in advance!
My app is live but the leaderboards still aren’t updating. App was built with unreal engine 5 with blueprints. I have the leaderboard stat info entered into the node for write integer to leaderboard and a node for show platform specific leaderboard. The leaderboards are shown as live on app connect.
When I run the app, the Game Center login functions and the leaderboard interface launches as expected but it just lists a group of friends to invite. There are no scores listed and it says number of players 0 even though I have scored on two different devices and accounts. I have the Game Center entitlement added in Xcode. Not sure where else to look.
I have a game built in Unreal Engine 5.6 which uses tilt motion controls to rotate an object. I've restricted the app to only run in portrait for iPhone, and everything works fine, however for iPad I've had a few issues relating to multitasking and I can't seem to solve it.
Forcing the app to portrait only still allows the app to run in landscape mode, but shows black bars either side of the game, and the axes for the motion controls are incorrect. X becomes Y and Y becomes X, and there's no way for my app to know which orientation it is because the container is still technically portrait.
Allowing my game to run in all orientations makes the whole app more presentable, it doesn't add black bars and the game is still functional and I'm able to map the controls correctly because the game knows it's landscape rather than portrait.
The problem with allowing my app to run in landscape mode is if multitasking is enabled on the ipad, you can resize the app to be portrait, and then I run into the same problem again where the game thinks it's portrait mode and all of the axes are wrong again.
I tried getting the true orientation of the device rather than the scene, but the game is intended to be played flat so instead of returning the orientation of the OS the orientation is FaceUp, which doesn't help.
I need to either disable multitasking or find a way of getting the orientation of the OS (not the scene or the device). I haven't found how to get the OS orientation so I've been trying to disable multitasking.
I've got Requires Fullscreen true and UIApplicationSupportsMultipleScreens false in my info.plist but my iPad still seems to allow the window to be resized in landscape view. Opening the IOS workspace of my project Requires Fullscreen is ticked but under that it says "Supports Multiple Windows" and the arrow button next to it takes my to my info.plist values, but no indication of how I can change it.
I'm using Unreal Engine 5.6 and Xcode 16.0. Xcode is old I know, but this version of unreal engine doesn't seem to support any newer.
We used below method to resize image while compress the image,
Below method is correct or need to do the correction in method or "CGBitmapContextCreate"
-(UIImage *)resizeImage:(UIImage *)anImage width:(int)width height:(int)height
{
CGImageRef imageRef = [anImage CGImage];
CGImageAlphaInfo alphaInfo = CGImageGetAlphaInfo(imageRef);
if (alphaInfo == kCGImageAlphaNone)
alphaInfo = kCGImageAlphaNoneSkipLast;
CGContextRef bitmap = CGBitmapContextCreate(NULL, width, height, CGImageGetBitsPerComponent(imageRef), 4 * width, CGImageGetColorSpace(imageRef), alphaInfo);
CGContextDrawImage(bitmap, CGRectMake(0, 0, width, height), imageRef);
CGImageRef ref = CGBitmapContextCreateImage(bitmap);
UIImage *result = [UIImage imageWithCGImage:ref];
CGContextRelease(bitmap);
CGImageRelease(ref);
return result;
}
Hello!
I have a question about how thread groups work with tile shading. When running "traditional" compute, I get to choose both thread group size and the grid size. However, when using tile shading kernel I only have dispatchThreadsPerTile method - this controls how many threads will be ran in each tile. So far so good, but what about thread groups?
The examples in video "Tile Shading on A11" seem to suggest that there will be only one thread group per tile. In the video, [[thread_index_in_threadgroup]] is called "local_id" and it is used to access the image block.
I assume this is the default configuration. So when one does the following:
Creates MTLRenderPassDescriptor with tileWidth set to W and tileHeight set to H
Fires up the tile shading kernel using dispatchThreadsPerTile with MTLSize size = { W, H, 1 }
I understand that the result is 1-to-1 mapping between the tile "pixels" and kernel threads. Now, what I would like to do is to have more than one thread group there. I want this for performance reasons: I have a certain compute kernel which I know executes very well with small thread group size. In fact, { 32, 1, 1 } seems to be the fastest. My understanding is that even if I set tile size to 16x16, and so I am executing 256 threads there, there will only be one SIMD group active in a thread group. Meaning that this SIMD group has to execute 8 times over the tile.
Is it possible somehow? Or perhaps the limitations of the API are pointing at the limitations of hardware itself, and if I want to execute with SIMD group sized thread groups I have to use "traditional" compute encoder?
Will be grateful for help.
Michał
Problem Description
I'm encountering an issue with SCNTechnique where the clearColor setting is being ignored when multiple passes share the same depth buffer. The clear color always appears as the scene background, regardless of what value I set. The minimal project for reproducing the issue: https://www.dropbox.com/scl/fi/30mx06xunh75wgl3t4sbd/SCNTechniqueCustomSymbols.zip?rlkey=yuehjtk7xh2pmdbetv2r8t2lx&st=b9uobpkp&dl=0
Problem Details
In my SCNTechnique configuration, I have two passes that need to share the same depth buffer for proper occlusion handling:
"passes": [
"box1_pass": [
"draw": "DRAW_SCENE",
"includeCategoryMask": 1,
"colorStates": [
"clear": true,
"clearColor": "0 0 0 0" // Expecting transparent black
],
"depthStates": [
"clear": true,
"enableWrite": true
],
"outputs": [
"depth": "box1_depth",
"color": "box1_color"
],
],
"box2_pass": [
"draw": "DRAW_SCENE",
"includeCategoryMask": 2,
"colorStates": [
"clear": true,
"clearColor": "0 0 0 0" // Also expecting transparent black
],
"depthStates": [
"clear": false,
"enableWrite": false
],
"outputs": [
"depth": "box1_depth", // Sharing the same depth buffer
"color": "box2_color",
],
],
"final_quad": [
"draw": "DRAW_QUAD",
"metalVertexShader": "myVertexShader",
"metalFragmentShader": "myFragmentShader",
"inputs": [
"box1_color": "box1_color",
"box2_color": "box2_color",
],
"outputs": [
"color": "COLOR"
]
]
]
And the metal shader used to display box1_color and box2_color with splitting:
fragment half4 myFragmentShader(VertexOut in [[stage_in]],
texture2d<half, access::sample> box1_color [[texture(0)]],
texture2d<half, access::sample> box2_color [[texture(1)]]) {
half4 color1 = box1_color.sample(s, in.texcoord);
half4 color2 = box2_color.sample(s, in.texcoord);
if (in.texcoord.x < 0.5) {
return color1;
}
return color2;
};
Expected Behavior
Both passes should clear their color targets to transparent black (0, 0, 0, 0)
The depth buffer should be shared between passes for proper occlusion
Actual Behavior
Both box1_color and box2_color targets contain the scene background instead of being cleared to transparent (see attached image)
This happens even when I explicitly set clearColor: "0 0 0 0" for both passes
Setting scene.background.contents = UIColor.clear makes the clearColor work as expected, but I need to keep the scene background for other purposes
What I've Tried
Setting different clearColor values - all are ignored when sharing depth buffer
Using DRAW_NODE instead of DRAW_SCENE - didn't solve the issue
Creating a separate pass to capture the background - the background still appears in the other passes
Various combinations of clear flags and render orders
Environment
iOS/macOS, running with "My Mac (Designed for iPad)"
Xcode 16.2
Question
Is this a known limitation of SceneKit when passes share a depth buffer? Is there a workaround to achieve truly transparent clear colors while maintaining a shared depth buffer for occlusion testing?
The core issue seems to be that SceneKit automatically renders the scene background in every DRAW_SCENE pass when a shared depth buffer is detected, overriding any clearColor settings.
Any insights or workarounds would be greatly appreciated. Thank you!
I have a question I guess more for the Apple team.
But why are there no totally 3D experiences for the Vision Pro lineup?
I know they have given us tools to implement unity 3D games into iPhone and I guess you can also build it in RealityKit. But why at this moment are 3D games limited to just iPad and iPhone and can't you bring that into Vision Pro?
Just to explain. When I say a totally 3D game, I mean games like Gorn. I mean the Vision Pro is definitely powerful enough, but it just feels limited to tabletop games and AR games.
Is this something Apple is thinking about implementing?
Topic:
Graphics & Games
SubTopic:
RealityKit
Tags:
ARKit
Reality Composer
RealityKit
Reality Composer Pro
I have an odd bug, if I use initWithFrame as the init routine for NSView subclass that uses layers I don't see this bug.
But if I embedded this view into a storyboard with a .nib file and use initWithCoder, I need to return true on
(BOOL) contentsAreFlipped
From the NSView subclass
If I don't the CALayer actually renders from 0,0 from the view upwards and off the window.
The frame sizes for the NSView and the CALayer are good.. when I see them in updateLayer.
Obviously I have a fix.. but I would like to understand why.
Topic:
Graphics & Games
SubTopic:
General
I have noticed that the performance drop on SpriteKit-based projects running on iOS 26 is still ongoing
With iOS 26 back in Sep 2025 a framerate problem was introduced. My app was always running smoothly with 60fps even on very old devices suddenly started to stutter with 40fps - and lower on a rather normal iPhone 13.
This problem continued with BETA 26.1
The problem was fixed in 26.2.
But 26.3 brought the problem back and its still ongoing with 26.4 of yesterday
This is easily reproducible with a very simple example
//
// BareboneSpriteKitApp.swift
// BareboneSpriteKit
//
// Created by Bernd Beyreuther on 24.02.26.
//
import SwiftUI
import SpriteKit
@main
struct BareboneSpriteKitApp: App {
var body: some Scene {
WindowGroup {
BareboneSceneView()
}
}
}
final class BareboneScene: SKScene {
override func didMove(to view: SKView) {
size = view.bounds.size
scaleMode = .resizeFill
anchorPoint = CGPoint(x: 0.5, y: 0.5)
backgroundColor = .darkGray
let s = SKSpriteNode(color: .cyan, size: CGSize(width: 64, height: 64))
addChild(s)
let action = SKAction.rotate(byAngle: .pi, duration: 2)
s.run(.repeatForever(action))
let t = SKLabelNode(text: deviceInfoString())
t.fontSize = 15
t.position.y = -100
addChild(t)
}
}
struct BareboneSceneView: View {
var body: some View {
SpriteView(
scene: BareboneScene(),
debugOptions: [.showsFPS]
)
.ignoresSafeArea()
}
}
func deviceInfoString() -> String {
let os = ProcessInfo.processInfo.operatingSystemVersion
let osString = "iOS \(os.majorVersion).\(os.minorVersion).\(os.patchVersion)"
let model = UIDevice.current.model // "iPhone", "iPad"
let machine = {
var sysinfo = utsname()
uname(&sysinfo)
return withUnsafePointer(to: &sysinfo.machine) { ptr -> String in
ptr.withMemoryRebound(to: CChar.self, capacity: 1) { cptr in
String(cString: cptr)
}
}
}() // z.B. "iPhone15,2"
return "Model Identifier: \(model) (\(machine)), \(osString)"
}
I file a bugreport via Feedback Assistant FB22038921
The problem is no around for such a long time ! This is deeply concerning, because it questions if it is really feasable to continue to develop using Spritekit ?
Dear colleagues, when will you add the ability to manually adjust the display's color temperature? Everyone is familiar with the color rendering issue on the 17 series. Many complain about the display's yellowish tint. I'm one of those people, with a G9N panel, but I can't get whites right; there's a persistent yellow tint. TrueTone only solves this problem under cool, white lighting conditions. So, the display might work as intended, but how can I make it work consistently? If there were a way to manually adjust TrueTone, many users wouldn't be so upset when buying a new device, fearing the display would be yellow. I'd like users to be able to choose their preferred color, warm or cool, and have a scale to adjust it! This would solve the yellowish tint issue on 17 series displays! Thank you.
Topic:
Graphics & Games
SubTopic:
General
When building a Unity iOS game, the app name displays incorrectly as "BigBall" on the iPhone home screen, despite setting the project name and bundle identifier to "Big Ball" in Unity and Apple Developer account. The correct name, "Big Ball," appears in TestFlight.
I tried solutions from ChatGPT and DeepSeek, but none were satisfactory.
Please help me.
The sample code just draw a triangle and sample texture.
both sample code can draw a correct triangle and sample texture as expected. there are no error message from terminal.
Sample code using constexpr Sampler can capture and replay well.
Sample code using a argumentTable to bind a MTLSamplerState was crashed when using Metal capture and replay on Xcode.
Here are sample codes.
Sample Code
Test Environment:
M1 Pro
MacOS 26.3 (25D125)
Xcode Version 26.2 (17C52)
Feedback ID: FB22031701
We are seeing crashes in Xcode organizer. So far we are not able to reproduce them locally. They affect multiple app releases (some older, built with Xcode 15.x and newer built with Xcode 16.0). They only affect iOS 18.5.
Is there anything that changed in latest iOS? It's hard to tell what exactly is causing this crash because setting symbolic breakpoint on CA::Render::Image::new_image(unsigned int, unsigned int, unsigned int, unsigned int, CGColorSpace*, void const*, unsigned long const*, void (*)(void const*, void*), void*) triggers this breakpoint all the time, but not necessarily with exactly the previous stack frames matching the crash report.
Is it a known issue?
crash.crash
Thank you.
Hi. I'm a 3D designer, using Blender for most of my work. The most recent Blender conference discussed utilizing the Open Shading Language (OSL) in their latest versions, which allows designers to write custom shaders for their workflows.
At the moment, only Nvidia Optix GPU's can utilize this language for rendering (from what I understand), but Blender developers stated they are waiting on other GPU manufacturers to implement this feature as well. I'm not sure if there are any licensing issues here, but would this be something Apple could implement in Metal to make their hardware more attractive to the 3D design community?
Any help or knowledge on this topic would be greatly appreciated.
Hi,
I’m testing Unity’s Spaceship HDRP demo on iPhone 17 Pro Max and iPad Pro M4 (iOS 26.1).
Everything renders correctly, and my custom MetalFX Spatial plugin initializes successfully — it briefly reports active scaling (e.g. 1434×660 → 2868×1320 at 50% scaling), then reverts to native rendering a few frames later.
Setup:
Xcode 16.1 (targeting iOS 18)
Unity 2022.3.62f3 (HDRP)
Metal backend
Dynamic Resolution enabled in HDRP assets and cameras
Relevant Xcode console excerpt:
[MetalFXPlugin] MetalFX_Enable(True) called.
[SpaceshipOptions] MetalFX enabled with HDRP dynamic resolution integration.
[SpaceshipOptions] Disabled TAA for MetalFX Spatial.
[SpaceshipOptions] Created runtime RenderTexture: 1434x660
[MetalFX] Spatial scaler created (1434x660 → 2868x1320).
[MetalFX] Processed frame with scaler.
[MetalFXPlugin] Sent RenderTexture (1434x660) to MetalFX. Output target 2868x1320.
[SpaceshipOptions] MetalFX target set: 1434x660
[SpaceshipOptions] Camera targetTexture cleared after MetalFX handoff.
It looks like HDRP clears the camera’s target texture right after MetalFX submits the frame, which causes it to revert to native rendering.
Is there a recommended way to persist or rebind the MetalFX output texture when using HDRP on iOS?
Unity doesn’t appear to support MetalFX in the Editor either:
Thanks!
I have run into an issue where I am trying to use atomic_float in a swift package but I cannot get things to compile because it appears that the Swift Package Manager doesn't support Metal 3 (atomic_float is Metal 3 functionality). Is there any way around this? I am using
// swift-tools-version: 6.1
and my Metal code includes:
#include <metal_stdlib>
#include <metal_geometric>
#include <metal_math>
#include <metal_atomic>
using namespace metal;
kernel void test(device atomic_float* imageBuffer [[buffer(1)]],
uint id [[ thread_position_in_grid ]]) {
}
But I get an error on the definition of atomic_float .
Any help, one more importantly, where I could have found this information about this limitation, would be helpful.
-RadBobby
Topic:
Graphics & Games
SubTopic:
Metal
我们想在游戏类 App 内接入 Game Center。用户可以在游戏内创建多个角色,若用户在游戏内创建了2个角色:角色1、角色2,请问:
当用户将角色1与 Game Center 绑定后,数据将上报至 Game Center。此时玩家想要将角色1与 Game Center 解除绑定,解绑后,再将角色2与 Game Center 绑定。那么这时角色1的数据是留存在 Game Center 中,还是将被移除?
How can one match the walls and floor of a given CapturedRoom ?
The transform.eulerAngles of a floor z & y are always 0 !
And the polygons seems to have a different orientation than the walls.
So how to figure out the rotation and match the one from the walls ?