SpriteKit

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Drawing shapes, particles, text, images, and video in two dimensions using SpriteKit.

SpriteKit Documentation

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SKNode.zPosition causes nodes to flicker by reordering them for 1 frame
When running the sample code below, every 3 seconds the middle sprite is replaced by a new one. When this happens, most of the time a flicker is noticeable. When recording the screen and stepping through the recording frame by frame, I noticed that the flicker is caused by a temporary reordering of the nodes’. Below you find two screenshots of two consecutive frames where the reordering is clearly visible. This only happens for a SpriteKit scene used as an overlay for a SceneKit scene. Commenting out buttons.zPosition = 1 or avoiding the fade in/out animations solves the issue. I have created FB15945016. import SceneKit import SpriteKit class GameViewController: NSViewController { let overlay = SKScene() var buttons: SKNode! var previousButton: SKSpriteNode! var nextButton: SKSpriteNode! var pageContainer: SKNode! var pageViews = [SKNode]() var page = 0 override func viewDidLoad() { super.viewDidLoad() let scene = SCNScene(named: "art.scnassets/ship.scn")! let scnView = self.view as! SCNView scnView.scene = scene overlay.anchorPoint = CGPoint(x: 0.5, y: 0.5) scnView.overlaySKScene = overlay buttons = SKNode() buttons.zPosition = 1 overlay.addChild(buttons) previousButton = SKSpriteNode(systemImage: "arrow.uturn.backward.circle") previousButton.position = CGPoint(x: -100, y: 0) buttons.addChild(previousButton) nextButton = SKSpriteNode(systemImage: "arrow.uturn.forward.circle") nextButton.position = CGPoint(x: 100, y: 0) buttons.addChild(nextButton) pageContainer = SKNode() pageViews = [SKSpriteNode(systemImage: "square.and.arrow.up"), SKSpriteNode(systemImage: "eraser")] overlay.addChild(pageContainer) setPage(0) Timer.scheduledTimer(withTimeInterval: 3, repeats: true) { [self] _ in setPage((page + 1) % 2) } } func setPage(_ page: Int) { pageViews[self.page].run(.sequence([ .fadeOut(withDuration: 0.2), .removeFromParent() ]), withKey: "fade") self.page = page let pageView = pageViews[page] pageView.alpha = 0 pageView.run(.fadeIn(withDuration: 0.2), withKey: "fade") pageContainer.addChild(pageView) } override func viewDidLayout() { overlay.size = view.frame.size } } extension SKSpriteNode { public convenience init(systemImage: String) { self.init() let width = 100.0 let image = NSImage(systemSymbolName: systemImage, accessibilityDescription: nil)!.withSymbolConfiguration(.init(hierarchicalColor: NSColor.black))! let scale = NSScreen.main!.backingScaleFactor image.size = CGSize(width: width * scale, height: width / image.size.width * image.size.height * scale) texture = SKTexture(image: image) size = CGSize(width: width, height: width / image.size.width * image.size.height) } }
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Nov ’24
Why is SKPhysicsBody not picking up alpha?! SpriteKit for a WatchOS game.
So I'm trying to use SpriteKit to make the background of my game. The walls have alpha 1.0, and the safe area alpha 0 and fully transparent. (e.g. a big black square with a smaller transparent square in the middle of it). Yet sprite kit always assume the entire image is either fully opaque or fully transparent. That defies its purpose isn't it? Is there a way to make this work?
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Jan ’25
GKObstacleGraph<GKGraphNode2D> copy() not work (Bad ACCESS) (SpriteKit)
Given a graph with added obstacles I want to make a copy of it. When I make the copy: currentGrath added 20 obstacles. var newGrapth = currentGrath.copy() as? GKObstacleGraph newGrapth2.removeObstacles([newGrapth!.obstacles.first!]) This returns a BAD ACCESS. I don't understand what's going on or what the problem is. If I do this same thing with the main network there is no problem: currentGrath.removeObstacles([currentGrath!.obstacles.first!]) Thanks for the help
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Feb ’25
SCNNode into SKScene is deformed when hit an object
Into a SKScene, I add a SCNSphere as a child of SKShapeNode, as depicted below. When the sphere hit another node (the fence in the example) the sphere is deformed as it were elastic. I didn't found any information about elastic properties. Someone know a way to avoid the deformation? import SwiftUI import SpriteKit import SceneKit @main struct MyApp: App { var body: some Scene { WindowGroup {SpriteView(scene: GameSceneSK(size: UIScreen.main.bounds.size))} } } class GameSceneSK: SKScene { override func sceneDidLoad() { var fencePoints = [ CGPoint(x: 300, y: 0), CGPoint(x: 300, y: 400), CGPoint(x: 0, y: 400) ] let fence = SKShapeNode(points: &fencePoints, count: fencePoints.count) fence.physicsBody = SKPhysicsBody(edgeChainFrom: fence.path!) addChild(fence) let sphereGeometry = SCNSphere(radius: 20) let sphereNode = SCNNode(geometry: sphereGeometry) let sphereScnScene = SCNScene() sphereScnScene.rootNode.addChildNode(sphereNode) let ball3D = SK3DNode(viewportSize: CGSize(width: 40, height: 40)) ball3D.scnScene = sphereScnScene let ball = SKShapeNode(circleOfRadius: 20) ball.physicsBody = SKPhysicsBody(circleOfRadius: 20) ball.addChild(ball3D) physicsWorld.gravity = CGVector(dx: 0.2, dy: 0.2) addChild(ball) } }
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Nov ’24
[tvOS] Reacting to button taps
I've just started working on my first SpriteKit game that will eventually run on both tvOS and iOS and am looking at how to build a "button". So far, I've got a custom node that looks like: class MyButton: SKSpriteNode { ... #if os(tvOS) override var canBecomeFocused: Bool { true } override func didUpdateFocus(...) { ... } #endif } The above let me nicely handle focus changes in tvOS and now I'm looking at reacting to selecting the button. Searching around, all the articles/questions/posts are from 2015-2016 - which is a LOOOONG time ago. Most of the guidance appears to be to add a tap gesture recognizer in the owning scene and getting the scene to hand it off to the button. That seems pretty brittle and I'd much prefer if the button itself is responsible for its own tap management. So, I guess my question is whether I should just add a gesture recognizer to my custom button class? Is this inefficient if I end up having 7-8 buttons on the screen and each one has its own gesture recognizer? Somewhat related, all of the 10-year-old advice is that if we add recognizers to scenes, then they need to be removed from the view controller... however, in the modern day world with SwiftUI, my project doesn't even have a view controller (yet, anyway)... what gesture recognizer lifecycle management do I need in a SpriteKit scene that is presented within a SpriteKitView? Or, is there a better way? I was kind of hoping that overriding pressesBegan() (or something similar) in my custom button might have been triggered on tvOS (like touchesBegan() lets me manage touches for the iOS variant of my app) Any pointers or suggestions would be gladly received. Thanks.
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Jan ’25
Unknown CHHapticError.Code (1852797029 == 'nope') in iOS 18+ on iPhone 11 Pro
Hello, I'm getting this error when launching a SpriteKit Swift game in iOS 18+ on an iPhone 11 Pro, whose shell is partly damaged in the back: CHHapticEngine.mm:1206 -[CHHapticEngine doStartWithCompletionHandler:]_block_invoke: ERROR: Player start failed: The operation couldn’t be completed. (com.apple.CoreHaptics error 1852797029.) Haptics do not work on this device, due to the damaged shell, so some error — which obviously occurs when calling start(completionHandler:) — is definitely expected; what is not expected is the main thread sometimes blocking for up to 5 seconds — although the method is not called from the main thread... the error itself is always displayed from some other secondary (system) thread. During this time, the main thread does not access the haptics engine at all; on average, it blocks once every four or five launches. In each launch (blocking or not), the 'nope' error is displayed ~5 seconds after trying to start the engine. After going nuts with all kinds of breakpoints and instrumentation, I'm at a loss as to why the main thread would sometimes block... Ideas, anyone? Thank you, D.
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Jul ’25
SpriteKit: SKTileMap leaks with `SKTexture(rect: CGRect)` usage
Hello reader, I am facing an issue that I am not able to resolve. I have been able to create a demo project that demonstrates the issue, which I hope enables you to have a look as well and hopefully find a way to resolve it. What is the issue: I am using SKTileMapNode in order to draw tile maps. Instead of using the tilesets as you can use from within the Xcode editor, I prefer to do it all programmatically using tilesheets (for a plethora of reasons that I will leave out of this equation). This is the code of the gameScene: import SpriteKit import GameplayKit class GameScene: SKScene { private let tileSize = CGSize(width: 32, height: 32) override func didMove(to view: SKView) { super.didMove(to: view) let tileSet = createTileSet() let tileMap = SKTileMapNode(tileSet: tileSet, columns: 100, rows: 100, tileSize: tileSize) for column in 0..<tileMap.numberOfColumns { for row in 0..<tileMap.numberOfRows { guard let tileGroup = tileSet.tileGroups.randomElement() else { fatalError() } tileMap.setTileGroup(tileGroup, forColumn: column, row: row) } } addChild(tileMap) } private func createTileSet() -> SKTileSet { let tileSheetTexture = SKTexture(imageNamed: "terrain") var tileGroups = [SKTileGroup]() let relativeTileSize = CGSize(width: tileSize.width/tileSheetTexture.size().width, height: tileSize.height/tileSheetTexture.size().height) for idx in 0...2 { for jdx in 0...2 { let tileTexture = SKTexture(rect: .init(x: CGFloat(idx) * relativeTileSize.width, y: CGFloat(jdx) * relativeTileSize.height, width: relativeTileSize.width, height: relativeTileSize.height), in: tileSheetTexture) let tileDefinition = SKTileDefinition(texture: tileTexture, size: tileSize) let tileGroup = SKTileGroup(tileDefinition: tileDefinition) tileGroups.append(tileGroup) } } let tileSet = SKTileSet(tileGroups: tileGroups) return tileSet } override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) { presentSceneAgain() } func presentSceneAgain() { if let frame = view?.frame { view?.presentScene(GameScene(size: frame.size), transition: .doorsCloseHorizontal(withDuration: 1.0)) } } } This demo project create a tilemapnode of 100 X 100 tiles. Then, it fills these 10.000 tiles with a random tile from the tilesheet named "terrain.png". This tile sheet contains many tiles, but I only take the 9 tiles (3 X 3) from the lower left corner as a random tile option. Thus, the 10.000 tiles get filled with one of these 9 tiles. So it doesnt look pretty or anything, but that isnt the purpose. Now, to create these 9 tile textures, I use the SKTexture(rectIn:) method on the source texture being "terrain.png". I think the code is quite clear in itself, but so far the explanation. When you run it, you should see the map being rendered. When you tap the scene, the scene will present a new instance of the scene. Not more than that. Now, when you do this, have a look at the RAM usage of the app. You will see it steadily increases over time, each time you click the scene and a new scene is presented. I looked deeper into what is happening, and what I see in the memory graph, is that for every present of the scene that is done, there are 3 SKTexture instances being created that are never released. The first time the scene is rendered, there 11 SKTexture instances allocated (I dont know why there are 11 though. I would expect 10: the source texture and the 9 tile textures). But then as mentioned, after a tap and a new present, I get 14 SKTexture, of which 3 are zombies, see image leak_1. Moreover, Xcode reports multiple additional leaks from Jet and Metal allocations, see image leak_all. As far as I know, the code presented is not retaining any references that it should not, and I suspect this leaks are happening somewhere inside SpriteKit. But I am not able to find exactly where, or how to resolve it. I hope someone can help with this issue.
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Nov ’24
SpriteKit framerate drop on iOS 26.0
Hello, I have noticed a performance drop on SpriteKit-based projects running on iOS 26.0 (23A341). Below is a SpriteKit scene used to test framerate on different devices: import SpriteKit import SwiftUI class BareboneScene: SKScene { override func didMove(to view: SKView) { size = view.bounds.size anchorPoint = CGPoint(x: 0.5, y: 0.5) backgroundColor = .darkGray let roundedSquare = SKShapeNode(rectOf: CGSize(width: 150, height: 75), cornerRadius: 12) roundedSquare.fillColor = .systemRed roundedSquare.strokeColor = .black roundedSquare.lineWidth = 3 addChild(roundedSquare) let action = SKAction.rotate(byAngle: .pi, duration: 1) roundedSquare.run(.repeatForever(action)) } } struct BareboneSceneView: View { var body: some View { SpriteView( scene: BareboneScene(), debugOptions: [.showsFPS] ) .ignoresSafeArea() } } #Preview { BareboneSceneView() } The scene is very simple, yet framerate drops to ~40 fps as shown by the Metal HUD. Tested on: iPhone 13, iOS 26.0: framerate drops to 40 fps. Sometimes it runs at near 60fps. But if the screen is touched repeatedly, the framerate drops to 40-50 fps again. iPhone 11 Pro, iOS 26.0: ~40fps. iPad 9th Gen, iOS 18.6.2: 60fps, no issues. See screenshots attached. These numbers were observed by me and members of our beloved SpriteKit Discord server. Thank you for your attention.
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virtual game controller + SwiftUI warning
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 } }
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Sep ’25
playSoundFileNamed not working on Tahoe?
I have published a number of games that use SpriteKit for everything important. Since the release of macOS Tahoe, I've had a lot of end user reports saying that sound effects have stopped working in many (but not all) of my titles. I'm not doing anything unusual here – typical code is: sndGameOver = [SKAction playSoundFileNamed:@"Audio/GameOver.wav" waitForCompletion:YES]; Then at the appropriate time: [self runAction:sndGameOver]; Has anyone else encountered this? The code still works fine on previous operating systems, and appears to be fine on iOS too. Has something changed in macOS Tahoe? I'm at a bit of a loss. There's nothing obviously different between the titles that do work and the titles that don't. Suggestions welcomed! Thanks
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Image textures cause runtime crashes - what's the workaround?
I've had no issue calling image files in my .swift files, but they are causing crashes when used in my .SKS files. When I set a sprite texture to an image in the inspector/ editor bar, at runtime when that sprite is being called I get the error: "Cannot get value with size 16. The type encoded as {CGRect={CGPoint=dd}{CGSize=dd}} is expected to be 32 bytes." From my research it has something to do with Apple switching from 32 to 64 bite machines. From chatGPT “SpriteKit under the hood uses NSKeyedUnarchiver to load your .sks file. That unarchiver decodes each archived property by reading a fixed‑size blob of bytes and mapping it into a C struct. In your case it ran into a mismatch”. I am using a 64-bite machine to write my code and 64-bite simulators and physical devices, so there isn't a clear cause of the mismatch. My scenes play fine in Xcode 16's preview window and my code builds, it just crashes at runtime. When I don’t use image textured assets in the SKS file it works fine. It loads animated labels, and plain color squares. I’ve been able to work around this for static things like a sprite with a background texture by. in a normal non-game swift file, writing code like: if let scene = SKScene(fileNamed: "GameScene2") { let bg = SKSpriteNode(imageNamed: "YourBackgroundImage") bg.position = CGPoint(x: scene.frame.midX, y: scene.frame.midY) bg.zPosition = -1 scene.addChild(bg) } The issue now is I want to make a particle emitter and other non static sprites, but my understanding of their properities isn’t deep enough to create them without the editor. Also when I set SKTexture in a swift file that causes the same runtime crash with the 16/32 error. Could you help me figure out how to fix the bug so I can use the editor again? Otherwise could you help me figure out how to write a workaround like I do for background images? I have a feeling the answer is in writing my own NSKeyedUnarchiver but I don’t know how to make sure it’s called instead of the default one. I've already tried cleaning my code multiple times and deleting and reading sprite nodes. Thank you.
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