I've been running my SceneKit game for many weeks in Xcode without performance issues. The game itself is finished, so I thought I could go on with publishing it on the App Store, but when archiving it in Xcode and running the archived app, I noticed that it seriously hangs. The hangs only seem to happen when I run the game in fullscreen mode. I tried disabling game mode, but the hangs still happen. Only when I run in windowed mode the game runs smoothly. Instruments confirms that there are many serious hangs, but it also reports that CPU usage is quite low during those hangs, on average about 15%. From what I know, hangs happen when the main thread is busy, but how can that be when CPU usage is so low, and why does it only happen in fullscreen mode for release builds?

The Actions Editor doesn't seem to work in Xcode 16.1. With a node selected, when I try to drag an action from the Library into the Actions panel nothing happens, the action icon just disappears. Clicking the '+' button to create a new action doesn't work either. Actions do work when created in code, though. Is this a bug, or am I missing something?

I would like to implement zoom functionality in my SceneKit game: when the user performs the pinch gesture on a point on the screen, the scene zooms in to make that point larger. Until now I simply changed SCNCamera.focalLength, but this simply zooms in to the center of what is currently visible on screen. Is it somehow possible to implement the zoom functionality described above by perhaps interactively rotating the camera at the same time towards the pinched point? Is there a formula for this? I would like to avoid suddenly rotating the camera to face the pinched point when the pinch gesture begins and then zoom in while the pinch is in progress.

I am trying to extract some built-in and custom render passes from SceneKit, so that I can pass them into a metal pipeline and do some additional work with them. I have a metal viewport, and have instantiated a SCNRenderer so that I can render a SCNScene using SceneKit to a texture as part of my metal draw pass. This works as expected. Now I want to output multiple textures from the SceneKit render, not just the final color. I want to extract Depth, Normal, Lighting, Colour and a custom SCNTechnique for world position. I can easily use a SCNTechnique to render one of these to the color output, but it's not clear how I would render multiple passes in one render call. Is there some way to pass a writeable buffer/texture to a SCNTechnique, so that I can populate it in my SCNTechnique shader at render time with the output from the pass? Similar to how one would bind a buffer for a metal shader. SCNTechnique obfuscates things, so it's not clear how to proceed. Does anyone have any ideas?

I am trying to port SceneKit projects to Swift 6, and I just can't figure out how that's possible. I even start thinking SceneKit and Swift 6 concurrency just don't match together, and SceneKit projects should - hopefully for the time being only - stick to Swift 5. The SCNSceneRendererDelegate methods are called in the SceneKit Thread. If the delegate is a ViewController: class GameViewController: UIViewController { let aNode = SCNNode() func renderer(_ renderer: any SCNSceneRenderer, updateAtTime time: TimeInterval) { aNode.position.x = 10 } } Then the compiler generates the error "Main actor-isolated instance method 'renderer(_:updateAtTime:)' cannot be used to satisfy nonisolated protocol requirement" Which is fully understandable. The compiler even tells you those methods can't be used for protocol conformance, unless: Conformance is declare as @preconcurrency SCNSceneRendererDelegate like this: class GameViewController: UIViewController, @preconcurrency SCNSceneRendererDelegate { But that just delays the check to runtime, and therefore, crash in the SceneKit Thread happens at runtime... Again, fully understandable. or the delegate method is declared nonisolated like this: nonisolated func renderer(_ renderer: any SCNSceneRenderer, updateAtTime time: TimeInterval) { aNode.position.x = 10 } Which generates the compiler error: "Main actor-isolated property 'position' can not be mutated from a nonisolated context". Again fully understandable. If the delegate is not a ViewController but a nonisolated class, we also have the problem that SCNNode can't be used. Nearly 100% of the SCNSceneRendererDelegate I've seen do use SCNNode or similar MainActor bound types, because they are meant for that. So, where am I wrong ? What is the solution to use SceneKit SCNSceneRendererDelegate methods with full Swift 6 compilation ? Is that even possible for now ?