In the SceneKit framework, I want to render a point cloud and need to set the minimumPointScreenSpaceRadius property of the SCNGeometryElement class, but it doesn't work. I searched for related issues on the Internet, but didn't get a final solution. Here is my code: - (SCNGeometry *)createGeometryWithVector3Data:(NSData *)vData colorData: (NSData * _Nullable)cData{ int stride = sizeof(SCNVector3); long count = vData.length / stride; SCNGeometrySource *dataSource = [SCNGeometrySource geometrySourceWithData:vData semantic:SCNGeometrySourceSemanticVertex vectorCount:count floatComponents:YES componentsPerVector:3 bytesPerComponent:sizeof(float) dataOffset:0 dataStride:stride]; SCNGeometryElement *element = [SCNGeometryElement geometryElementWithData:nil primitiveType:SCNGeometryPrimitiveTypePoint primitiveCount:count bytesPerIndex:sizeof(int)]; element.minimumPointScreenSpaceRadius = 1.0; // not work element.maximumPointScreenSpaceRadius = 20.0; SCNGeometry *pointCloudGeometry; SCNGeometrySource *colorSource; if (cData && cData.length != 0) { colorSource = [SCNGeometrySource geometrySourceWithData:cData semantic:SCNGeometrySourceSemanticColor vectorCount:count floatComponents:YES componentsPerVector:3 bytesPerComponent:sizeof(float) dataOffset:0 dataStride:stride]; pointCloudGeometry = [SCNGeometry geometryWithSources:@[dataSource, colorSource] elements:@[element]]; } else { pointCloudGeometry = [SCNGeometry geometryWithSources:@[dataSource] elements:@[element]]; } return pointCloudGeometry; }

Hello there, I'm having trouble matching what I see in the scenekit editor and the output of the resulting scene in a scnview. For a glitter effect I have set a high value on the diffuse intensity which looks fine in the editor but when running the game the colors are much darker. To see if the intensity value is merely capped I have set the same multiplier on the hat below - but it is blown out which looks to me like there is some grading going on I have tried to switch on hdr rendering but that didn't make a difference. I tried disabling linear rendering and that simply made everything darker still - which I expect. Does someone have an idea what else this could be? What rendering is the scenekit editor using and how can I match it? Interestingly when I take a screenshot of the editor window for this post, the image is also blown out... what is going on? :) Thanks so much for any pointers, Seb

I use SCNScene.write To file ".usdz", then open the ".usdz" by SCNScene.url , all Nodes color fades. Export and load only once. The fading is not obvious. Return and repeat 4 or 5 times. It is obvious that the color is inconsistent with the original color and has become much lighter.

Hello, I'm currently working on my first SceneKit game and have encountered an issue related to moving an SCNNode using a UIPanGestureRecognizer. When I deploy the game to my iPhone via Xcode in debug mode, all interactions are smooth. However, when I stop the debugging session and run the game directly from the device (outside of Xcode), the SCNNode movement behaves inconsistently — it works sometimes smoothly and sometimes not and the interaction becomes choppy. The SCNNode movement is controlled using a UIPanGestureRecognizer. Do you have any ideas what might be causing the issue?

Now that SceneKit has been marked as soft deprecated, is there a planned date or timeframe when it will be completely removed from iOS? I’m concerned about how long my existing SceneKit-based game will continue to work, especially as an indie developer without the resources for a quick rewrite to RealityKit.

Hi Friends! I’m facing an issue with SceneKit. I’m developing a 3D mobile game. I have a character 3D model and several skeletal animations CAAnimation. I import both the model and the animations from Maya in *.dae format. The character’s animations play continuously one after the other, with each new animation being triggered randomly. The transition between animations makes smoothly by setting the fadeInDuration and fadeOutDuration properties. Here’s an example of the code: import UIKit import QuartzCore import SceneKit class TestAnimationController: UIViewController { var bodyNode: SCNNode? override func viewDidLoad() { super.viewDidLoad() let scnView = SCNView(frame: self.view.bounds) scnView.backgroundColor = .black // Set your desired background color scnView.autoresizingMask = [.flexibleWidth, .flexibleHeight] let scene = SCNScene(named: "art.scnassets/scene/Base_room/ROOM5.scn")! bodyNode = collada2SCNNode(filepath: "art.scnassets/female/girl_body_races.dae")! bodyNode?.renderingOrder = 10 scene.rootNode.addChildNode(bodyNode!) playIdleAnimation() scnView.scene = scene // Assign the scene to the SCNView self.view.addSubview(scnView) // Add the SCNView to your main view) } func collada2SCNNode(filepath:String) -> SCNNode? { if let scene = SCNScene(named: filepath) { let node = scene.rootNode.childNodes[0] return node } else { return nil } } func playIdleAnimation() { let array = [ "art.scnassets/female/animations/idle/girl_idle_4.dae", "art.scnassets/female/animations/idle/girl_idle1.dae", "art.scnassets/female/animations/idle/girl_idle2.dae", "art.scnassets/female/animations/idle/Girl_idle3.dae", ] let animation = CAAnimation.animationWithSceneNamed(array.randomElement() ?? "")! self.setAnimationAdd( fadeInDuration: 1.0, fadeOutDuration: 1.0, keyTime: 0.99, animation, isLooped: false ) { [weak self] in guard let self = self else { return } try? self.playBoringAnimations() } } func playBoringAnimations() { let array = [ "art.scnassets/female/animations/boring/girl_boring1.dae", "art.scnassets/female/animations/boring/girl_boring2.dae", "art.scnassets/female/animations/boring/girl_boring3.dae", "art.scnassets/female/animations/boring/girl_boring4.dae", "art.scnassets/female/animations/boring/girl_boring5.dae", "art.scnassets/female/animations/boring/girl_boring6.dae", "art.scnassets/female/animations/boring/girl_boring8.dae" ] let animation = CAAnimation.animationWithSceneNamed(array.randomElement() ?? "")! self.setAnimationAdd( fadeInDuration: 1.0, fadeOutDuration: 1.0, keyTime: 0.99, animation, isLooped: false ) { [weak self] in guard let self = self else { return } try? self.playIdleAnimation() } } func setAnimationAdd(fadeInDuration : CGFloat, fadeOutDuration : CGFloat, keyTime : CGFloat, _ animation: CAAnimation, isLooped: Bool, completion: (() -> Void)?) { animation.fadeInDuration = fadeInDuration animation.fadeOutDuration = fadeOutDuration if !isLooped { animation.repeatCount = 1 } else { animation.repeatCount = Float.greatestFiniteMagnitude } animation.animationEvents = [ SCNAnimationEvent(keyTime: keyTime, block: { _, _, _ in completion?() }) ] bodyNode?.addAnimation(animation, forKey: "avatarAnimation") } } Everything worked perfectly until I updated to iOS 18. On a physical device, the animations now transition abruptly without the smooth blending that was present in earlier iOS versions. The switch between them is very noticeable, as if the fadeInDuration and fadeOutDuration parameters are being ignored. However, in the iOS 18 simulator, the animations still transition smoothly as before. Here two example videos - IOS 17.5 and IOS 18 https://youtube.com/shorts/jzoMRF4skAQ - IOS 17,5 smooth https://youtube.com/shorts/VJXrZzO9wl0 - IOS 18 not smooth I try this code in IOS 17.5, everything works fine Does anyone have any ideas on how to fix this issue?

SceneKit SCNScene MacOS 15.1 Xcode 16.0 SceneView(scene: , options:[autoenablesDefaultLighting, allowsCameraContol] there is: .rootNode.cameraNode .rootNode.camera .rootNode.nestedChildNodes each with its own animation when the object is animated and dragged by mouse to change the view point, I can't return the view to the previous view. I have reinstated a clone of the original cameraNode, positions of all childNodes, removed and re-activated all animations... in vain. I have also cloned, removed and replaced .rootNode.camera, in vain. The documentation states the camera is "attached" to an SCNNode but does not say how. I make no declaration to associate .rootNode.cameraNode to .rootNode.camera yet if either is absent there is no scene to view. What am I missing? Thanks

I am writing an app to create 3D objects with curved surfaces such as a metal cabinet knob using SceneKit and Model I/O. I want the surfaces to be smooth so that edges between adjacent polygon faces are not visible. According to the documentation for MDLMesh.addNormals(withAttributeNamed: creaseThreshold:), a positive creaseThreshold value lower than 1.0 will interpolate sharper angles between faces into smooth surfaces. I have not been able to get this to work, and I need help with it. The lines of code where the problem occurs are shown here. let mesh = MDLMesh(scnGeometry: surfaceGeometry) // mesh.addNormals(withAttributeNamed: "MDLVertexAttributeNormal", creaseThreshold: 0.9) surfaceGeometry = SCNGeometry(mdlMesh: mesh) When the code is executed with middle line commented out, the knob object is rendered as shown in the screenshot. When that line is not commented out, mesh is altered and the SCNNode for the knob is created with no errors, but the node is not rendered. The questions I have are: (1) What changes do I need the make to the code so that the node will be rendered with a smooth surface?, and (2) what is the recommended way of smoothing a curved surface so that edges between faces are not visible? The full code for the function and a screenshot of the faceted knob object are attached. ![]("https://developer.apple.com/forums/content/attachment/a17feca7-ed6f-440c-add6-760a1cbf8778" "title=Screenshot cabinet knob with faceted surface.png;width=790;height=568") code-block func cabinetKnob() -> SCNNode { let controlPoints: [(x: Float, y: Float)] = [ (0.728,-0.237), (0.176,-0.06), (0.202,0.475), (0.989,0.842), (-0.066,1.093), (-0.726,0.787) ] let pairs = bsplinePath(controlPoints) var knobProfile = [SCNVector3]() for (x,y) in pairs { knobProfile += [ SCNVector3(x: CGFloat(x), y: CGFloat(y), z: 0)] } let nProfiles = 64 // create knob by rotating knobProfile about y-axis let aIncrement: CGFloat = 2 * CGFloat.pi / CGFloat(nProfiles) // ~6 degrees var angle: CGFloat = 0 var knobVertices = knobProfile.map( { $0 } ) angle = 0 for _ in 1...nProfiles { angle += aIncrement // rotate knobProfile about y-axis knobVertices += knobProfile.map( { $0.rotate(about: .y, by: angle) } ) } let source = SCNGeometrySource(vertices: knobVertices) var indices = [[UInt16]]() var i: UInt16 = 0 var j: UInt16 = UInt16(knobProfile.count) // 1st vertex of next profile for k in 0...nProfiles { var stripIndices = [UInt16]() if k == nProfiles { j = 0 } for _ in 0...knobProfile.count-1 { stripIndices += [i, j] i += 1; j += 1 } indices += [stripIndices] } let elements: [SCNGeometryElement] = indices.map( { SCNGeometryElement(indices: $0, primitiveType: .triangleStrip) } ) var surfaceGeometry = SCNGeometry(sources: [source], elements: elements) let mesh = MDLMesh(scnGeometry: surfaceGeometry) // mesh.addNormals(withAttributeNamed: "MDLVertexAttributeNormal", creaseThreshold: 0.9) surfaceGeometry = SCNGeometry(mdlMesh: mesh) let aluminum = SCNMaterial() aluminum.lightingModel = SCNMaterial.LightingModel.physicallyBased aluminum.diffuse.contents = NSColor(srgbRed: 0.95, green: 0.95, blue: 0.95, alpha: 1.0) aluminum.roughness.contents = 0.2 aluminum.metalness.contents = 0.9 aluminum.isDoubleSided = true surfaceGeometry.materials = [ aluminum ] let node = SCNNode(geometry: surfaceGeometry) return node }

I am using SCNTechnique in combination with ARSCNView. The technique is doing so minor post-processing. I have written several filter variant for this post-processing, but I'm facing an issue when with one of the filters/fragment shaders, SCNTechnique discards my output and just presents the plain camera feed on screen instead. This is clearly visible in the Metal pipeline, using the GPU frame debugger. Let me stress that my setup works for 90% of my filters, but not this one and I want to know why. iOS 18.1, iPhone 13 Mini. Xcode 16.1. Encoder 0 & 1 are injected by the system. Render encoder 2 & 3 correspond to my SCNTechnique's render passes: one to manipulate pixel data (darken it in this case) and another to BLIT it back to the main texture. I know the separate buffer is not strictly for this particular operation, but it shouldn't matter. Note that the issue occurs in encoder 4 (not mine but ARKit's). In Render Encoder 4, scn_postprocess_AR_fragment handle my texture (#0, ending in f980) and another from the camera feed (Texture 2). I know this pass is typically used for grain because that's what it used to do before I disabled grain on ARSCNView (+ the buffer still contains grain paramaters). I have other post-processing filters that work just fine. By what magic is ARKit determining to use Texture 2 instead of my Texture 0? Sure, I could keep digging into the minute differences between my shaders to find out which LoC affects how some ARKit shader down the line operates, but it's awfully opaque so far.

I am working on a SceneKit project where I use a CAShapeLayer as the content for SCNMaterial's diffuse.contents to display a progress bar. Here's my initial code: func setupProgressWithCAShapeLayer() { let progressLayer = createProgressLayer() progressBarPlane?.firstMaterial?.diffuse.contents = progressLayer DispatchQueue.main.async { var progress: CGFloat = 0.0 Timer.scheduledTimer(withTimeInterval: 0.1, repeats: true) { timer in progress += 0.01 if progress > 1.0 { progress = 0.0 } progressLayer.strokeEnd = progress // Update progress } } } // MARK: - ARSCNViewDelegate func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) { progressBarPlane = SCNPlane(width: 0.2, height: 0.2) setupProgressWithCAShapeLayer() let planeNode = SCNNode(geometry: progressBarPlane) planeNode.position = SCNVector3(x: 0, y: 0.2, z: 0) node.addChildNode(planeNode) } This works fine, and the progress bar updates smoothly. However, when I change the code to use a class property (self.progressLayer) instead of a local variable, the rendering starts flickering on the screen: func setupProgressWithCAShapeLayer() { self.progressLayer = createProgressLayer() progressBarPlane?.firstMaterial?.diffuse.contents = progressLayer DispatchQueue.main.async { [weak self] in var progress: CGFloat = 0.0 Timer.scheduledTimer(withTimeInterval: 0.1, repeats: true) { [weak self] timer in progress += 0.01 if progress > 1.0 { progress = 0.0 } self?.progressLayer?.strokeEnd = progress // Update progress } } } After this change, the progressBarPlane in SceneKit starts flickering while being rendered on the screen. My Question: Why does switching from a local variable (progressLayer) to a class property (self.progressLayer) cause the flickering issue in SceneKit rendering?

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 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.

Up to now I have created multiple new SCNNodes using an instance of SCNGeometry and it was OK that they all had the same appearance. Now I want variety and when I make a copy of that instance using: let newGeo = myGeoInstance.copy() as! SCNGeometry (must be force cast because copy() -> any?) all elements are verified present. :-) Likewise: node.geometry?.replaceMaterial(at: index, with: myNewMaterial) is verified to correctly change the material(s) at the correct index(s). The only problem is the modified "teapot" is not visible, and yes I have set node.isHidden = false. Has anyone experienced this? In the old days reversing the verts was a solution. In desperation I tried that. |-(

Hi Looking at the documentation for screenSpaceAmbientOcclusionIntensity, I noticed that it says this is supported on visionOS 1.0+: https://developer.apple.com/documentation/scenekit/scncamera/screenspaceambientocclusionintensity Could someone enlighten me as to how that would work? As far as I know, we don't use an SCNCamera on visionOS. So, what's the idea here? Can we activate SSAO on visionOS?

I've been working on Swift game which is not yet launched or available for preview. The game works in such a way that it has idle CPU while the user is thinking and sustained max CPU and GPU on as many cores as possible when he makes a move. Rarely, due to OS activity or something else outside of my control (for example when dropping the OS curtain even if for just a bit then remove it), the game or some of its threads are moved to efficiency cores which results in major stuttering which persists precisely until the game is idle again at which point the game is moved back on performance cores - but if the player keeps making moves the stuttering simply won't go away and so I guess compuptation is locked onto efficiency cores. The issue does not reproduce on MacCatalyst on Intel. How do I tell Swift to avoid efficiency cores? BTW Swift and SceneKIT have AMAZING performance especially when compared to others.

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!

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 ?