Hi, I'm trying to understand how I can get 3- or 4-channel per-vertex data into the Graph Editor. From my tests, it seems that: the "Geometric Property" node does not give access to 4-channel data, "Geometric Property (vector3)" does not give me access to custom properties besides the ones defined in MaterialX core the "Texture Coordinates" node has a vector4f mode (yay!), but according to MaterialX spec, texcoords must have 2 or 3 channels, and I can't get 4-channel data to show up there either. My assumption so far is that I must be missing some "magic" – for example, do the primvars in a file have to be in a specific order, independent of their names? Or do their names matter? (E.g. convention would be primars:st and primvars:st1 and so on) Unfortunately the forum doesn't allow me to attach any USDZ or ZIP files or GDrive links; if there's a way to share a test file I'm happy to do so!

I'm using RealityKit for a scene with many static and dynamic ModelEntitys simulating physics. When all the entities have simple collision generated from .generateCollisionShapes I don't see any issues, but for some entities I need much more complex and accurate collision. For this I've been using ShapeResource.generateStaticMesh with the mesh's data (2769 positions, 16272 face indices in this case), which works exactly as desired with a low entity count. However once there are 600+ dynamic entities introducing even one static entity with complex collision will reliably trigger a crash when colliding with one of the dynamic entities (not necessarily on first contact, but inevitably after multiple collisions). If I arbitrarily limit the number of entities to a max of around 500 it seems to prevent the issue from happening, though the likelihood seems to increase with the number of entities so there may be a low probability of it triggering even at 500 entities that I haven't hit while testing. If physx imposes some kind of entity or collision face/shape limit or something like that I'd at least like to know exactly what it is, but ideally there's a way to work around this. Right now my "fix" is just arbitrarily restricting the entity count in a way that limits what my app can do. The crash triggers inside 0x00000001a6790dfc in physx::PxcDiscreteNarrowPhasePCM(physx::PxcNpThreadContext&, physx::PxcNpWorkUnit const&, physx::Gu::Cache&, physx::PxsContactManagerOutput&) () which looks like this (crash line has an -> arrow at the bottom) CoreRE`physx::PxcDiscreteNarrowPhasePCM: ... 0x1a6790df0 <+668>: mov x1, x24 0x1a6790df4 <+672>: bl 0x1a67913d8 ; physx::PxcNpCacheStreamPair::reserve(unsigned int) 0x1a6790df8 <+676>: ldrb w8, [x23] -> 0x1a6790dfc <+680>: str w8, [x0, #0x20]

Summary: I’m working on a VisionOS project where I need to dynamically load a .bundle file containing RealityKit content from the app’s Application Support directory. The .bundle is saved to disk after being downloaded or retrieved as an On-Demand Resource (ODR). Sample project with the issue: Github repo. Play the target test-odr to use with the local bundle and have the crash. Overall problem: Setup: Add a .bundle named RealityKitContent_RealityKitContent.bundle to the app’s resources. This bundle contains a Reality file with two USDA,: “Immersive” and “Scene”. Save to Disk: save the bundle to the Application Support directory, ensuring that the file is correctly copied and saved. Load the Bundle: load the bundle from the saved URL using Bundle(url: bundleURL) to initialize the Bundle object. Load Entity from Bundle: load a specific entity (“Scene”) from the bundle. When trying to load the entity using let storedEntity = try await Entity(named: "Scene", in: bundle), the app crashes with an EXC_BREAKPOINT error. ContentsOf Method Issue: If I use the Entity.load(contentsOf:realityFileURL, withName: entityName) method, it always loads the first root entity found (in this case, “Immersive”) rather than “Scene”, even when specifying the entity name. This is why I want to use the Bundle to load entities by name more precisely. Issue: The crash consistently occurs on the Entity(named: "Scene", in: bundle) line. I have verified that the bundle exists and is accessible at the specified path and that it contains the expected .reality file with multiple entities (“Immersive” and “Scene”). The error code I get is EXC_BREAKPOINT (code=1, subcode=0x1d135d4d0). What I’ve Tried: • Ensured the bundle is properly saved and accessible. • Checked that the bundle is initialized correctly from the URL. • Tested loading the entity using the contentsOf method, which works fine but always loads the “Immersive” entity, ignoring the specified name. Hence, I want to use the Bundle-based approach to load multiple USDA entities selectively. Question: Has anyone faced a similar issue or knows why loading entities using Entity(named:in:) from a disk-based bundle causes this crash? Any advice on how to debug or resolve this, especially for managing multiple root entities in a .reality file, would be greatly appreciated.

I am having a difficult time to create particle systems in Reality Composer Pro (visionOS beta 3). They tend to start to flicker and all particles disappear and reappear in semi-random intervals. I can clearly see that happening with one effect that I put inside a small box consisting of 4 transparent walls that has a solid floor. When I change the view angle the particle system starts to flicker when viewed from below its emission height. I tried all combinations of particle rendering: billboard->free, additive etc and it does not change anything. I am using the default particle image. Any help appreciated

I'm trying to ray-march an SDF inside a RealityKit surface shader. For the SDF primitive to correctly render with other primitives, the depth of the fragment needs to be set according to the ray-surface intersection point. Is there a way to do that within a RealityKit surface shader? It seems the only values I can set are within surface::surface_properties. If not, can an SDF still be rendered in RealityKit using ray-marching?

In my Metal-based app, I ray-march a 3D texture. I'd like to use RealityKit instead of my own code. I see there is a LowLevelTexture (beta) where I could specify a 3D texture. However on the Metal side, there doesn't seem to be any way to access a 3D texture (realitykit::texture::textures::custom returns a texture2d). Any work-arounds? Could I even do something icky like cast the texture2d to a texture3d in MSL? (is that even possible?) Could I encode the 3d texture into an argument buffer and get that in somehow?

UI: Attachment(id: "tooptip") { if isRecording { TooltipView { HStack(spacing: 8) { Image(systemName: "waveform") .font(.title) .frame(minWidth: 100) } } .transition(.opacity.combined(with: .scale)) } } Trigger: Button("Toggle") { withAnimation{ isRecording.toggle() } } The above code did not show the animation effect when running. When I use isRecording to drive an element in a common SwiftUI view, there is an animation effect.

Hi, I'm trying to capture some images from WKWebView on visionOS. I know that there's a function 'takeSnapshot()' that can get the image from the web page. But I wonder if 'drawHierarchy()' cannot work properly on WKWebView because of GPU content, is there any other methods I can call to capture images correctly? Furthermore, as I put my webview into an immersive space, is there any way I can get the texture of this UIView attachment? Thank you

Context being VisionOS development, I was trying to do something like let root = ModelEntity() child1 = ModelEntity(...) root.addChild(child1) child2 = ModelEntity(...) root.addChild(child2) only to find that, despite seemingly being together, I can only pick by children entities when I apply a DragGesture in VisionOS. Any idea what's going on?

I have a RealityView in my visionOS app. I can't figure out how to access RealityRenderer. According to the documentation (https://developer.apple.com/documentation/realitykit/realityrenderer) it is available on visionOS, but I can't figure out how to access it for my RealityView. It is probably something obvious, but after reading through the documentation for RealityView, Entities, and Components, I can't find it.

If you create a custom shader you get access to a collection of uniform values, one is the uniforms::time() parameter which is defined as "the number of seconds that have elapsed since RealityKit began rendering the current scene" in this doc: https://developer.apple.com/metal/Metal-RealityKit-APIs.pdf Is there some way to get this value from Swift code? I want to animate a value in my shader based on the time so I need to get the starting time value so I can interpolate the animation offset from that point. If I create a System in the update() function I get a SceneUpdateContext instance and that has a deltaTime property but not an elapsedTime property which I would assume would map to the shader time() value.

Is it possible with iOS 18 to use RealityView with world tracking but without the camera feed as background? With content.camera = .worldTracking the background is always the camera feed, and with content.camera = .virtual the device's position and orientation don't affect the view point. Is there a way to make a mixture of both? My use case is that my app "Encyclopedia GalacticAR" shows astronomical objects and a skybox (a huge sphere), like a VR view of planets, as you can see in the left image. Now that iOS 18 offers RealityView for iOS and iPadOS, I would like to make use of it, but I haven't found a way to display my skybox as environment, instead of the camera feed. I filed the suggestion FB14734105 but hope that somebody knows a workaround...

Hello Guys, I'm looking for how to look at the 3D object around me, pinch it (from far with eyes and 2 fingers, not touch them) and display a little information on top of it (like little text). If you have the solution you will make me happy (and a bit less stupid too :) ) Cheers Mathis

Starting with Xcode Beta 4+, any ModelEntity I load from usdz that contain a skeletal pose has no pins. The pins used to be accessible from a ModelEntity so you could use alignment with other pins. Per the documentation, any ModelEntity with a skeletal pose should have pins that are automatically generated and contained on the entity.pins object itself. https://developer.apple.com/documentation/RealityKit/Entity/pins Is this a bug with the later Xcode betas or is the documentation wrong?

I'm trying to clone an entity that's somewhere deeper in hierarchy and I want it together with transform that takes into account parents. Initially I made something that would go back through parents, get their transforms and then reduce them to single one. Then I realized that what I'm doing is same as .transformMatrix(relativeTo: rootEntity), but to validate that what I made gives same results I started to print them both and I noticed that for some reason the last row instead of stable (0,0,0,1) is sometimes (0,0,0,0.9999...). I know that there are rounding errors, but I'd assume that 0 and 1 are "magical" in FP world. The only way I can try to explain it, is that .transformMatrix is using some fancy accelerated matrix multiplication and those produce some bigger rounding errors. That would explain slight differences in other fields between my version and function call, but still - the 1 seems weird. Here's function I'm using to compare: func cloneFlattened(entity: Entity, withChildren recursive: Bool) -> Entity { let clone = entity.clone(recursive: recursive) var transforms = [entity.transform.matrix] var parent: Entity? = entity.parent var rootEntity: Entity = entity while parent != nil { rootEntity = parent! transforms.append(parent!.transform.matrix) parent = parent!.parent } if transforms.count > 1 { clone.transform.matrix = transforms.reversed().reduce(simd_diagonal_matrix(simd_float4(repeating: 1)), *) print("QWE CLONE FLATTENED: \(clone.transform.matrix)") print("QWE CLONE RELATIVE : \(entity.transformMatrix(relativeTo: rootEntity))") } else { print("QWE CLONE SINGLE : \(clone.transform.matrix)") } return clone } Sometimes last one is not 1 QWE CLONE FLATTENED: [ [0.00042261832, 0.0009063079, 0.0, 0.0], [-0.0009063079, 0.00042261832, 0.0, 0.0], [0.0, 0.0, 0.0010000002, 0.0], [-0.0013045187, -0.009559666, -0.04027118, 1.0] ] QWE CLONE RELATIVE : [ [0.00042261826, 0.0009063076, -4.681872e-12, 0.0], [-0.0009063076, 0.00042261826, 3.580335e-12, 0.0], [3.4256328e-12, 1.8047965e-13, 0.0009999998, 0.0], [-0.0013045263, -0.009559661, -0.040271178, 0.9999997] ] Sometimes it is QWE CLONE FLATTENED: [ [0.0009980977, -6.1623556e-05, -1.7382005e-06, 0.0], [-6.136851e-05, -0.0009958588, 6.707259e-05, 0.0], [-5.8642554e-06, -6.683835e-05, -0.0009977464, 0.0], [-1.761913e-06, -0.002, 0.0, 1.0] ] QWE CLONE RELATIVE : [ [0.0009980979, -6.1623556e-05, -1.7382023e-06, 0.0], [-6.136855e-05, -0.0009958589, 6.707254e-05, 0.0], [-5.864262e-06, -6.6838256e-05, -0.0009977465, 0.0], [-1.758337e-06, -0.0019999966, -3.7252903e-09, 1.0] ] 0s in last row seem to be stable. It happens both for entities that are few levels deep and those that have only anchor as parent. So far I've never seen any value that would not be "technically a 1", but my hierarchies are not very deep and it makes me wonder if this rounding could get worse. Or is it just me doing something stupid? :)

I'm trying to load up a virtual skybox, different from the built-in default, for a simple macOS rendering of RealityKit content. I was following the detail at https://developer.apple.com/documentation/realitykit/environmentresource, and created a folder called "light.skybox" with a single file in it ("prairie.hdr"), and then I'm trying to load that and set it as the environment on the arView when it's created: let ar = ARView(frame: .zero) do { let resource = try EnvironmentResource.load(named: "prairie") ar.environment.lighting.resource = resource } catch { print("Unable to load resource: \(error)") } The loading always fails when I launch the sample app, reporting "Unable to load resource ..." and when I look in the App bundle, the resource that's included there as Contents/Resources/light.realityenv is an entirely different size - appearing to be the default lighting. I've tried making the folder "light.skybox" explicitly target the app bundle for inclusion, but I don't see it get embedded with it toggle that way, or just default. Is there anything I need to do to get Xcode to process and include the lighting I'm providing? (This is inspired from https://stackoverflow.com/questions/77332150/realitykit-how-to-disable-default-lighting-in-nonar-arview, which shows an example for UIKit)

Hello, I’m playing around with making an fully immersive multiplayer, air to air dogfighting game, but I’m having trouble figuring out how to attach a camera to an entity. I have a plane that’s controlled with a GamePad. And I want the camera’s position to be pinned to that entity as it moves about space, while maintaining the users ability to look around. Is this possible? -- From my understanding, the current state of SceneKit, ARKit, and RealityKit is a bit confusing with what can and can not be done. SceneKit Full control of the camera Not sure if it can use RealityKits ECS system. 2D Window. - Missing full immersion. ARKit Full control of the camera* - but only for non Vision Pro devices. Since Vision OS doesn't have a ARView. Has RealityKits ECS system 2D Window. - Missing full immersion. RealityKit Camera is pinned to the device's position and orientation Has RealityKits ECS system Allows full immersion

Hey everyone, I'm working on an iOS app where I use AVPlayer to play videos, then process them through Metal to apply effects. The app has controls that let users tweak these effects in real-time, and I want the final processed video to be streamed via AirPlay. I use a custom rendering layer that uses a Metal texture to display the processed video on the screen an that works as intended. The problem is, when I try to AirPlay the video after feeding it the processed metal frames, it’s just streaming the original video from AVPlayer, not the version with all the Metal effects. The final processed output is a Metal texture that gets rendered in a MTKView. I even tried capturing that texture and sending it through a new AVPlayer setup, but AirPlay still grabs the original, unprocessed video instead of the final, fully-rendered output. It's also clear that the airplayed video has the full length of the original built in so it's not even that it's 'live streaming' the wrong feed. I need help figuring out how to make AirPlay stream the live, processed video with all the effects, not just the raw video. Any ideas? Happy to share my code if that helps but I'm not sure I have the right underlying approach yet. Thanks!

Is it possible to animate some property on a RealityKit component? For example, the OpacityComponent has an opacity property that allows the opacity of the entities it's attached to, to be modified. I would like to animate the property so the entity fades in and out. I've been looking at the animation API for RealityKit and it either assumes the animation is coming from a USDZ (which this is not), or it allows properties of entities themselves to be animated using a BindTarget. I'm not sure how either can be adapted to modify component properties? Am I missing something? Thanks

I am trying to make a shader that resembles a laser like this: I've been experimenting with a basic Fresnel shader to start, but the Fresnel shader has a problem at high viewing angles where the top has a very different color than the rest of the capsule. This might work for a laser shader once inverted and fine tuned: However, when viewed from the top, it doesn't look so good anymore: Ideally, the purple edge is always ONLY on the edge, and the rest of the surface is the light pink color, no matter the viewing angle. How can I accomplish this to create something that looks like a laser?