I'm trying to position an Entity with inverse kinematics while dragging the handle only, but use forward kinematics (pose jointTransforms) otherwise. The System, Components, Gestures and Rig all seem to work individually. My approach is to add the IKComponent when dragging starts on the handle and removing the IKComponent it is released. The switch into IK works, but when removing the IKComponent the App crashes * thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x8) * frame #0: 0x00000001aa5bb188 CoreRE`(anonymous namespace)::IKComponentSolverWrapper::getSolver() + 60 frame #1: 0x00000001aa5bafb0 CoreRE`re::internal::ikParametersNodeCallback(re::Slice<re::StringID>, re::Slice<re::RigDataValue>, re::Slice<re::StringID>, re::MutableSlice<re::RigDataValue>, void*) + 48 frame #2: 0x00000001aa52d090 CoreRE`re::(anonymous namespace)::resolveEvaluationContextCallback(re::EvaluationContext&, void*) + 152 frame #3: 0x00000001aa68c024 CoreRE`re::(anonymous namespace)::$_76::__invoke(re::Slice<unsigned long>, re::(anonymous namespace)::RegisterTable&) + 1080 frame #4: 0x00000001aa678c94 CoreRE`re::EvaluationModelSingleThread::evaluate(re::EvaluationContextSlices&) + 1188 frame #5: 0x00000001aa866984 CoreRE`re::SkeletalPoseRuntimeData::executeEvaluationTree() + 136 frame #6: 0x00000001aadf37ec CoreRE`re::ecs2::SkeletalPoseComponent::calculateSkeletalPoseBufferWithRig(re::ecs2::MeshComponent*, re::ecs2::RigComponent*, re::ecs2::SkeletalPoseBufferComponent*) + 492 frame #7: 0x00000001aadf4a84 CoreRE`re::ecs2::SkeletalPoseComponentStateImpl::processPreparingComponents(re::ecs2::System::UpdateContext const&, re::ecs2::BasicComponentStateSceneData<re::ecs2::SkeletalPoseComponent>*, re::ecs2::ComponentBuckets<re::ecs2::SkeletalPoseComponent>::BucketIteration, void*) + 268 frame #8: 0x00000001aadf54b0 CoreRE`re::ecs2::SkeletalPoseSystem::update(re::ecs2::System::UpdateContext) const + 732 frame #9: 0x00000001aaed3e54 CoreRE`re::internal::Callable<re::ecs2::ECSManager::configurePhaseECSSystems(re::Scheduler::ScheduleDescriptor&, re::ecs2::ECSSystemGroup, unsigned long)::$_1, void (float)>::operator()(float&&) const + 168 frame #10: 0x00000001ab40eda4 CoreRE`re::Scheduler::executePhase(unsigned long) + 440 frame #11: 0x00000001aa6a3b74 CoreRE`re::Engine::executePhase(re::FramePhase) + 144 frame #12: 0x000000023173de9c RealitySystemSupport`RCPSharedSimulationExecuteUpdate + 64 frame #13: 0x00000002276c9820 MRUIKit`__65-[MRUISharedSimulation _doJoinWithConnectionConfiguration:error:]_block_invoke.35 + 168 frame #14: 0x00000002276c8530 MRUIKit`__addCAPreFenceHandler_block_invoke + 32 frame #15: 0x000000018af22058 QuartzCore`CA::Transaction::run_commit_handlers(CATransactionPhase) + 112 frame #16: 0x000000018aef2ad4 QuartzCore`CA::Context::commit_transaction(CA::Transaction*, double, double*) + 592 frame #17: 0x000000018af21898 QuartzCore`CA::Transaction::commit() + 652 frame #18: 0x000000018af22dac QuartzCore`CA::Transaction::flush_as_runloop_observer(bool) + 68 frame #19: 0x0000000185a26820 UIKitCore`_UIApplicationFlushCATransaction + 48 frame #20: 0x0000000184f97af0 UIKitCore`_UIUpdateSequenceRun + 76 frame #21: 0x0000000185954290 UIKitCore`schedulerStepScheduledMainSection + 168 frame #22: 0x00000001859536d8 UIKitCore`runloopSourceCallback + 80 frame #23: 0x00000001804157fc CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 24 frame #24: 0x0000000180415744 CoreFoundation`__CFRunLoopDoSource0 + 172 frame #25: 0x0000000180414eb0 CoreFoundation`__CFRunLoopDoSources0 + 232 frame #26: 0x000000018040f454 CoreFoundation`__CFRunLoopRun + 788 frame #27: 0x000000018040ecd4 CoreFoundation`CFRunLoopRunSpecific + 552 frame #28: 0x0000000190104b70 GraphicsServices`GSEventRunModal + 160 frame #29: 0x0000000185a27e30 UIKitCore`-[UIApplication _run] + 796 frame #30: 0x0000000185a2c058 UIKitCore`UIApplicationMain + 124 frame #31: 0x00000001d29558b4 SwiftUI`closure #1 (Swift.UnsafeMutablePointer<Swift.Optional<Swift.UnsafeMutablePointer<Swift.Int8>>>) -> Swift.Never in SwiftUI.KitRendererCommon(Swift.AnyObject.Type) -> Swift.Never + 164 frame #32: 0x00000001d29555dc SwiftUI`SwiftUI.runApp<τ_0_0 where τ_0_0: SwiftUI.App>(τ_0_0) -> Swift.Never + 84 frame #33: 0x00000001d265ecdc SwiftUI`static SwiftUI.App.main() -> () + 164 frame #34: 0x000000010303f1c4 Playground.debug.dylib`static PlaygroundApp.$main() at <compiler-generated>:0 frame #35: 0x000000010303f290 Playground.debug.dylib`main at PlaygroundApp.swift:7:8 frame #36: 0x0000000102f6d410 dyld_sim`start_sim + 20 frame #37: 0x000000010312e274 dyld`start + 2840 Is there a workaround or another way to switch between IK and FK?

Hey, I am having issues getting my Material X shaders to work properly in Reality Composer Pro that I've authored in Houdini. The shader is very simple. It starts with a tiled image node that is written to the diffuse color of the preview surface node. This node is called mtxltileimage2. When I create a tiled image node in RCP and configure it to have the same parameter values I get the texture to show up correctly. This node is called TiledImage. One difference I can identify is that the second node has a grey icon whereas the first node has a blue icon. Could this be related to this issue? Here is the USD viewer output for the two variants of the tiled image node. Any pointers, misconceptions and help would be greatly appreciated. My goal is to be able and author these shaders in Houdini and import them into RCP. Trying to figure out the right pipeline for this workflow.

https://developer.apple.com/documentation/arkit/arkit_in_ios/specifying_a_lighting_environment_in_ar_quick_look How can I disable it? or at least use a custom texture that's just black? I don't see the purpose of having the real-time environment probe that captures IBL, but always add this fake studio IBL that you can't remove...

Starting with iOS 18.0 beta 1, I've noticed that RealityKit frequently crashes in the simulator when an app launches and presents an ARView. I was able to create a small sample app with repro steps that demonstrates the issue, and I've submitted feedback: FB16144085 I've included a crash log with the feedback. If possible, I'd appreciate it if an Apple engineer could investigate and suggest a workaround. It's awkward to be restricted to the iOS 17 simulator, which does not exhibit this behavior. Please let me know if there's anything I can do to help. Thank you.

If I have one portal on the ceiling and one on the floor, can a tall Entity cross multiple portals at once? Will the opposing portal directions cause it to fail? No matter what I try for the crossingMode and clippingMode of the PortalComponent I can only get it to fully work for one portal at a time. I have tried flipping the normals for the crossingMode and clippingMode planes. I have also tried creating a ceiling portal plane with inverted normals. It seems like whatever Entity is passing through a portal has one portal it wants to deal with at a time and that's it. My other option is to create portals using occlusion but I prefer the simplest way.

Hi, I wanted to do something quite simple: Put a box on a wall or on the floor. My box: let myBox = ModelEntity( mesh: .generateBox(size: SIMD3<Float>(0.1, 0.1, 0.01)), materials: [SimpleMaterial(color: .systemRed, isMetallic: false)], collisionShape: .generateBox(size: SIMD3<Float>(0.1, 0.1, 0.01)), mass: 0.0) For that I used Plane Detection to identify the walls and floor in the room. Then with SpatialTapGesture I was able to retrieve the position where the user is looking and tap. let position = value.convert(value.location3D, from: .local, to: .scene) And then positioned my box myBox.setPosition(position, relativeTo: nil) When I then tested it I realized that the box was not parallel to the wall but had a slightly inclined angle. I also realized if I tried to put my box on the wall to my left the box was placed perpendicular to this wall and not placed on it. After various searches and several attempts I ended up playing with transform.matrix to identify if the plane is wall or a floor, if it was in front of me or on the side and set up a rotation on the box to "place" it on the wall or a floor. let surfaceTransform = surface.transform.matrix let surfaceNormal = normalize(surfaceTransform.columns.2.xyz) let baseRotation = simd_quatf(angle: .pi, axis: SIMD3<Float>(0, 1, 0)) var finalRotation: simd_quatf if acos(abs(dot(surfaceNormal, SIMD3<Float>(0, 1, 0)))) < 0.3 { logger.info("Surface: ceiling/floor") finalRotation = simd_quatf(angle: surfaceNormal.y > 0 ? 0 : .pi, axis: SIMD3<Float>(1, 0, 0)) } else if abs(surfaceNormal.x) > abs(surfaceNormal.z) { logger.info("Surface: left/right") finalRotation = simd_quatf(angle: surfaceNormal.x > 0 ? .pi/2 : -.pi/2, axis: SIMD3<Float>(0, 1, 0)) } else { logger.info("Surface: front/back") finalRotation = baseRotation } Playing with matrices is not really my thing so I don't know if I'm doing it right. Could you tell me if my tests for the orientation of the walls are correct? During my tests I don't always correctly identify whether the wall is in front or on the side. Is this generally the right way to do it? Is there an easier way to do this? Regards Tof

Hey I wanted to make an app that tracks changes in the room and room lightning and I was wondering if its possible to use VirtualEnvironmentProbeComponent to obtain the EnvironmentResource image and store it? If so are there any example of similar operation I could use? Thank you!

I have a 3D model with morphing animation that works correctly in Blender. I exported this model as a USDZ file and tried to display it in an Xcode-developed visionOS app, but the morphing animation does not play. What I Have Tried: Morphing animation works correctly in Blender. After exporting to USDZ, the morphing animation does not play in the Xcode app. Linear motion animations (such as object movement) work fine. Behavior in Reality Converter: GLB files do not display. USDZ files load, but morphing animations do not play. What I Want to Know: Is there a way to play morphing animations in an Xcode-developed app? Does RealityKit support morphing animations? Can morphing animations be played in an Xcode-developed app? If RealityKit does not support morphing animations, what alternative methods can be used to play them? I am looking for a way to use the existing animations without recreating them. Additional Information: I have both the Blender file (where animations work) and the USDZ file (where animations do not play). I am developing a visionOS app using Xcode. Any advice or solutions would be greatly appreciated. Thank you in advance!

The farther away the center of a large entity is, the less accurate the positioning is? For example I am changing only the y-axis position of an entity that is tens of meters long, but i notice x and z drifting slowly the farther away the center of the entity is. I would not expect the x and z to move. It might be compounding rounding errors somewhere, or maybe the RealityKit engine is deciding not to be super precise about distant objects? Otherwise I just have a bug somewhere.

as in the environments we have real tiem reflections of movies on a screen or reflections of the surrounding hood in the background... could i get a metallic surface getting accurate reflections of a box on top ? i don't mean getting a rpobe or hdr cubemap, i mean the same accurate reflections as the water of the mt hood with movie i'm wacthing in other app

Hey everyone, I am currently developing an app in visionOS and using RealityComposerPro create scenes in put in my app. I have a humanoid model with hair strands, and each strand of hair has an opacity map. However, some reflections are still visible even though the opacity is zero. There are also some weird culling among hair strands (in the left circle) and weird reflections in hair cards (in the right circle). Here's my settings for the materials. Since all the hair strands are interconnected with each other, it is hard to decide the drawing order in Xcode, so I am wondering if there's an easier way to handle transparency objects. Please let me know if you know anything helpful, much appreciated!

Hi Apple, In VisionOS, for real-time streaming of large 3D scenes, I plan to create Metal buffers and textures in multiple threads and then use a compute shader on the main thread to copy the Metal resources into RealityKit, minimizing main thread usage. Given that most of RealityKit's default APIs require execution on the main actor (main thread), it is not ideal for streaming data. Is this approach the best way to handle streaming data and real-time rendering? Thank you very much.

I am currently using RealityKit (perspective camera) to render a character in my swiftUI app. The character has customization such as clothing items and hair and all objects are properly weighted to the rig. The way the model is setup in Blender is like so: Groups of objects that will be swapped (ex: Shoes -> Shoes objects) and an armature. I then export it to usdc with all objects active. This is the resulting entity hierarchy, viewed in Reality Composer Pro: My problem is that when I export with the Armature Modifier applied to the objects, so that animations get exported, the ModelComponent gets flattened to the armature and swapping entities is no longer as simple as removing the entity with the corresponding name. What's the best practice here? Should animation be exported separately and then applied to the skeleton? If so, how is that achieved? I'm not really sure how to proceed here.

I am currently using RealityKit (perspective camera) to render a character in my swiftUI app. The character has customization such as clothing items and hair and all objects are properly weighted to the rig. The way the model is setup in Blender is like so: Groups of objects that will be swapped (ex: Shoes -> Shoes objects) and an armature. I then export it to usdc with all objects active. This is the resulting hierarchy: Before exporting for the animation (armature modifier applied), I simply had to store the Model entities and swap them in but now when I export with the Armature Modifier applied, so that animations get exported, the ModelComponent gets flattened to the armature and swapping entities and applying new materials to them is no longer as simple. Here's a demo blend file and usdc export with a setup like mine, having an animated bone to swing a cube and sphere, to be swapped so that only one is visible https://www.dropbox.com/scl/fo/be2q6qcztc83z7c4gj1w0/AMapxWc_ip2KZ8oTOYDUMv8?rlkey=rcdaggcxq06dyen09mw5mqmem&st=bnc0d7j0&dl=0 This is how I'm loading the entity and removing a part, with the demo files import SwiftUI import RealityKit struct SwapDemoView: View { var body: some View { RealityView { content in let camera = PerspectiveCamera() camera.transform.translation = SIMD3(x: 0, y: 0.1, z: 3) guard let root = try? await Entity(named: "simpleSwapDemo") else { fatalError("simpleSwapDemo.usdc is not present") } print(root) // Get initial hierarchy guard let cube = root.findEntity(named: "Cube") else { fatalError("Entity cube doesn't exist") } cube.removeFromParent() // <-- Cube is still visible after removal print(root) // Get hierarchy to confirm removal of cube let resource = root.availableAnimations[0] root.playAnimation(resource.repeat()) content.add(root) content.add(camera) } .background(.white) } } And this is what the entity hierarchy looks like in RealityKit before cube removal ▿ 'root' : Entity, children: 1 ⟐ SynchronizationComponent ⟐ AnimationLibraryComponent ⟐ Transform ▿ 'Armature' : ModelEntity, children: 2 ⟐ SynchronizationComponent ⟐ ModelComponent ⟐ SkeletalPosesComponent ⟐ AnimationLibraryComponent ⟐ Transform ▿ 'Armature' : Entity ⟐ SynchronizationComponent ⟐ Transform ▿ 'Primitives' : Entity, children: 2 ⟐ SynchronizationComponent ⟐ Transform ▿ 'Sphere' : Entity, children: 1 ⟐ SynchronizationComponent ⟐ Transform ▿ 'Sphere' : Entity ⟐ SynchronizationComponent ⟐ Transform ▿ 'Cube' : Entity, children: 1 ⟐ SynchronizationComponent ⟐ Transform ▿ 'Cube' : Entity ⟐ SynchronizationComponent ⟐ Transform And here's the hierarchy after removal ▿ 'root' : Entity, children: 1 ⟐ SynchronizationComponent ⟐ AnimationLibraryComponent ⟐ Transform ▿ 'Armature' : ModelEntity, children: 2 ⟐ SynchronizationComponent ⟐ ModelComponent ⟐ SkeletalPosesComponent ⟐ AnimationLibraryComponent ⟐ Transform ▿ 'Armature' : Entity ⟐ SynchronizationComponent ⟐ Transform ▿ 'Primitives' : Entity, children: 1 ⟐ SynchronizationComponent ⟐ Transform ▿ 'Sphere' : Entity, children: 1 ⟐ SynchronizationComponent ⟐ Transform ▿ 'Sphere' : Entity ⟐ SynchronizationComponent ⟐ Transform And this is the result: What's the best practice here? Should animation be exported separately and then applied to the skeleton? If so, how is that achieved? I'm not really sure how to proceed here.

I’m building an app that uses RealityKit and specifically ARConfiguration.FrameSemantics.personSegmentationWithDepth. The goal is to insert an AR object into the scene behind a person, and an additional AR object in front of the person, while being as photo realistic as possible. Through testing, I’ve noticed that many times, the edges of the person segmentation mask are not well matched to the actual person, and parts of the person are transparent, with the AR object bleeding through. It’s sort of like a “bad green screen” effect, which I’d expect to see a little bit, but not to this extent. I’ve been testing on iPhone 16, iPhone 14 Pro, iPad Pro 12.9 inch 6th Generation, and iPhone 12 Pro, with similar results across all devices. I’m wondering what else I can do to improve this… either code changes, platform (like different iPhone models), or environment (like lighting, distance, etc). Attaching some example screen grabs and a minimum reproducible code sample. Appreciate any insights! import ARKit import SwiftUI import RealityKit struct RealityViewContainer: UIViewRepresentable { func makeUIView(context: Context) -> ARView { let arView = ARView(frame: .zero) arView.environment.sceneUnderstanding.options.insert(.occlusion) arView.renderOptions.insert(.disableMotionBlur) arView.renderOptions.insert(.disableDepthOfField) let configuration = ARWorldTrackingConfiguration() configuration.planeDetection = [.horizontal] if ARWorldTrackingConfiguration.supportsFrameSemantics(.personSegmentationWithDepth) { configuration.frameSemantics.insert(.personSegmentationWithDepth) } arView.session.run(configuration) arView.session.delegate = context.coordinator context.coordinator.arView = arView } func makeCoordinator() -> Coordinator { Coordinator(self) } class Coordinator: NSObject, ARSessionDelegate { var parent: RealityViewContainer var floorAnchor: ARPlaneAnchor? init(_ parent: RealityViewContainer) { self.parent = parent } func session(_ session: ARSession, didAdd anchors: [ARAnchor]) { if let arView,floorAnchor == nil { for anchor in anchors { if let horizontalPlaneAnchor = anchor as? ARPlaneAnchor, horizontalPlaneAnchor.alignment == .horizontal, horizontalPlaneAnchor.transform.columns.3.y < arView.cameraTransform.translation.y { // filter out ceiling floorAnchor = horizontalPlaneAnchor let backgroundEntity = BackgroundEntity() let anchorEntity = AnchorEntity(anchor: horizontalPlaneAnchor) anchorEntity.addChild(background) let foregroundEntity = ForegroundEntity() backgroundEntity.addChild(foregroundEntity) arView.scene.addAnchor(anchorEntity) arView.installGestures([.rotation, .translation], for: backgroundEntity) break // Stop after adding the first horizontal plane (floor) } } } } } }

I am trying to implement a ChacterControllerComponent using the following URL. https://developer.apple.com/documentation/realitykit/charactercontrollercomponent I have written sample code, but PhysicsSimulationEvents.WillSimulate is not executed and nothing happens. import SwiftUI import RealityKit import RealityKitContent struct ImmersiveView: View { let gravity: SIMD3<Float> = [0, -50, 0] let jumpSpeed: Float = 10 enum PlayerInput { case none, jump } @State private var testCharacter: Entity = Entity() @State private var myPlayerInput = PlayerInput.none var body: some View { RealityView { content in // Add the initial RealityKit content if let immersiveContentEntity = try? await Entity(named: "Immersive", in: realityKitContentBundle) { content.add(immersiveContentEntity) testCharacter = immersiveContentEntity.findEntity(named: "Capsule")! testCharacter.components.set(CharacterControllerComponent()) let _ = content.subscribe(to: PhysicsSimulationEvents.WillSimulate.self, on: testCharacter) { event in print("subscribe run") let deltaTime: Float = Float(event.deltaTime) var velocity: SIMD3<Float> = .zero var isOnGround: Bool = false // RealityKit automatically adds `CharacterControllerStateComponent` after moving the character for the first time. if let ccState = testCharacter.components[CharacterControllerStateComponent.self] { velocity = ccState.velocity isOnGround = ccState.isOnGround } if !isOnGround { // Gravity is a force, so you need to accumulate it for each frame. velocity += gravity * deltaTime } else if myPlayerInput == .jump { // Set the character's velocity directly to launch it in the air when the player jumps. velocity.y = jumpSpeed } testCharacter.moveCharacter(by: velocity * deltaTime, deltaTime: deltaTime, relativeTo: nil) { event in print("playerEntity collided with \(event.hitEntity.name)") } } } } } } The scene is loaded from RCP. It is simple, just a capsule on a pedestal. Do I need a separate code to run testCharacter from this state?

I'm using RealityView in my iOS game mxied with SwiftUI. For the following 2 example usages, the simulator will only render the first RealityView, and the second one is either super laggy or show a black model. Running on the real device is all good, just simualtor has this issue. Have a TabView and each tab has a RealityView. Have a root view and detail view connected via a push navigation, both root and detail have a RealityView. In the Simulator, the second RealityView is going to be very choppy and basically unusable, but on a real iPhone everything looks great. Is this a known simulator issue or I did something bad?

I'm looking to create an effect on iOS that tracks the user's face position with ARKit and shifts nearer/more prominent geometry in the scene around while more "distant" geometry stays fixed to the XY plane - making it look like the geometry on screen "sticks out" I've managed to implement most of this successfully, but it's not perfect when using PerspectiveCameraComponent in RealityKit because as I shift the camera (and change its field of view based on the user's distance) the backplane changes its orientation (it's always orthogonal to camera's direction). I've tried adopting ProjectiveTransformCameraComponent instead. The idea is that the camera shifts around the scene, mirroring the user's head's position, looking at (0,0,0) and the back plane is adjusted to be parallel with the X,Y plane (animation replicated in Blender below). However, I can't manage to set up ProjectiveTransformCameraComponent with an appropriate matrix or update its transform property in a RealityKit System correctly. I also tried setting many simpler projection matrices as described in a number of guides on camera projection matrices on the internet and all I get is a blank view. Does anyone have some guidance on what the projection matrix that ProjectiveTransformCameraComponent expects is meant to look like or how I would go about accomplishing my goal?

I want to use reality to create a custom material that can use my own shader and support Mesh instancing (for rendering 3D Gaussian splating), but I found that CustomMaterial does not support VisionOS. Is there any other interface that can achieve my needs? Where can I find examples?

Hello experts, I'm trying to implement a material with custom shader code, but I saw that visionOS doesn't allow you to inject custom Metal functions or use CustomMaterial like iOS/macOS, nor can you directly write Metal Shading Language (.metal) and use it through ShaderGraphMaterial. So my question is, if i want to implement your own shader code, how should i do it?