Hello, I'm writing an EntityAction that animates a material base tint between two different colours. However, the colour that is being actually set differs in RGB values from that requested. For example, trying to set an end target of R0.5, G0.5, B0.5, results in a value of R0.735357, G0.735357, B0.735357. I can also see during the animation cycle that intermediate actual tint values are also incorrect, versus those being set. My understanding is the the values of material base colour are passed as a SIMD4. Therefore I have a couple of helper extensions to convert a UIColor into this format and mix between two colours. Note however, I don't think the issue is with this functions - even if their outputs are wrong, the final value of the base tint doesn't match the value being set. I wondered if this was a colour space issue? import simd import RealityKit import UIKit typealias Float4 = SIMD4<Float> extension Float4 { func mixedWith(_ value: Float4, by mix: Float) -> Float4 { Float4( simd_mix(x, value.x, mix), simd_mix(y, value.y, mix), simd_mix(z, value.z, mix), simd_mix(w, value.w, mix) ) } } extension UIColor { var float4: Float4 { var r: CGFloat = 0.0 var g: CGFloat = 0.0 var b: CGFloat = 0.0 var a: CGFloat = 0.0 getRed(&r, green: &g, blue: &b, alpha: &a) return Float4(Float(r), Float(g), Float(b), Float(a)) } } struct ColourAction: EntityAction { let startColour: SIMD4<Float> let targetColour: SIMD4<Float> var animatedValueType: (any AnimatableData.Type)? { SIMD4<Float>.self } init(startColour: UIColor, targetColour: UIColor) { self.startColour = startColour.float4 self.targetColour = targetColour.float4 } static func registerEntityAction() { ColourAction.subscribe(to: .updated) { event in guard let animationState = event.animationState else { return } let interpolatedColour = event.action.startColour.mixedWith(event.action.targetColour, by: Float(animationState.normalizedTime)) animationState.storeAnimatedValue(interpolatedColour) } } } extension Entity { func updateColour(from currentColour: UIColor, to targetColour: UIColor, duration: Double, endAction: @escaping (Entity) -> Void = { _ in }) { let colourAction = ColourAction(startColour: currentColour, targetColour: targetColour, endedAction: endAction) if let colourAnimation = try? AnimationResource.makeActionAnimation(for: colourAction, duration: duration, bindTarget: .material(0).baseColorTint) { playAnimation(colourAnimation) } } } The EntityAction can only be applied to an entity with a ModelComponent (because of the material), so it can be called like so: guard let modelComponent = entity.components[ModelComponent.self], let material = modelComponent.materials.first as? PhysicallyBasedMaterial else { return } let currentColour = material.baseColor.tint let targetColour = UIColor(_colorLiteralRed: 0.5, green: 0.5, blue: 0.5, alpha: 1.0) entity.updateColour(from:currentColour, to: targetColour, duration: 2)

I have a visionOS app that I’m adding support for IOS and will like to keep using RealityView. I know there are the following modifiers to add some navigation .realityViewCameraControls(.orbit) .realityViewCameraControls(.dolly) .realityViewCameraControls(.pan) But how can I add more than one? For example I would like to orbit with one finger, Pan with 2 fingers and dolly by pinching. Is this possible and if so can someone share some sample code on how to achieve that? Thanks, Guillermo

When importing FBX animations (generated by Cinema 4d or Blender) the models come in very far way and cannot resize or zoomed in. I have tried every setting from both programs to no avail. Is there a secret to providing the right export options? When importing without animations/and rigging the model imports fine and correct size. But once motion is included, something is awry. I also tried changing base units in Converter, but did not work. I have attache my model heirarchy in C4D as well as the imported result. It appears the animation is imported, as I can see it move, but can barely see it :)

Hello, I am trying to use the subdivision mesh rendering option. I can see it working in RealityComposerPro: But not when loading asset and displaying in Simulator: Using this code: import SwiftUI import RealityKit import RealityKitContent struct AirspaceView: View { // MARK: - VIEW BODY var body: some View { RealityView { content in if let a = try? await Entity(named: "Models/Test/Test.usdc", in: realityKitContentBundle) { content.add(a) } } } } Any ideas why?

Hi everyone, I’m experiencing a critical issue with USDZ files created in Reality Composer on an iPad 9th Generation (iPadOS 18.3). The files work perfectly on iPads from the 10th Generation onwards and on iPad Pros. However, on older devices like the iPad 9th Generation and older iPhones, QuickLook (file preview) crashes when opening them. This is a major issue because these USDZ files are part of an exhibition where artworks are extended with AR elements via a web page. If some visitors cannot view the 3D content, it significantly impacts the experience. What’s puzzling is that two years ago, we exported USDZ files from Reality Composer, made them available via a website, and they worked flawlessly on all devices, including older iPads and iPhones. Now, with the latest iPadOS, they consistently crash on older devices. Has anyone encountered a similar issue? Are there known limitations with QuickLook on older devices, or is there a way to optimize the USDZ files to prevent crashes? Could this be related to changes in iPadOS or RealityKit? Any advice or workaround would be greatly appreciated! Thanks in advance!

Following the post on https://developer.apple.com/documentation/realitykit/custommaterial it's simple to use shader for materials and get uniforms and params from each vertex. However it's not available for visionOS. Any alternative to use in this case? I want to write shader to fill material by myself. (I have shader experience from web, familiar with fragment shader)

I want to use SwiftUI and RealityView to get AR scene understanding data (ARMeshAnchor) on iOS devices with LiDAR. The only way we can do that is by using ARSession (unless there is another way). However in previous iOS 18 builds there was this function: https://developer.apple.com/documentation/realitykit/spatialtrackingsession/run(_:session:arconfiguration:) , which worked with SpatialTrackingSession and a custom ARSession together. This function in the the latest iOS and Xcode has since been removed in the RealityKit framework but still there on documentation. I also wanted to get ARFaceAnchor data which I still cannot get without ARSession, the closest I can get is by using: let target = AnchoringComponent.Target.face let anchoringComponent = AnchoringComponent(target, trackingMode: .predicted) entity = Entity() entity!.components.set(anchoringComponent) But I still can't find a way to get the current frame (ARFrame) or the anchors ([ARAnchor]) in the view. Alternatively if I use if I use this function: https://developer.apple.com/documentation/realitykit/spatialtrackingsession/run(_:) and start the ARSession separately. The session (didUpdate and didAdd) only runs for a few frames before getting interrupted. And if I completely remove SpatialTrackingConfiguration and just run the ARSession. There still is a valid tracked entity for the AnchoringComponent.Target.face component. IF in the configuration for the ARSession I use the ARWorldTrackingConfiguration with face tracking. And I still get updated facial data each frame. But the ARSession didUpdate or didAdd functions don't get called passed the first few frames. Interestingly if I switch the RealityViewCameraContent.RealityViewCamera to .virtual. I get ARMeshAnchor and ARFaceAnchor data, but no camera feed (as expected). This with or without SpatialTrackingConfiguration. My overarching question is what is the proper way to access ARMeshAnchors and other ARAnchors created by the system and track them live while also using SwiftUI. GitHub Repo with sample project can be found here: https://github.com/bpate75/RealityViewTesting

I'm trying to build a Shader in "Reality Composer Pro" that updates from a start time. Initially I tried the following: The idea was that when the startTime was 0, the output would be 0, but then I would set startTime from within code and this would be compared with the current GPU time, and difference used to drive another part of the shader graph: if let testEntity = root.findEntity(named: "Test"), var shaderGraphMaterial = testEntity.components[ModelComponent.self]?.materials.first as? ShaderGraphMaterial { let time = CFAbsoluteTimeGetCurrent() try! shaderGraphMaterial.setParameter(name: "StartTime", value: .float(Float(time))) testEntity.components[ModelComponent.self]?.materials[0] = shaderGraphMaterial } However, I haven't found a reference to the time the shader would be using. So now I am trying to write an EntityAction to achieve the same effect. Instead of comparing a start time to the GPU's time I'm trying to animate one of the shader's uniform input. However, I'm not sure how to specify the bind target. Here's my attempt so far: import RealityKit struct ShaderAction: EntityAction { let startValue: Float let targetValue: Float var animatedValueType: (any AnimatableData.Type)? { Float.self } static func registerEntityAction() { ShaderAction.subscribe(to: .updated) { event in guard let animationState = event.animationState else { return } let value = simd_mix(event.action.startValue, event.action.targetValue, Float(animationState.normalizedTime)) animationState.storeAnimatedValue(value) } } } extension Entity { func updateShader(from startValue: Float, to targetValue: Float, duration: Double) { let fadeAction = ShaderAction(startValue: startValue, targetValue: targetValue) if let shaderAnimation = try? AnimationResource.makeActionAnimation(for: fadeAction, duration: duration, bindTarget: .material(0).customValue) { playAnimation(shaderAnimation) } } } ''' Currently when I run this I get an assertion failure: 'Index out of range (operator[]:line 797) index = 260, max = 8' Furthermore, even if it didn't crash I don't understand how to pass a binding to the custom shader value "startValue". Any clues of how to achieve this effect - even if it's a completely different 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