So, I was trying to animate a single bone using FromToByAnimation, but when I start the animation, the model instead does the full body animation stored in the availableAnimations. If I don't run testAnimation nothing happens. If I run testAnimation I see the same animation as If I had called entity.playAnimation(entity.availableAnimations[0],..) here's the full code I use to animate a single bone: func testAnimation() { guard let jawAnim = jawAnimation(mouthOpen: 0.4) else { print("Failed to create jawAnim") return } guard let creature, let animResource = try? AnimationResource.generate(with: jawAnim) else { return } let controller = creature.playAnimation(animResource, transitionDuration: 0.02, startsPaused: false) print("controller: \(controller)") } func jawAnimation(mouthOpen: Float) -> FromToByAnimation<JointTransforms>? { guard let basePose else { return nil } guard let index = basePose.jointNames.firstIndex(of: jawBoneName) else { print("Target joint \(self.jawBoneName) not found in default pose joint names") return nil } let fromTransforms = basePose.jointTransforms let baseJawTransform = fromTransforms[index] let maxAngle: Float = 40 let angle: Float = maxAngle * mouthOpen * (.pi / 180) let extraRot = simd_quatf(angle: angle, axis: simd_float3(x: 0, y: 0, z: 1)) var toTransforms = basePose.jointTransforms toTransforms[index] = Transform( scale: baseJawTransform.scale * 2, rotation: baseJawTransform.rotation * extraRot, translation: baseJawTransform.translation ) let fromToBy = FromToByAnimation<JointTransforms>( jointNames: basePose.jointNames, name: "jaw-anim", from: fromTransforms, to: toTransforms, duration: 0.1, bindTarget: .jointTransforms, repeatMode: .none, ) return fromToBy } PS: I can confirm that I can set this bone to a specific position if I use guard let index = newPose.jointNames.firstIndex(of: boneName) ... let baseTransform = basePose.jointTransforms[index] newPose.jointTransforms[index] = Transform( scale: baseTransform.scale, rotation: baseTransform.rotation * extraRot, translation: baseTransform.translation ) skeletalComponent.poses.default = newPose creatureMeshEntity.components.set(skeletalComponent) This works for manually setting the bone position, so the jawBoneName and the joint-transformation can't be that wrong.

Two issues: No matter what I set in try audioSession.setPreferredSampleRate(x) the sample rate on both iOS and macOS is always 48000 when the output goes through the speaker, and 24000 when my Airpods connect to an iPhone/iPad. Now, I'm checking the current output loudness to animate a 3D character, using mixerNode.installTap(onBus: 0, bufferSize: y, format: nil) { [weak self] buffer, time in Task { @MainActor in // calculate rms and animate character accordingly but any buffer size under 4800 is just ignored and the buffers I get are 4800 sized. This is ok, when the sampleRate is currently 48000, as 10 samples per second lead to decent visual results. But when AirPods connect, the samplerate is 24000, which means only 5 samples per second, so the character animation looks lame. My AVAudioEngine setup is the following: audioEngine.connect(playerNode, to: pitchShiftEffect, format: format) audioEngine.connect(pitchShiftEffect, to: mixerNode, format: format) audioEngine.connect(mixerNode, to: audioEngine.outputNode, format: nil) Now, I'd be fine if the outputNode runs at whatever if it needs, as long as my tap would get at least 10 samples per second. PS: Specifying my favorite format in the let format = AVAudioFormat(standardFormatWithSampleRate: 48_000, channels: 2)! mixerNode.installTap(onBus: 0, bufferSize: y, format: format) doesn't change anything either

I want an AR character to be able to look at a position while still playing the characters animation. So far, I managed to manually adjust a single bone rotation using skeletalComponent.poses.default = Transform( scale: baseTransform.scale, rotation: lookAtRotation, translation: baseTransform.translation ) which I run at every rendering update, while a full body animation is running. But of course, hardcoding single joints to point into a direction (in my case the head) does not look as nice, as if I were to run some inverse cinematic that includes, hips + neck + head joints. I found some good IKRig code in Composing interactive 3D content with RealityKit and Reality Composer Pro. But when I try to adjust rigs while animations are playing, the animations are usually winning over the IKRig changes to the mesh.

I thought the ARCoachingOverlayView was a nice touch, so each apps ARKit coaching was recognizable and I used it in my ARView/ARSCNView based apps. Now with RealityView, is there any replacement planned? Or should we just use UIViewRepresentable and wrap ARCoachingOverlayView?

In our app, we're streaming short HLS streams to local AVPlayers. In the view we have an AVPlayerLayer which is connected to the AVPlayer we start, and usually we hear audio and see the video. Sometimes, instead of video, we'll see a grey screen, while still being able to hear the audio. The playerlayer will be a shade of grey, which is not a shade coming from our app. Also if for testing purposes we don't connect the player to the PlayerLayer, this grey color will not be there, so it's definitely coming from the AVPlayerLayer. If this is somehow related to an HLSStream becoming corrupted or something, what are the API's in AVFoundation we could use to debug this? So far, when this happens we see no peculiar catch blocks or errors being thrown in our debug logs.

So, I'm using some small python script that imports from pxr import Usd, Sdf, UsdGeom, Kind which used to work fine a few months ago. I got the USD tools from https://developer.apple.com/augmented-reality/tools/ and always had to run it in a Rosetta-Terminal (plus making sure the USD tools are in PATH and PYTHONPATH) but it worked. Now, whatever I do I always get   File "create_scene.py", line 2, in <module>     from pxr import Usd, Sdf, UsdGeom, Kind   File "/Applications/usdpython/USD/lib/python/pxr/Usd/__init__.py", line 24, in <module>     import _usd ModuleNotFoundError: No module named '_usd' Does anyone have any clues what this _usd is about?

Today I was surprised that the latest version of Three.js (browser based 3D Engine) actually supports a transmission property for transparent materials that looks pretty good and is really performant: So far I have only used this material property when rendering in Blender, not in a realtime engine. But if THREE can run this at 60fps in the browser, there must be a way of achieving the same in ARKit/SceneKit/RealityKit? I just haven't found anything in the SCNMaterial documentation about Transmission nor anyone mentioning relevant shader modifiers. Especially if we want to present objects with frosted glas effects in AR this would be super useful? (The Three.js app for reference: https://q2nl8.csb.app/ and I learned about this in an article by Kelly Mulligan: https://tympanus.net/codrops/2021/10/27/creating-the-effect-of-transparent-glass-and-plastic-in-three-js/)

Basically, take just the Xcode 26 AR App template, where we put the ContentView as the detail end of a NavigationStack. Opening app, the app uses < 20MB of memory. Tapping on Open AR the memory usage goes up to ~700MB for the AR Scene. Tapping back, the memory stays up at ~700MB. Checking with Debug memory graph I can still see all the RealityKit classes in the memory, like ARView, ARRenderView, ARSessionManager. Here's the sample app to illustrate the issue. PS: To keep memory pressure on the system low, there should be a way of freeing all the memory the AR uses for apps that only occasionally show AR scenes.