Hello, I was looking back into downloading the Tracking geographic locations in AR sample app from https://developer.apple.com/documentation/arkit/tracking-geographic-locations-in-ar Unfortunately the Download links to the .zip of the DisplayingAPointCloudUsingSceneDepth sample project. The exact same issue occurs when trying to download the sample code from https://developer.apple.com/documentation/ARKit/creating-a-fog-effect-using-scene-depth Wondering if those links are deliberately broken because of possible deprecations. Thanks to any Apple Engineer willing to look into that.

my coworkers and i are guessing at what data defines an anchor. i tried searching but struggled to find anything helpful. our best guess was a combination Triangular Irregular Networks (TIN), gps, magnetic compass direction and maybe elevation sensors. is this documented anywhere? if not, can a definition or description be provided?

We're developing an iOS application that integrates RoomCaptureSession with ARSCNView for room scanning. Our implementation differs from the standard RoomCaptureView because we need custom UI guidance with 3D dots placed in the scanning environment to guide users through the capture process. Bug Description: The application crashes when users attempt to scan multiple rooms or apartments in sequence. The crash specifically occurs with the following pattern: User successfully scans first room with multiple hotspots (working correctly) User stops scanning, moves to a new room In the new room, first 1-2 hotspots work correctly Application crashes when attempting to scan additional hotspots Technical Details: Error: SLAM Anchor assertion failure in SlamAnchor.cpp:37 : HasValidPose() Crash occurs in Thread 27 with CAPIDetectionOutputFwdNode Error suggests invalid positioning when placing AR anchors Steps to Reproduce: Start room scan Complete multiple hotspot captures in first room Stop scanning Start new room scan Capture 1-2 hotspots successfully Attempt additional hotspot captures -> crashes Attempted Solutions: Implemented anchor cleanup between sessions Added position validation before anchor placement Implemented ARSession error handling Added proper thread management for AR operations Environment: Device: iPhone 14 Pro (LiDAR equipped) iOS Version: 18.1.1 (22B91) Testing through TestFlight Crash Log Details: Exception Type: EXC_CRASH (SIGABRT) Exception Codes: 0x0000000000000000, 0x0000000000000000 Exception Note: EXC_CORPSE_NOTIFY Triggered by Thread: 27 Thread 27 Crashed: 0 libsystem_kernel.dylib 0x00000001f0cc91d4 __pthread_kill + 8 1 libsystem_pthread.dylib 0x0000000228e12ef8 pthread_kill + 268 2 libsystem_c.dylib 0x00000001a86bbad8 abort + 128 3 AppleCV3D 0x0000000234d71a28 cv3d::vio::capi::SlamAnchor::SlamAnchor Question: Is there a recommended approach for handling multiple room captures with custom ARSCNView integration? The standard RoomCaptureView implementation doesn't show this behavior, but we need the custom guidance functionality that ARSCNView provides. Crash Log Code and full crash logs can be provided if needed.

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

I use ARKit to build an app, scan rooms to collect the spatial data of objects and re-construct the 3D scene. the problem is I found the depth map values captured in ARFrame significantly deviate from the real distances, even nonlinearly, for the distances below 1.5m, values are basically correct, but beyond 1.5m, they are smaller than real values. for example read 1.9m from the generated depthmap.tiff, but real distance is 3 meters. below is my code of generating tiff file to record depth map data: Generated TIFF file (captured from ARKit): as shown above, the maximum distance is around 1.9m, but real distance to that wall is more than 3 meters, and also you can see, the depth map picture captured in ARKit is quite blurry, particularly at far distance (> 2.0m), almost smeared out. Generated TIFF file (captured from AVFoundation): In comparison, the depth map captured from traditional AVFoundation and with the same hardware device is much clear, the values seem not in meter unit though.

Hi, since iOS 15 I've repeatedly noticed the console warning »ARSessionDelegate is retaining X ARFrames. This can lead to future camera frames being dropped« even for rather simple projects using RealityKit and ARKit. Could someone from the ARKit team please elaborate what causes this warning and what can be done to avoid it? If I remember correctly I didn't even assign an ARSessionDelegate. Thank you!

Description: I'm developing an AR effect using SceneKit and applying a transparent material to a face mesh. However, I'm facing an issue where the front faces of the mesh overlap each other, causing incorrect rendering. Problem: The front faces of the mesh overlap with each other when transparency is applied. This causes areas like the cheeks to be visible through the nose, even though they should be occluded. Expected Behavior: The material should behave as if it were opaque to itself—that is, overlapping front faces should be occluded properly, while still allowing transparency for background elements. Actual Behavior: The mesh renders its own front faces incorrectly, making parts of the face visible through others when they should be blocked. What I Have Tried: testMaterial.writesToDepthBuffer = true testMaterial.readsFromDepthBuffer = true Question: 👉 How can I prevent SceneKit's transparent material from rendering overlapping front faces? 👉 Is there a way to force SceneKit to treat its own mesh as opaque for itself while still being transparent to the background? 👉 Does SceneKit support a proper depth pre-pass or an equivalent to Unity’s ZWrite shaders to solve this issue? Attached screenshots demonstrate the problem visually. Any help would be greatly appreciated! 🚀