Hello, in our app we are downloading some user generated content (.reality files and USDZs) and displaying it within the app. This worked without issues in iOS 14 but with iOS 15 (release version) there have been a lot of issues with certain .reality files. As far as I can see USDZ files still work. I've created a little test project and the error message log is not really helpful. 2021-10-01 19:42:30.207645+0100 RealityKitAssetTest-iOS15[3239:827718] [Assets] Failed to load asset of type 'RealityFileAsset', error:Could not find archive entry named assets/Scéna17_9dfa3d0.compiledscene. 2021-10-01 19:42:30.208097+0100 RealityKitAssetTest-iOS15[3239:827598] [Assets] Failed to load asset path '#18094855536753608259' 2021-10-01 19:42:30.208117+0100 RealityKitAssetTest-iOS15[3239:827598] [Assets] AssetLoadRequest failed because asset failed to load '#18094855536753608259' 2021-10-01 19:42:30.307040+0100 RealityKitAssetTest-iOS15[3239:827598] throwing -10878 2021-10-01 19:42:30.307608+0100 RealityKitAssetTest-iOS15[3239:827598] throwing -10878 2021-10-01 19:42:30.307712+0100 RealityKitAssetTest-iOS15[3239:827598] throwing -10878 2021-10-01 19:42:30.307753+0100 RealityKitAssetTest-iOS15[3239:827598] throwing -10878 2021-10-01 19:42:30.307790+0100 RealityKitAssetTest-iOS15[3239:827598] throwing -10878 2021-10-01 19:42:30.307907+0100 RealityKitAssetTest-iOS15[3239:827598] throwing -10878 2021-10-01 19:42:30.307955+0100 RealityKitAssetTest-iOS15[3239:827598] throwing -10878 2021-10-01 19:42:30.308155+0100 RealityKitAssetTest-iOS15[3239:827598] throwing -10878 2021-10-01 19:42:30.308194+0100 RealityKitAssetTest-iOS15[3239:827598] throwing -10878 ▿ Failed to load loadRequest.   - generic: "Failed to load loadRequest." Basic code structure that is used for loading: cancellable = Entity.loadAsync(named: entityName, in: .main)     .sink { completion in         switch completion {         case .failure(let error):             dump(error)             print("Done")         case .finished:             print("Finished loading")         }     } receiveValue: { entity in         print("Entity: \(entity)")     } Is there anyway to force it to load in a mode that enforces compatibility? As mentioned this only happens on iOS 15. Even ARQuickLook can't display the files anymore (no issues on iOS 14). Thanks for any help!

Hello, I've been looking all over the place but so far I haven't found a trivial way to grab ARView's current timestamp. So basically the elapsed time since the scene started rendering. I can access that in the Surface and Geometry shaders but I would like to pass a timestamp as a parameter in order to drive shader animations. I feel that's more efficient than injecting animation progress manually on every frame, especially if there are lot's of objects with that shader. So far what I've done is subscribing to the Scenes Update event and using the delta time to calculate the elapsed time myself. But this is quite error prone and tends to break when I present the scene a second time (e.g closing and reopening to AR experience). The only other option I found was using a render callback and to grab the time property from the PostProcessContext. That works well but do I really have to go that route? Would be great if there is an easy way to achieve this. Pretty much an equivalent to this: https://developer.apple.com/documentation/scenekit/scnscenerenderer/1522680-scenetime NOTE: I'm not looking for the timestamp of the ARSessions current frame. Thank you!

I've just implemented some necessary fixes to our app to ensure compatibility with iOS 15 and ARKit 2. Now when I deploy the app via XCode 13 RC (Version 13.0 (13A233)) I get the following crash right at launch: dyld: Library not loaded: /System/Library/Frameworks/RealityFoundation.framework/RealityFoundation   Referenced from: /private/var/containers/Bundle/Application/…   Reason: image not found dyld: launch, loading dependent libraries DYLD_LIBRARY_PATH=/usr/lib/system/introspection DYLD_INSERT_LIBRARIES=/Developer/usr/lib/libBacktraceRecording.dylib:/Developer/usr/lib/libMainThreadChecker.dylib:/Developer/Library/PrivateFrameworks/DTDDISupport.framework/libViewDebuggerSupport.dylib Is this a known issue? I've already tried deleting Derived Data and clearing the project but the problem persists. The minimum deployment target is iOS 13 for the main app and iOS 14 for the AppClip. All iOS 15 related fixes are wrapped into if #available(iOS 15.0, *) { … } This is a pretty major problem for us as we now can't send out Testflights or upload to AppStoreConnect for Monday. Thanks!

Hi, is there a way to force RealityKit to compile/prewarm and cache all shaders that will be used within a Scene in advance – ideally in the background? This would be useful for adding complex models to the scene which sometimes can cause quite a couple dropped frames even on the newest devices (at least I assume the initial delay when displaying them is caused by the shader compilation) but also for CustomMaterials. Note this also happens with models that are loaded asynchronously. Thanks!

Hello, I have a usecase where I need to to download and compile metal shaders on demand as strings or .metal files. These should then be used for CustomMaterials and/or postprocessing within RealityKit. Essentially this boils down to having raw source code that needs to be compiled at runtime. My plan was to use the method makeLibrary(source:options:completionHandler:) to accomplish this. The problem is that I get the following error during compilation: RealityKitARExperienceAssetProvider: An error occured while trying to compile shader library »testShaderLibrary« - Error Domain=MTLLibraryErrorDomain Code=3 "program_source:2:10: fatal error: 'RealityKit/RealityKit.h' file not found #include <RealityKit/RealityKit.h> My code for creating the library looks like this (simplified example): let librarySourceString: String = """ #include <metal_stdlib> #include <RealityKit/RealityKit.h> using namespace metal; [[visible]] void mySurfaceShader(realitykit::surface_parameters params) {     params.surface().set_base_color(half3(1, 1, 1)); } """ mtlDevice.makeLibrary(source: librarySourceString, options: nil) { library, error in     if let error = error {         dump(error) return     }     // do something with library } So I'm wondering if there's a way to tell the metal compiler how to resolve this reference to the RealityKit header file? Would I need to replace that part of the source string maybe with an absolute path to the RealityKit framework (if so – how would I get this at runtime)? Appreciate any hints - thanks!