Hi, The metal-cpp distribution appears to only contain headers for Foundation and Quartzcore. The LearnMetalCPP download [1] provides a ZIP with an metal-cpp-extensions directory containing AppKit.hpp and MetalKit.hpp headers. First question: Are these headers distributed anywhere else more publicly? Without these headers only the renderer can be fully written in C++ as far as I can tell, i.e. no complete C++ NSApplication. Second question: Will these headers, if needed, be maintained (e.g. updated and/or extended) by Apple along side metal-cpp? [1] https://developer.apple.com/metal/cpp/ Thank you and regards.

I searched the Metal Shading Language Specification Version 3.0 document, however I cannot see any function for inverting a matrix. Is there really no function in Metal for inverting a matrix? I often need to this in linear equations and have so far resorted to writing the necessary function each time, most of the time just copy-and-pasting code. inverse exists in SIMD and GLSL, so why not in Metal? It seems so unexpected that this function does not exist that I am almost certain I have just overlooked something obvious. I even tried 1 / M, to no avail.

I have a model that uses a video material as the surface shader and I need to also use a geometry modifier on the material. This seemed like it would be promising (adapted from https://developer.apple.com/wwdc21/10075 ~5m 50s). // Did the setup for the video and AVPlayer eventually leading me to let videoMaterial = VideoMaterial(avPlayer: avPlayer) // Assign the material to the entity entity.model!.materials = [videoMaterial] // The part shown in WWDC: Set up the library and geometry modifier before, so now try to map the new custom material to the video material entity.model!.materials = entity.model!.materials.map { baseMaterial in       try! CustomMaterial(from: baseMaterial, geometryModifier: geometryModifier)     } But, I get the following error Thread 1: Fatal error: 'try!' expression unexpectedly raised an error: RealityFoundation.CustomMaterialError.defaultSurfaceShaderForMaterialNotFound How can I apply a geometry modifier to a VideoMaterial? Or, if I can't do that, is there an easy way to route the AVPlayer video data into the baseColor of CustomMaterial?

Is it possible to start screen recording (through Control Center) without user prompt? I mean to ask user permission for the first time and after that to start and stop recording programmatically only? I need to record screen only for specific events.

Hi, I've got a Swift Framework with a bunch of Metal files. Currently users have to manually include a Metal Lib in their bundle provided separately, to use the Swift Package. First question; Is there a way to make a Metal Lib target in a Swift Package, and just include the .metal files? (without a binary asset) Second question; If not, Swift 5.3 has resource support, how would you recommend to bundle a Metal Lib in a Swift Package?