I'm trying to build an MDLMesh then add normals let mdlMesh = MDLMesh.newBox(withDimensions: SIMD3<Float>(1, 1, 1), segments: SIMD3<UInt32>(2, 2, 2), geometryType: MDLGeometryType.triangles, inwardNormals:false, allocator: allocator) mdlMesh.addNormals(withAttributeNamed: MDLVertexAttributeNormal, creaseThreshold: 0) When I render the mesh, some normals are (0,0,0). I don't know if the problem is in the mesh, or in the conversion to MTKMesh. Is there a way to examine an MDLMesh with the geometry viewer? When I look at the variable values for my mdlMesh I get this: Not too useful. I don't know how to track down the normals. What's the best way to find out where the normals getting broken?

I made a box with MDLMesh.newBox(). I added normals. let mdlMesh = MDLMesh.newBox(withDimensions: SIMD3<Float>(1, 1, 1), segments: SIMD3<UInt32>(2, 2, 2), geometryType: MDLGeometryType.triangles, inwardNormals:false, allocator: allocator) mdlMesh.addNormals(withAttributeNamed: MDLVertexAttributeNormal, creaseThreshold: 0.25) After I convert to MTKMesh the normals are (0,0,0) for a group of vertices. I can only inspect the geometry after I convert to MTKMesh. Is there a way you can use Geometry Viewer on a MDLMesh?

I'm try to use CoreHID to communicate with a usb hid device that sends custom reports. I have been able to create a client, but when I try to access the elements I get this: IOServiceOpen failed: 0xe00002e2 This looks like a low level error. I'm hoping someone in the community has seen it, maybe using IOKit and can point me to some information.

I'm try to use CoreHID to communicate with a usb hid device that sends custom reports. I have been able to create a client, but when I try to access the elements I get this: IOServiceOpen failed: 0xe00002e2 also in: client.monitorNotifications(reportIDsToMonitor: [HIDReportID.allReports], elementsToMonitor: []) {... What do I put into "elementsToMonitor: []" array?

Is there an easy(ier) way to work with skeleton tracking? I have an iPad on a stand and I am the model most of the time. I can't stand in front of the camera and see what's on the iPad. I don't think I can use the front camera for tracking. My wife is getting very tired of "Honey, can you come here a minute?" How is this supposed to work?

I've been watching a 2019 Developer Video "Building Apps with RealityKit" and working along with it. It shows how to create a custom entity. It shows how to load entities from .usd files. How do you either load a custom entity, convert an Entity to a custom entity, or maybe move model hierarchy from an Entity to a custom entity? I assume there's a way to do this.

I'm using playground to experiment with Combine. I found this example on a blog. I expect it to create the Future publisher, wait a couple seconds then send the promise and complete. import Foundation import Combine import SwiftUI let future = Future<Int, Never> { promise in     print("Creating")     DispatchQueue.global().asyncAfter(deadline: .now() + 2) {         print("sending promise")         promise(.success(1))     } } future     .sink(receiveCompletion: { print("receiveCompletion:\($0)") },             receiveValue: { print("receiveValue:\($0)") }) print("end") The output I expect: Creating end sending promise receiveValue: ... receiveCompletion: ... The output I get: Creating end sending promise I don't see an indication the promise was executed. What am I doing wrong?