v26.5.2 | OpenUSDKit & HydraKit

_{SwiftUSD v26.5.2}

^{OpenUSDKit & HydraKit}

Changelog

Changes

• Introducing OpenUSDKit, a unified cross-platform Swift API for OpenUSD. It is a direct replacement for the PixarUSD target.
• Introducing HydraKit, a composable Hydra viewport with SwiftCrossUI:

  import Foundation
  import OpenUSDKit
  import HydraKit
  import SwiftCrossUI
  
  @main
  struct MyApp: App {
    typealias Backend = PlatformBackend
  
    let stage: UsdStage
    let engine: Hydra.RenderEngine
  
    init() {
      Pixar.Bundler.shared.setup(.resources)
  
      stage = UsdStage.createInMemory()
      engine = Hydra.RenderEngine(stage: stage)
    }
    
    var body: some Scene {
      WindowGroup("MyApp") {
        Hydra.Viewport(engine: engine)
      }
    }
  }

  import SwiftCrossUI
    
  // Platform backend selection is explicit for now, this will eventually just end up
  // in HydraKit to handle this by default, but figured it was worth showing what is
  // going on under the hood, if developers wish to make extensible backends for
  // their own apps.
  #if os(Android)
    import AndroidBackend
    public typealias PlatformBackend = AndroidBackend
  #elseif os(Linux)
    import GtkBackend
    public typealias PlatformBackend = GtkBackend
  #elseif os(Windows)
    import WinUIBackend
    public typealias PlatformBackend = WinUIBackend
  #elseif os(macOS)
    import AppKitBackend
    public typealias PlatformBackend = AppKitBackend
  #else
    import UIKitBackend
    public typealias PlatformBackend = UIKitBackend
  #endif

• Integrates apple/SwiftUsd within OpenUSDKit and brings precompiled binaries for Darwin platforms by default, use the environment variable SWIFTUSD_BUILD_FROM_SOURCE=1 if you prefer to build from source and match the behavior on all other platforms (Android, Linux, and Microsoft Windows).
• Adds the availability of zero-copy VtArray reads, and single-copy VtArray writes from a contiguous buffer in Swift.
• Adds the availability of some OpenExec types to Swift:

  import OpenUSDKit
  
  let stage = UsdStage.createInMemory()
  let system = ExecUsdSystem.create(stage: stage)
  
  UsdGeom.Xform.define(stage, path: "/hello")
  let prim = UsdGeom.Sphere.define(stage, path: "/hello/world")
  
  let key = Pixar.ExecUsdValueKey(prim, .init("computeLocalToWorldTransform"))
  let request = system.BuildRequest(consuming: [key])
  let view = system.Compute(request)
  
  var val = view.Get(0)
  if val.IsHolding(T: pxr.GfMatrix4d.self) {
    let matrix: pxr.GfMatrix4d = val.UncheckedGet()
  }

• Adds the latest changes from upstream PixarAnimationStudios/OpenUSD's dev branch, up to commit 3e38900 (the latest revision at the time of writing).

---

🎧 now playing
listen to la baleine et le musicien by rone.

---

Thank you

• @meshula
• @dgovil
• @brechtvl
• @stackotter
• @gracien-app
• @scott-wilson
• @obvgab
• @felfoldy
• Pixar's OpenUSD contributors

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Usage

To use this release of USD in your swift project, add the following to the dependencies section in your Package.swift file:

// swift-tools-version: 6.1

dependencies: [
  .package(url: "https://github.com/wabiverse/swift-usd.git", from: "26.5.2")
]

Linux

For Linux, these are the only dependencies required, as MetaverseKit provides everything else.

Tip

If you are on a distro like Ubuntu there is a good chance you already have most of these installed.

Dependency	CentOS	Ubuntu
BZ2	bzip2-devel	libbz2-dev
ZLib	zlib-devel	zlib1g-dev
FreeGLUT	freeglut-devel	freeglut3-dev
DEFLATE	libdeflate-devel	libdeflate-dev
Expat	libexpat-devel	libexpat1-dev
Xcursor	libXcursor-devel	libxcursor-dev
Xt	libXt-devel	libxt-dev
Xi	libXi-devel	libxi-dev
Xinerama	libXinerama-devel	libxinerama-dev
Xrandr	libXrandr-devel	libxrandr-dev