Pixar's universal scene description for swift and the open source metaverse.

Important

Supporting SwiftUSD ❤️

If you find SwiftUSD useful, please consider supporting me by becoming a sponsor. I spend a tremendous amount of time dedicating my life to open source projects, and each sponsorship helps me focus more time on making quality tools and software for the community.

Swifting the Metaverse

Universal Scene Description (USD) is an efficient, scalable system for authoring, reading, and streaming time-sampled scene description for interchange between graphics applications.

For more details, please visit the web site here.

To use Pixar's USD in swift, add SwiftUSD as a package dependency in your project's Package.swift file.

dependencies: [
  .package(url: "https://github.com/wabiverse/SwiftUSD.git", from: "24.8.12"),
]

Then, for any target you'd like, add the monolithic USD Pixar product as a target dependency, a complete example.

// swift-tools-version: 5.10
import PackageDescription

let package = Package(
  name: "MyMetaversePackage",
  platforms: [
    .macOS(.v14),
    .visionOS(.v1),
    .iOS(.v17),
    .tvOS(.v17),
    .watchOS(.v10)
  ],
  // --- 📦 Package Products. ---
  products: [
    .library(
      name: "MyMetaverseLibrary",
      targets: ["MyMetaverseLibrary"]
    ),
    .executable(
      name: "MyMetaverseApp",
      targets: ["MyMetaverseApp"]
    ),
  ],
  dependencies: [
    .package(url: "https://github.com/wabiverse/SwiftUSD.git", from: "24.8.12")
  ],
  targets: [
    /* 📕 For library products... */
    .target(
      name: "MyMetaverseLibrary",
      dependencies: [
        /* add pixar usd as a library dependency. */
        .product(name: "PixarUSD", package: "SwiftUSD"),
      ],
      cxxSettings: [
        /* for windows support, add these three defines until swift's clang is updated. */
        .define("_ALLOW_COMPILER_AND_STL_VERSION_MISMATCH", .when(platforms: [.windows])),
        .define("_ALLOW_KEYWORD_MACROS", to: "1", .when(platforms: [.windows])),
        .define("static_assert(_conditional, ...)", to: "", .when(platforms: [.windows])),
      ],
      swiftSettings: [
        /* enable swift/c++ interop. */
        .interoperabilityMode(.Cxx)
      ]
    ),

    /* 📗 Or executable products... */
    .executableTarget(
      name: "MyMetaverseApp",
      dependencies: [
        /* add pixar usd as an executable dependency. */
        .product(name: "PixarUSD", package: "SwiftUSD"),
      ],
      cxxSettings: [
        /* for windows support, add these three defines until swift's clang is updated. */
        .define("_ALLOW_COMPILER_AND_STL_VERSION_MISMATCH", .when(platforms: [.windows])),
        .define("_ALLOW_KEYWORD_MACROS", to: "1", .when(platforms: [.windows])),
        .define("static_assert(_conditional, ...)", to: "", .when(platforms: [.windows])),
      ],
      swiftSettings: [
        /* enable swift/c++ interop. */
        .interoperabilityMode(.Cxx)
      ],
      plugins: [
        /* 📙 And, plugins are added like so. */
        .plugin(name: "UsdGenSchemaPlugin", package: "SwiftUSD")
      ]
    ),
  ],
  /* use cxx17 language standard. */
  cxxLanguageStandard: .cxx17
)

@@ Dependency Notes @@
- Library Products allow clients that declare a dependency on this package to use the package’s functionality.
+ Executable Products vend an executable target. Use this only if you want to make the executable available to clients.
! Plugin Products vend plugin targets. This makes the plugin available to clients that integrate the Swift package.
# Swift's package manager, SwiftPM, is capabable of building Swift, Objective-C/C++, and C/C++ code.

Finally, author scene description, this is a working example of creating a new USD stage with a transform and a sphere in swift.

import Foundation
import PixarUSD

@main
enum Creator
{
  static func main()
  {
    /* Setup all usd resources (python, plugins, resources). */

    Pixar.Bundler.shared.setup(.resources)

    /* Create a new USD stage with a transform and a sphere. */

    let stage = Usd.Stage.createNew("HelloPixarUSD.usda")

    UsdGeom.Xform.define(stage, path: "/Hello")
    UsdGeom.Sphere.define(stage, path: "/Hello/World")

    stage.getPseudoRoot().set(doc: "Hello World Example (Swift)!")

    stage.save()
  }
}

Or, if you prefer those swifty declarative APIs...

import Foundation
import PixarUSD

@main
enum Creator
{
  static func main()
  {
    /* Setup all usd resources (python, plugins, resources). */

    Pixar.Bundler.shared.setup(.resources)

    /* Create a new USD stage with a transform and a sphere. */

    USDStage("HelloPixarUSD", ext: .usda)
    {
      USDPrim("Hello", type: .xform)
      {
        USDPrim("World", type: .sphere)
      }
    }
    .set(doc: "Stay Swifty.")
    .save()
  }
}

UsdView (Under Development)

The UsdView application in this project is written entirely in Swift, and serves as a living example of both Swift/C++ interop and creating cross platform UI applications in Swift (utilizing SwiftCrossUI).

Linux

Important

The bundler is currently in development to support bundling apps on Linux, until then please follow these instructions to run UsdView on Linux:

git clone https://github.com/wabiverse/SwiftUSD
cd SwiftUSD

swift run -c release UsdView

Apple Devices (macOS, visionOS, iOS)

Tip

Install the bundler locally by running the following commands in your terminal:

git clone https://github.com/stackotter/swift-bundler
cd swift-bundler

swift build -c release
sudo cp .build/release/swift-bundler /usr/local/bin/

Finally, to run and bundle UsdView or any other app (such as your own!) with the bundler installed locally, run the following commands:

git clone https://github.com/wabiverse/SwiftUSD
cd SwiftUSD

macOS

Run and bundle UsdView on macOS.

swift bundler run -c release UsdView

visionOS or iOS

Run and bundle UsdView on visionOS or iOS.

# list available iOS and visionOS simulators.
swift bundler simulators

# boot a simulator from the list.
swift bundler simulators boot [id-of-device]

# if you booted a visionOS device.
swift bundler run -p visionOSSimulator -c release UsdView

# if you booted a iOS device.
swift bundler run -p iOSSimulator -c release UsdView

OH SH!

You can even run it in a tiny script, no package necessary, the comments next to the import statements describe the git sources to pull from, and everything transitively linked will come flying on in - checkout swift-sh!

Important

You will need to use the Wabi fork of swift-sh in order for this to work with Swift 5.9 cxx interop.

Note

Swift is an open source programming language that is fully supported across Linux and Swift on Server, the entire Apple family of devices: macOS, visionOS, iOS, tvOS, watchOS, as well as support for Microsoft Windows. To learn more about Swift, please visit swift.org.

---

if you can mmap a pixel, you can mmap a metaverse.

SwiftUSD is licensed under the terms of the Tomorrow Open Source Technology 1.0 License.