Transforming entities between RealityKit coordinate spaces

At a glance

Project structure

Source bundle/
├── CoordSpaceTransform/
│   ├── CoordSpaceTransformApp.swift
│   ├── AppModel.swift
│   ├── ImmersiveView.swift
│   ├── VolumetricView.swift
│   ├── ToggleImmersiveSpaceButton.swift
│   └── Info.plist
├── Configuration/
│   └── SampleCode.xcconfig
└── CoordSpaceTransform.xcodeproj/
    ├── .xcodesamplecode.plist
    └── project.pbxproj

Structure observations

• Architecturally prominent files are ranked from entry points and role-named declarations; resource-only paths are omitted.
• Primary languages: Swift.
• The verified tree contains 4 project/configuration file(s) and 6 source declaration(s).

Overall architecture

flowchart LR
    N1["CoordSpaceTransformApp"]
    N2["VolumetricView"]
    N3["AppModel"]
    N4["RealityKit APIs"]
    N1 --> N2
    N2 --> N3
    N3 --> N4

Reference code

CoordSpaceTransform/CoordSpaceTransformApp.swift:11 — architecture anchor

@main
struct CoordSpaceTransformApp: App {
    /// The app's observable data model.
    @State private var appModel = AppModel()

    /// The action that dismisses an immersive space.
    @Environment(\.dismissImmersiveSpace) private var dismissImmersiveSpace

    /// The action that presents an immersive space.
    @Environment(\.openImmersiveSpace) private var openImmersiveSpace

    var body: some Scene {
        WindowGroup(id: "VolumetricView") {
            VolumetricView()
                .environment(appModel)
        }
        .windowStyle(.volumetric)
        .defaultSize(width: 1.0, height: 1.0, depth: 1.0, in: .meters)

        ImmersiveSpace(id: "ImmersiveSpace") {
            ImmersiveView()
                .environment(appModel)
                .preferredSurroundingsEffect(.dark)
        }
    }
}

Interpretation

The arrows summarize the source-visible entry, role-named types or folders, and framework direction; when nodes come from structural folders, the sequence is a high-level interpretation rather than proof that every adjacent node calls the next. Ownership is claimed only where the next section cites a stored property or assignment. The diagram is intentionally limited to the dominant path into RealityKit.

Ownership and state

classDiagram
    CoordSpaceTransformApp *-- AppModel : appModel
    AppModel *-- Entity : volumeCube
    AppModel *-- Entity : volumeCubeLastSceneTransformEntity
    AppModel *-- Entity : volumeRootEntity

Ownership evidence

CoordSpaceTransform/CoordSpaceTransformApp.swift:14 — stored dependency or nearest verified ownership anchor

@main
struct CoordSpaceTransformApp: App {
    // ...
    @State private var appModel = AppModel()
    // ...
}

Composition arrows indicate a source-visible construction expression or locally owned value state; aggregation means the owner stores or receives a dependency without proving exclusive lifetime ownership.

Concurrency, scheduling, and thread safety

Evidence limit: actor isolation, async/await, or Task creation does not by itself prove background-thread execution; Sendable conformance alone does not prove thread-safe mutation.

@MainActor/MainActor.run, DispatchQueue.main, and RunLoop.main are reported as distinct isolation, queue, and event-loop mechanisms. A plain Task is kept separate from Task.detached; neither is labeled as a background thread.

Reference code

CoordSpaceTransform/ToggleImmersiveSpaceButton.swift:18 — representative execution boundary

            Task { @MainActor in
                // ...
                    case .open:
                // ...
            }

State propagation, frameworks, and dependencies

Evidence limit: an import proves a source-level compilation dependency at the cited line; it does not prove runtime use, architectural adoption, or whether a Swift package is a direct application dependency.

receive(on:) describes downstream delivery scheduling, while subscribe(on:) describes upstream subscription/request/cancel scheduling. An import Combine alone establishes neither behavior nor a Store, reducer, Redux, or other application architecture.

Class and protocol design

CoordSpaceTransform/CoordSpaceTransformApp.swift:12 — representative type boundary

@main
struct CoordSpaceTransformApp: App {
    // ...
    @State private var appModel = AppModel()
    // ...
}

No local protocol conformance is claimed as protocol-oriented design; external framework conformances are listed only as dependencies.

Access control

Reference code

CoordSpaceTransform/CoordSpaceTransformApp.swift:14 — representative boundary

@main
struct CoordSpaceTransformApp: App {
    // ...
    @State private var appModel = AppModel()
    // ...
}

Swift declarations without a modifier are internal; explicit private, fileprivate, private(set), public, or open entries above are interpreted by language semantics. Objective-C/C samples instead rely on header and implementation boundaries, which are not equivalent to Swift lexical privacy.

Logic ownership and placement

Design patterns

Naming conventions

• Types: App: CoordSpaceTransformApp; Model: AppModel; View: ImmersiveView, VolumetricView.
• Protocols: no local protocol declaration in the scanned source.
• Methods: updateTransformsWhileDragging, updateTransform, moveCubeFromImmersiveSpaceToVolumetricWindow, getDurationBasedOnDistance, makeCubeSubEntityOfVolumeRoot, createImmersiveSpaceRealityView, onMoveCompleted, createContentAndPositionAttachments.
• Files: CoordSpaceTransform/CoordSpaceTransformApp.swift, CoordSpaceTransform/AppModel.swift, CoordSpaceTransform/ImmersiveView.swift, CoordSpaceTransform/VolumetricView.swift, CoordSpaceTransform/ToggleImmersiveSpaceButton.swift.

Architecture takeaways

• CoordSpaceTransformApp is the main source-visible entry or composition anchor for this sample.
• Framework work reaches SwiftUI, RealityKit through a deliberately small high-level chain; the detailed API graph remains inside the cited implementation files.
• Stored-property evidence identifies lifecycle collaboration; it does not by itself prove exclusive object ownership.
• Access-control conclusions separate verified language visibility from the likely design rationale.
• The source does not justify labeling the design protocol-oriented.

Source map

• Official Apple documentation