Obscuring virtual items in a scene behind real-world items

At a glance

Project structure

Source bundle/
├── Occlusion/
│   ├── App/
│   │   ├── EntryPoint.swift
│   │   └── Info.plist
│   ├── Generators/
│   │   └── MeshAnchorGenerator.swift
│   ├── Views/
│   │   ├── MainView.swift
│   │   └── WorldOcclusionView.swift
│   └── Extensions/
│       └── SIMD3.swift
├── Configuration/
│   └── SampleCode.xcconfig
└── Occlusion.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 4 source declaration(s).

Overall architecture

flowchart LR
    N1["EntryPoint"]
    N2["MainView"]
    N3["MeshAnchorGenerator"]
    N4["SwiftUI / ARKit APIs"]
    N1 --> N2
    N2 --> N3
    N3 --> N4

Reference code

Occlusion/App/EntryPoint.swift:10 — architecture anchor

@main
struct EntryPoint: App {
    // ...
        WindowGroup {
            MainView()
        }
    // ...
}

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 visionOS.

Ownership and state

classDiagram
    MeshAnchorGenerator o-- Entity : root
    MeshAnchorGenerator *-- Dictionary : anchors
    WorldOcclusionView *-- SIMD3 : initialPosition

Ownership evidence

Occlusion/Generators/MeshAnchorGenerator.swift:16 — stored dependency or nearest verified ownership anchor

class MeshAnchorGenerator {
    // ...
    var root: Entity?
    // ...
}

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

Occlusion/Generators/MeshAnchorGenerator.swift:26 — representative execution boundary

    @MainActor
    func run(_ sceneRec: SceneReconstructionProvider) async {
        // ...
            case .added, .updated:
        // ...
    }

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

Occlusion/Generators/MeshAnchorGenerator.swift:14 — representative type boundary

class MeshAnchorGenerator {
    // ...
    var root: Entity?
    // ...
}

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

Access control

Reference code

Occlusion/Generators/MeshAnchorGenerator.swift:19 — representative boundary

class MeshAnchorGenerator {
    // ...
    private var anchors: [UUID: Entity] = [:]
    // ...
}

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: Generator: MeshAnchorGenerator; View: MainView, WorldOcclusionView.
• Protocols: no local protocol declaration in the scanned source.
• Methods: run, runSession.
• Files: Occlusion/App/EntryPoint.swift, Occlusion/Generators/MeshAnchorGenerator.swift, Occlusion/Views/MainView.swift, Occlusion/Views/WorldOcclusionView.swift.

Architecture takeaways

• EntryPoint is the main source-visible entry or composition anchor for this sample.
• Framework work reaches SwiftUI, ARKit, 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