Sample CodevisionOSReviewed 2026-07-21View on Apple Developer

Incorporating real-world surroundings in an immersive experience

At a glance

Item Summary
Purpose Create an immersive experience by making your app’s content respond to the local shape of the world.
App architecture A Swift sample with the source-visible chain SceneReconstructionExampleAppEntityModelARKit / RealityKit APIs.
Main patterns No named application pattern supported by the extracted structure
Project style 4 scanned source file(s) across Swift, organized around ranked entry, type, and file boundaries.
Execution model Source-visible boundaries: await suspension point, @MainActor; none alone proves a background thread.
State/event model Source-visible mechanisms: SwiftUI state property wrapper, @Observable.
Key frameworks/packages ARKit, RealityKit, SwiftUI, OSLog; these are source dependencies, not architecture labels.

Project structure

Source bundle/
├── SceneReconstructionExample/
│   ├── SceneReconstructionExampleApp.swift
│   ├── EntityModel.swift
│   ├── CubeMeshInteraction.swift
│   ├── Extensions.swift
│   └── Info.plist
├── Configuration/
│   └── SampleCode.xcconfig
└── SceneReconstructionExample.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 3 source declaration(s).

Overall architecture

Reference code

SceneReconstructionExample/SceneReconstructionExampleApp.swift:12 — architecture anchor

@main
struct SceneReconstructionExampleApp: App {
    @State private var model = EntityModel()

    var body: some Scene {
        ImmersiveSpace(id: cubeMeshInteractionID) {
            CubeMeshInteraction()
                .environment(model)
        }
    }
}

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

Ownership evidence

SceneReconstructionExample/SceneReconstructionExampleApp.swift:14 — stored dependency or nearest verified ownership anchor

@main
struct SceneReconstructionExampleApp: App {
    @State private var model = EntityModel()
    // ...
}
Owner Object or state Relationship Mutation authority
SceneReconstructionExampleApp EntityModel (model) owns wrapper-managed state Owning lexical scope
SceneReconstructionExampleApp Logger (logger) creates and retains Initialized by the owner; the binding is immutable
EntityModel ARKitSession (session) creates and retains Initialized by the owner; the binding is immutable
EntityModel HandTrackingProvider (handTracking) creates and retains Initialized by the owner; the binding is immutable

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.

Concern Source mechanism Verified placement or handoff Evidence
Suspension boundary await suspension point The source declares or crosses an asynchronous boundary; it does not by itself establish background execution. SceneReconstructionExample/CubeMeshInteraction.swift:46
Main isolation @MainActor The cited annotation marks its attached declaration or closure as main-actor isolated. SceneReconstructionExample/EntityModel.swift:13

@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

SceneReconstructionExample/CubeMeshInteraction.swift:46 — representative execution boundary

struct CubeMeshInteraction: View {
    // ...
                        try await model.session.run([model.sceneReconstruction, model.handTracking])
    // ...
}

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.

Category Mechanism or module Verified role Evidence
State propagation SwiftUI state property wrapper A SwiftUI property wrapper supplies or observes UI state. SceneReconstructionExample/CubeMeshInteraction.swift:18
State propagation @Observable Observation macro publishes source-visible changes. SceneReconstructionExample/EntityModel.swift:12
Source import ARKit The cited file imports this module; runtime use and architectural role are not inferred. SceneReconstructionExample/CubeMeshInteraction.swift:8
Source import RealityKit The cited file imports this module; runtime use and architectural role are not inferred. SceneReconstructionExample/CubeMeshInteraction.swift:10
Source import SwiftUI The cited file imports this module; runtime use and architectural role are not inferred. SceneReconstructionExample/CubeMeshInteraction.swift:9
Source import OSLog The cited file imports this module; runtime use and architectural role are not inferred. SceneReconstructionExample/SceneReconstructionExampleApp.swift:8

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

SceneReconstructionExample/SceneReconstructionExampleApp.swift:13 — representative type boundary

@main
struct SceneReconstructionExampleApp: App {
    @State private var model = EntityModel()
    // ...
}
Type Responsibility Depends on or conforms to
SceneReconstructionExampleApp Application entry and top-level composition App
EntityModel Feature data or observable state Concrete collaborators/imported frameworks
CubeMeshInteraction Represents a feature value or composable behavior View

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

Access control

Symbol Access Verified effect Likely rationale
meshEntities (SceneReconstructionExample/EntityModel.swift:21) private Use is restricted to the lexical declaration and same-file extensions allowed by Swift. Inference: keep state mutation or dependency lifetime inside the owning implementation.
fingerEntities (SceneReconstructionExample/EntityModel.swift:22) private Use is restricted to the lexical declaration and same-file extensions allowed by Swift. Inference: keep state mutation or dependency lifetime inside the owning implementation.
model (SceneReconstructionExample/SceneReconstructionExampleApp.swift:14) private Use is restricted to the lexical declaration and same-file extensions allowed by Swift. Inference: keep state mutation or dependency lifetime inside the owning implementation.

Reference code

SceneReconstructionExample/EntityModel.swift:21 — representative boundary

@Observable
@MainActor
class EntityModel {
    // ...
    private var meshEntities = [UUID: ModelEntity]()
    // ...
}

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

Logic Owning type or file Placement rationale
Application entry and top-level composition SceneReconstructionExampleApp The source’s App suffix makes this role explicit.
Feature data or observable state EntityModel The source’s Model suffix makes this role explicit.

Design patterns

Pattern Source evidence Purpose or tradeoff
No named application pattern SceneReconstructionExample/SceneReconstructionExampleApp.swift:12 The verified source directly composes concrete framework types; this document avoids forcing a pattern name.

Naming conventions

  • Types: App: SceneReconstructionExampleApp; Model: EntityModel.
  • Protocols: no local protocol declaration in the scanned source.
  • Methods: setupContentEntity, processHandUpdates, processReconstructionUpdates, monitorSessionEvents, addCube, createFingertip.
  • Files: SceneReconstructionExample/SceneReconstructionExampleApp.swift, SceneReconstructionExample/EntityModel.swift, SceneReconstructionExample/CubeMeshInteraction.swift.

Architecture takeaways

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

Source file Relevant symbols
SceneReconstructionExample/SceneReconstructionExampleApp.swift Cited implementation, SceneReconstructionExampleApp, OSLog
SceneReconstructionExample/EntityModel.swift Cited implementation, @MainActor, @Observable, EntityModel
SceneReconstructionExample/CubeMeshInteraction.swift await suspension point, SwiftUI state property wrapper, ARKit, RealityKit, SwiftUI, CubeMeshInteraction
SceneReconstructionExample/Extensions.swift func