Sample CodevisionOSReviewed 2026-07-21View on Apple Developer

Creating an interactive 3D model in visionOS

At a glance

Item Summary
Purpose Display an interactive car model using gestures in a reality view.
App architecture A Swift sample with the source-visible chain EntryPointMainViewSwiftUI / 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, Task; none alone proves a background thread.
State/event model Source-visible mechanisms: SwiftUI state property wrapper.
Key frameworks/packages SwiftUI, RealityKit; these are source dependencies, not architecture labels.

Project structure

Source bundle/
├── CarExample/
│   ├── App/
│   │   ├── EntryPoint.swift
│   │   └── Info.plist
│   ├── Views/
│   │   ├── CarView.swift
│   │   └── MainView.swift
│   └── Extensions/
│       └── SIMD3.swift
├── CarExample.xcodeproj/
│   ├── .xcodesamplecode.plist
│   └── project.pbxproj
└── Configuration/
    └── SampleCode.xcconfig

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

CarExample/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

Ownership evidence

CarExample/Views/CarView.swift:15 — stored dependency or nearest verified ownership anchor

struct CarView: View {
    // ...
    @State var initialPosition: SIMD3<Float>? = nil
    // ...
}
Owner Object or state Relationship Mutation authority
CarView SIMD3 (initialPosition) owns wrapper-managed state App/module collaborators
CarView SIMD3 (initialScale) owns wrapper-managed state App/module collaborators

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. CarExample/Views/CarView.swift:80
Task creation Task The source creates an unstructured task; surrounding context determines inherited actor isolation. CarExample/Views/MainView.swift:19

@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

CarExample/Views/CarView.swift:80 — representative execution boundary

            guard let car = try? await ModelEntity(named: fileName) else {
                assertionFailure("Failed to load model: \(fileName)")
                return
            }

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. CarExample/Views/CarView.swift:15
Source import SwiftUI The cited file imports this module; runtime use and architectural role are not inferred. CarExample/App/EntryPoint.swift:8
Source import RealityKit The cited file imports this module; runtime use and architectural role are not inferred. CarExample/Views/CarView.swift:9

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

CarExample/Views/CarView.swift:13 — representative type boundary

struct CarView: View {
    // ...
    @State var initialPosition: SIMD3<Float>? = nil
    // ...
}
Type Responsibility Depends on or conforms to
CarView User-interface presentation and input forwarding View
MainView User-interface presentation and input forwarding View
EntryPoint Represents a feature value or composable behavior App

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
CarView (CarExample/Views/CarView.swift:13) implicit internal No explicit modifier means the Swift declaration is internal to the module. Inference: app-target collaboration needs no exported library surface.
MainView (CarExample/Views/MainView.swift:10) implicit internal No explicit modifier means the Swift declaration is internal to the module. Inference: app-target collaboration needs no exported library surface.
EntryPoint (CarExample/App/EntryPoint.swift:11) implicit internal No explicit modifier means the Swift declaration is internal to the module. Inference: app-target collaboration needs no exported library surface.

Reference code

CarExample/Views/CarView.swift:13 — representative boundary

struct CarView: View {
    // ...
    @State var initialPosition: SIMD3<Float>? = nil
    // ...
}

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
User-interface presentation and input forwarding CarView, MainView The source’s View suffix makes this role explicit.

Design patterns

Pattern Source evidence Purpose or tradeoff
No named application pattern CarExample/App/EntryPoint.swift:10 The verified source directly composes concrete framework types; this document avoids forcing a pattern name.

Naming conventions

  • Types: View: CarView, MainView.
  • Protocols: no local protocol declaration in the scanned source.
  • Methods: no representative method name extracted from the architectural files.
  • Files: CarExample/App/EntryPoint.swift, CarExample/Views/CarView.swift, CarExample/Views/MainView.swift.

Architecture takeaways

  • EntryPoint 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

Source file Relevant symbols
CarExample/App/EntryPoint.swift Cited implementation, EntryPoint, SwiftUI
CarExample/Views/CarView.swift Cited implementation, CarView, await suspension point, SwiftUI state property wrapper, RealityKit
CarExample/Views/MainView.swift MainView, Task
CarExample/Extensions/SIMD3.swift Feature implementation