Sample CodevisionOSReviewed 2026-07-21View on Apple Developer

Creating 3D models as movable windows

At a glance

Item Summary
Purpose Display 3D content with a volumetric window that people can move.
App architecture A Swift sample whose EntryPoint entry flows through VolumetricWindow before reaching SwiftUI / RealityKit APIs.
Main patterns No named application pattern supported by the extracted structure
Project style 2 scanned source file(s) across Swift, organized around ranked entry, type, and file boundaries.
Execution model Source-visible boundaries: await suspension point; none alone proves a background thread.
State/event model No structured observation or publisher-scheduling marker indexed.
Key frameworks/packages SwiftUI, RealityKit; these are source dependencies, not architecture labels.

Project structure

Source bundle/
├── Creating a Volumetric Window/
│   ├── App/
│   │   ├── EntryPoint.swift
│   │   └── Info.plist
│   └── Views/
│       └── VolumetricWindow.swift
├── Configuration/
│   └── SampleCode.xcconfig
└── Creating a Volumetric Window.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 2 source declaration(s).

Overall architecture

Reference code

Creating a Volumetric Window/App/EntryPoint.swift:10 — architecture anchor

@main
struct EntryPoint: App {
    /// The multiplier for the height of the volumetric window.
    let heightModifier: CGFloat = 0.25

    var body: some Scene {
        // Configure a window group with a volumetric window.
        WindowGroup() {
            VolumetricWindow()
        }
        .windowStyle(.volumetric)
        // Scale the size of the window group relative to the volumetric window's size.
        .defaultSize(
            width: VolumetricWindow.defaultSize,
            height: heightModifier * VolumetricWindow.defaultSize,
            depth: VolumetricWindow.defaultSize,
            in: .meters
        )
    }
}

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

Creating a Volumetric Window/App/EntryPoint.swift:13 — stored dependency or nearest verified ownership anchor

@main
struct EntryPoint: App {
    // ...
    let heightModifier: CGFloat = 0.25
    // ...
}
Owner Object or state Relationship Mutation authority
EntryPoint CGFloat (heightModifier) owns value state Initialized by the owner; the binding is immutable
VolumetricWindow CGFloat (defaultSize) owns value state Initialized by the owner; the binding is immutable
VolumetricWindow String (modelName) owns value state 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. Creating a Volumetric Window/Views/VolumetricWindow.swift:25

@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

Creating a Volumetric Window/Views/VolumetricWindow.swift:25 — representative execution boundary

                guard let model = try? await ModelEntity(named: modelName) else {
                    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
Source import SwiftUI The cited file imports this module; runtime use and architectural role are not inferred. Creating a Volumetric Window/App/EntryPoint.swift:8
Source import RealityKit The cited file imports this module; runtime use and architectural role are not inferred. Creating a Volumetric Window/Views/VolumetricWindow.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

Creating a Volumetric Window/App/EntryPoint.swift:11 — representative type boundary

@main
struct EntryPoint: App {
    // ...
    let heightModifier: CGFloat = 0.25
    // ...
}
Type Responsibility Depends on or conforms to
EntryPoint Represents a feature value or composable behavior App
VolumetricWindow 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
EntryPoint (Creating a Volumetric Window/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.
VolumetricWindow (Creating a Volumetric Window/Views/VolumetricWindow.swift:12) 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

Creating a Volumetric Window/App/EntryPoint.swift:11 — representative boundary

@main
struct EntryPoint: App {
    // ...
    let heightModifier: CGFloat = 0.25
    // ...
}

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
Presentation VolumetricWindow Folder and filename roles place this logic at Creating a Volumetric Window/Views/VolumetricWindow.swift.

Design patterns

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

Naming conventions

  • Types: feature-specific names rather than reusable layer suffixes.
  • Protocols: no local protocol declaration in the scanned source.
  • Methods: no representative method name extracted from the architectural files.
  • Files: Creating a Volumetric Window/App/EntryPoint.swift, Creating a Volumetric Window/Views/VolumetricWindow.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
Creating a Volumetric Window/App/EntryPoint.swift Cited implementation, EntryPoint, SwiftUI
Creating a Volumetric Window/Views/VolumetricWindow.swift VolumetricWindow, await suspension point, RealityKit