Designing no-code games with Reality Composer Pro 3

At a glance

Project structure

Source bundle/
├── Squirrel/
│   ├── SquirrelApp.swift
│   ├── DinnerBubbleView.swift
│   ├── ContentView.swift
│   ├── SquirrelTalkAttachmentView.swift
│   ├── ContentViewAttachments.swift
│   └── UIPreview.swift
├── Configuration/
│   ├── EmbedFrameworks.sh
│   ├── ExportRealityFiles.sh
│   ├── InstallPlugin.sh
│   ├── AppConfig.xcconfig
│   └── SampleCode.xcconfig
└── Squirrel.xcodeproj/
    └── .xcodesamplecode.plist

Structure observations

• Architecturally prominent files are ranked from entry points and role-named declarations; resource-only paths are omitted.
• Primary languages: Shell, Swift.
• The verified tree contains 5 project/configuration file(s) and 8 source declaration(s).

Overall architecture

flowchart LR
    N1["SquirrelApp"]
    N2["ContentView"]
    N3["SwiftUI / RealityKit APIs"]
    N1 --> N2
    N2 --> N3

Reference code

Squirrel/SquirrelApp.swift:18 — architecture anchor

@main
struct SquirrelApp: App {

    init() {
        do {
            // Initialize the Script Graph runtime before any RealityView loads
            // a scene that contains `ScriptingComponent`s. `.subtracting(.ar)`
            // disables AR input because this sample runs in a volumetric window.
            try RKS.initialize(inputOptions: .all.subtracting(.ar))
        } catch {
            assertionFailure("Failed to initialize the Script Graph runtime: \(error)")
        }
    }

    var body: some SwiftUI.Scene {
        WindowGroup {
            ContentView()
        }
        #if os(visionOS)
            .windowStyle(.volumetric)
            .defaultSize(width: 1.8, height: 1.8, depth: 1.2, in: .meters)
        #endif
    }
}

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
    SquirrelApp *-- Logger : logger
    TreeTalkAttachmentView *-- Bool : isVisible
    TreeTalkAttachmentView *-- String : text
    SpeechBubbleShape *-- CGFloat : insetAmount

Ownership evidence

Squirrel/SquirrelApp.swift:15 — stored dependency or nearest verified ownership anchor

let logger = Logger(subsystem: "com.example.apple-samplecode.Squirrel", category: "Squirrel")

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

Squirrel/ContentView.swift:42 — representative execution boundary

struct ContentView: View {
    // ...
                let entity = (try await Entity(named: "world"))
    // ...
}

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

Squirrel/SquirrelApp.swift:19 — representative type boundary

@main
struct SquirrelApp: App {
    // ...
            try RKS.initialize(inputOptions: .all.subtracting(.ar))
    // ...
}

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

Access control

Reference code

Squirrel/ContentView.swift:291 — representative boundary

    private func sendSceneEvent(eventName: String) {
        guard let scene = self.scene?.scene else {
            return
        }
        scene.send(name: eventName)
    }

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: SquirrelApp; View: ContentView, SquirrelTalkAttachmentView, TreeTalkAttachmentView.
• Protocols: no local protocol declaration in the scanned source.
• Methods: inset, path, addCorner, sendSceneEvent, jumpToScene, formatPlayTime, scriptingEntity.
• Files: Squirrel/SquirrelApp.swift, Squirrel/ContentView.swift, Squirrel/SquirrelTalkAttachmentView.swift.

Architecture takeaways

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