Creating an immersive ar experience with audio
At a glance
| Item | Summary |
|---|---|
| Purpose | Use sound effects and environmental sound layers to create an engaging AR experience. |
| App architecture | A Swift sample with the source-visible chain AppDelegate → ViewController → ARKit APIs. |
| Main patterns | View-controller organization, Delegate or data-source callbacks |
| Project style | 5 scanned source file(s) across Swift, organized around ranked entry, type, and file boundaries. |
Project structure
Source bundle/
├── Audio in ARKit/
│ ├── AppDelegate.swift
│ ├── ViewController.swift
│ ├── PreviewNode.swift
│ ├── ARSCNView+Raycasts.swift
│ ├── Utilities.swift
│ └── Resources/
│ ├── Base.lproj/
│ │ ├── LaunchScreen.storyboard
│ │ └── Main.storyboard
│ └── Info.plist
├── Audio in ARKit.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 6 project/configuration file(s) and 3 source declaration(s).
Overall architecture
flowchart LR
N1["AppDelegate"]
N2["ViewController"]
N3["ARKit APIs"]
N1 --> N2
N2 --> N3
Reference code
Audio in ARKit/AppDelegate.swift:11 — architecture anchor
@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
// ...
}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 ARKit.
Ownership and state
classDiagram
AppDelegate o-- UIWindow : window
ViewController o-- UIView : sessionInfoView
ViewController o-- UILabel : sessionInfoLabel
ViewController o-- ARSCNView : sceneView
Ownership evidence
Audio in ARKit/AppDelegate.swift:13 — stored dependency or nearest verified ownership anchor
@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
var window: UIWindow?
// ...
}| Owner | Object or state | Relationship | Mutation authority |
|---|---|---|---|
AppDelegate |
UIWindow (window) |
stores or receives | App/module collaborators |
ViewController |
UIView (sessionInfoView) |
holds a non-owning reference | The referenced object’s lifecycle is owned elsewhere |
ViewController |
UILabel (sessionInfoLabel) |
holds a non-owning reference | The referenced object’s lifecycle is owned elsewhere |
ViewController |
ARSCNView (sceneView) |
holds a non-owning reference | The referenced object’s lifecycle is owned elsewhere |
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.
Class and protocol design
Audio in ARKit/AppDelegate.swift:12 — representative type boundary
class AppDelegate: UIResponder, UIApplicationDelegate {
// ...
}| Type | Responsibility | Depends on or conforms to |
|---|---|---|
AppDelegate |
Receives callback-driven events | UIResponder, UIApplicationDelegate |
ViewController |
View lifecycle, callbacks, and feature coordination | UIViewController, ARSCNViewDelegate |
PreviewNode |
Owns feature behavior and collaborator lifecycle | SCNNode |
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 |
|---|---|---|---|
distanceToCamera (Audio in ARKit/ARSCNView+Raycasts.swift:91) |
private |
Use is restricted to the lexical declaration and same-file extensions allowed by Swift. | Inference: hide an implementation step that is not part of the collaboration surface. |
recentPreviewNodePositions (Audio in ARKit/PreviewNode.swift:18) |
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. |
updateTransform (Audio in ARKit/PreviewNode.swift:48) |
private |
Use is restricted to the lexical declaration and same-file extensions allowed by Swift. | Inference: hide an implementation step that is not part of the collaboration surface. |
setUpCamera (Audio in ARKit/ViewController.swift:93) |
private |
Use is restricted to the lexical declaration and same-file extensions allowed by Swift. | Inference: hide an implementation step that is not part of the collaboration surface. |
Reference code
Audio in ARKit/ARSCNView+Raycasts.swift:91 — representative boundary
private func distanceToCamera(_ result: ARRaycastResult) -> Float {
// ...
}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 |
|---|---|---|
| View lifecycle, callbacks, and feature coordination | ViewController |
The source’s Controller suffix makes this role explicit. |
| Receives callback-driven events | AppDelegate |
The source’s Delegate suffix makes this role explicit. |
Design patterns
| Pattern | Source evidence | Purpose or tradeoff |
|---|---|---|
| View-controller organization | Audio in ARKit/ViewController.swift:12 |
A controller is the verified coordination boundary; this is MVC-style only where a separate model is present. |
| Delegate or data-source callbacks | Audio in ARKit/AppDelegate.swift:12 |
Callback protocols invert event delivery back into the sample’s owner. |
Naming conventions
- Types: Controller: ViewController; Delegate: AppDelegate.
- Protocols: no local protocol declaration in the scanned source.
- Methods:
applicationDidFinishLaunching,viewDidLoad,viewWillAppear,viewWillDisappear,viewWillTransition,setUpCamera,resetTracking,beginRelocalization. - Files:
Audio in ARKit/AppDelegate.swift,Audio in ARKit/ViewController.swift,Audio in ARKit/PreviewNode.swift.
Architecture takeaways
AppDelegateis the main source-visible entry or composition anchor for this sample.- Framework work reaches ARKit, UIKit, SceneKit 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 |
|---|---|
Audio in ARKit/AppDelegate.swift |
AppDelegate |
Audio in ARKit/ViewController.swift |
ViewController |
Audio in ARKit/PreviewNode.swift |
PreviewNode |
Audio in ARKit/ARSCNView+Raycasts.swift |
Feature implementation |
Audio in ARKit/Utilities.swift |
Feature implementation |