Gaussian splats on visionOS
At a glance
| Item | Summary |
|---|---|
| Purpose | Use the new Gaussian splat APIs available in RealityKit in visionOS 27. |
| App architecture | A Swift sample with the source-visible chain GaussianSplatsOnVisionOSApp → ContentView → SplatViewCoordinator → RealityKit / SwiftUI APIs. |
| Main patterns | Coordinator |
| Project style | 9 scanned source file(s) across Swift, organized around ranked entry, type, and file boundaries. |
| Execution model | Source-visible boundaries: @MainActor, Task, await suspension point, Task.detached, Sendable or @Sendable; none alone proves a background thread. |
| State/event model | Source-visible mechanisms: @Observable, SwiftUI state property wrapper. |
| Key frameworks/packages | RealityKit, Foundation, SwiftUI, ARKit, os; these are source dependencies, not architecture labels. |
Project structure
Source bundle/
├── GaussianSplatsOnVisionOS/
│ ├── GaussianSplatsOnVisionOSApp.swift
│ ├── AppModel.swift
│ ├── SplatView.swift
│ ├── SplatEntityBuilder.swift
│ ├── ContentView.swift
│ ├── PLYParser.swift
│ ├── SceneReconstructionManager.swift
│ ├── USDLoader.swift
│ └── PLYLoader.swift
├── Configuration/
│ └── SampleCode.xcconfig
└── Gaussian-Splats-on-visionOS.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 16 source declaration(s).
Overall architecture
flowchart LR
N1["GaussianSplatsOnVisionOSApp"]
N2["ContentView"]
N3["SplatViewCoordinator"]
N4["RealityKit / SwiftUI APIs"]
N1 --> N2
N2 --> N3
N3 --> N4
Reference code
GaussianSplatsOnVisionOS/GaussianSplatsOnVisionOSApp.swift:10 — architecture anchor
@main
struct GaussianSplatsOnVisionOSApp: App {
@State private var appModel = AppModel()
var body: some Scene {
WindowGroup {
ContentView()
.environment(appModel)
}
.windowResizability(.contentSize)
ImmersiveSpace(id: appModel.immersiveSpaceId) {
SplatView()
.environment(appModel)
}
.immersionStyle(selection: .constant(.mixed), in: .mixed)
}
}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
GaussianSplatsOnVisionOSApp *-- AppModel : appModel
AppModel o-- ImmersiveSpaceState : immersiveSpaceState
AppModel o-- LoadedAsset : loadedAsset
SplatView *-- Logger : logger
Ownership evidence
GaussianSplatsOnVisionOS/GaussianSplatsOnVisionOSApp.swift:12 — stored dependency or nearest verified ownership anchor
@main
struct GaussianSplatsOnVisionOSApp: App {
@State private var appModel = AppModel()
// ...
}| Owner | Object or state | Relationship | Mutation authority |
|---|---|---|---|
GaussianSplatsOnVisionOSApp |
AppModel (appModel) |
owns wrapper-managed state | Owning lexical scope |
AppModel |
ImmersiveSpaceState (immersiveSpaceState) |
stores or receives | App/module collaborators |
AppModel |
LoadedAsset (loadedAsset) |
stores or receives | App/module collaborators |
SplatView |
Logger (logger) |
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 |
|---|---|---|---|
| Main isolation | @MainActor |
The cited annotation marks its attached declaration or closure as main-actor isolated. | GaussianSplatsOnVisionOS/AppModel.swift:11 |
| Task creation | Task |
The source creates an unstructured task; surrounding context determines inherited actor isolation. | GaussianSplatsOnVisionOS/ContentView.swift:25 |
| Suspension boundary | await suspension point |
The source declares or crosses an asynchronous boundary; it does not by itself establish background execution. | GaussianSplatsOnVisionOS/ContentView.swift:25 |
| Detached task | Task.detached |
The source creates a detached task; no specific operating-system thread is established. | GaussianSplatsOnVisionOS/PLYLoader.swift:29 |
| Transfer contract | Sendable or @Sendable |
The source declares a sendability boundary; this alone does not synchronize mutable state. | GaussianSplatsOnVisionOS/SplatEntityBuilder.swift:21 |
@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
GaussianSplatsOnVisionOS/AppModel.swift:11 — representative execution boundary
@MainActor
@Observable
class AppModel {
// ...
case closed
// ...
}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 | @Observable |
Observation macro publishes source-visible changes. | GaussianSplatsOnVisionOS/AppModel.swift:12 |
| State propagation | SwiftUI state property wrapper |
A SwiftUI property wrapper supplies or observes UI state. | GaussianSplatsOnVisionOS/ContentView.swift:11 |
| Source import | RealityKit |
The cited file imports this module; runtime use and architectural role are not inferred. | GaussianSplatsOnVisionOS/PLYLoader.swift:10 |
| Source import | Foundation |
The cited file imports this module; runtime use and architectural role are not inferred. | GaussianSplatsOnVisionOS/PLYLoader.swift:9 |
| Source import | SwiftUI |
The cited file imports this module; runtime use and architectural role are not inferred. | GaussianSplatsOnVisionOS/AppModel.swift:9 |
| Source import | ARKit |
The cited file imports this module; runtime use and architectural role are not inferred. | GaussianSplatsOnVisionOS/SceneReconstructionManager.swift:10 |
| Source import | os |
The cited file imports this module; runtime use and architectural role are not inferred. | GaussianSplatsOnVisionOS/SceneReconstructionManager.swift:11 |
| Source import | Metal |
The cited file imports this module; runtime use and architectural role are not inferred. | GaussianSplatsOnVisionOS/SplatEntityBuilder.swift:51 |
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
GaussianSplatsOnVisionOS/GaussianSplatsOnVisionOSApp.swift:11 — representative type boundary
@main
struct GaussianSplatsOnVisionOSApp: App {
@State private var appModel = AppModel()
// ...
}| Type | Responsibility | Depends on or conforms to |
|---|---|---|
GaussianSplatsOnVisionOSApp |
Application entry and top-level composition | App |
AppModel |
Feature data or observable state | Concrete collaborators/imported frameworks |
SplatViewCoordinator |
Cross-object flow or session coordination | Concrete collaborators/imported frameworks |
SplatView |
User-interface presentation and input forwarding | View |
ContentView |
User-interface presentation and input forwarding | View |
SceneReconstructionManager |
Long-lived feature or framework coordination | Concrete collaborators/imported frameworks |
ImmersiveSpaceState |
Represents mutable feature state | Concrete collaborators/imported frameworks |
LoadedAsset |
Defines a closed set of feature states or choices | Concrete collaborators/imported frameworks |
SnapOffset |
Represents a feature value or composable behavior | Concrete collaborators/imported frameworks |
GaussianSplatBuffers |
Represents a feature value or composable behavior | @unchecked Sendable |
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 |
|---|---|---|---|
appModel (GaussianSplatsOnVisionOS/ContentView.swift:11) |
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. |
openImmersiveSpace (GaussianSplatsOnVisionOS/ContentView.swift:12) |
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. |
dismissImmersiveSpace (GaussianSplatsOnVisionOS/ContentView.swift:13) |
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. |
load (GaussianSplatsOnVisionOS/ContentView.swift:37) |
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
GaussianSplatsOnVisionOS/ContentView.swift:11 — representative boundary
struct ContentView: View {
@Environment(AppModel.self) private var appModel
// ...
}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 | GaussianSplatsOnVisionOSApp |
The source’s App suffix makes this role explicit. |
| Cross-object flow or session coordination | SplatViewCoordinator |
The source’s Coordinator suffix makes this role explicit. |
| Long-lived feature or framework coordination | SceneReconstructionManager |
The source’s Manager suffix makes this role explicit. |
| Feature data or observable state | AppModel |
The source’s Model suffix makes this role explicit. |
| User-interface presentation and input forwarding | ContentView, SplatView |
The source’s View suffix makes this role explicit. |
Design patterns
| Pattern | Source evidence | Purpose or tradeoff |
|---|---|---|
| Coordinator | GaussianSplatsOnVisionOS/SplatView.swift:34 |
A role-named coordinator centralizes cross-object flow. |
Main application flow
sequenceDiagram
participant SceneReconstructionManager
participant session
participant provider
SceneReconstructionManager->>session: requestAuthorization()
SceneReconstructionManager->>session: run()
provider-->>SceneReconstructionManager: update() stream
SceneReconstructionManager->>SceneReconstructionManager: applyAnchor()
Reference code
GaussianSplatsOnVisionOS/SceneReconstructionManager.swift:54 — run()
func run() async {
guard SceneReconstructionProvider.isSupported else {
logger.notice("This device does not support scene reconstruction. Splats won't snap to surfaces.")
return
}
let auth = await session.requestAuthorization(for: [.worldSensing])
guard auth[.worldSensing] == .allowed else {
logger.notice("The user did not grant world-sensing authorization. Splats won't snap to surfaces.")
return
}
do {
try await session.run([provider])
} catch {
logger.error("ARKitSession.run failed: \(error, privacy: .public)")
return
}
for await update in provider.anchorUpdates {
switch update.event {
case .added, .updated:
await applyAnchor(update.anchor)
case .removed:
meshEntities.removeValue(forKey: update.anchor.id)?.removeFromParent()
}
}
}Naming conventions
- Types: App: GaussianSplatsOnVisionOSApp; Coordinator: SplatViewCoordinator; Manager: SceneReconstructionManager; Model: AppModel; View: ContentView, SplatView.
- Protocols: no local protocol declaration in the scanned source.
- Methods:
configureSpotLight,syncSplat,loadAsset,configureManipulableObject,snapToNearestSurface,makeSplatEntity,makeDescriptor,makeSHDescriptor. - Files:
GaussianSplatsOnVisionOS/GaussianSplatsOnVisionOSApp.swift,GaussianSplatsOnVisionOS/AppModel.swift,GaussianSplatsOnVisionOS/SplatView.swift,GaussianSplatsOnVisionOS/ContentView.swift,GaussianSplatsOnVisionOS/SceneReconstructionManager.swift.
Architecture takeaways
GaussianSplatsOnVisionOSAppis the main source-visible entry or composition anchor for this sample.- Framework work reaches RealityKit, SwiftUI, ARKit, Metal 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 |
|---|---|
GaussianSplatsOnVisionOS/GaussianSplatsOnVisionOSApp.swift |
Cited implementation, GaussianSplatsOnVisionOSApp |
GaussianSplatsOnVisionOS/ContentView.swift |
Cited implementation, Task, await suspension point, SwiftUI state property wrapper, ContentView |
GaussianSplatsOnVisionOS/SplatView.swift |
SplatViewCoordinator, SplatView, SnapOffset |
GaussianSplatsOnVisionOS/AppModel.swift |
@MainActor, @Observable, SwiftUI, AppModel, ImmersiveSpaceState, LoadedAsset |
GaussianSplatsOnVisionOS/PLYLoader.swift |
Task.detached, RealityKit, Foundation, Feature implementation |
GaussianSplatsOnVisionOS/SplatEntityBuilder.swift |
Sendable or @Sendable, Metal, GaussianSplatBuffers, GaussianSplatError |
GaussianSplatsOnVisionOS/SceneReconstructionManager.swift |
ARKit, os, SceneReconstructionManager |
GaussianSplatsOnVisionOS/PLYParser.swift |
PLYProperty, GaussianSplatData, PLYHeader, ElementInfo |
GaussianSplatsOnVisionOS/USDLoader.swift |
SplatAttributes |