Sample CodevisionOSReviewed 2026-07-21View on Apple Developer

Gaussian splats on visionOS

At a glance

Item Summary
Purpose Use the new Gaussian splat APIs available in RealityKit in visionOS 27.
App architecture GaussianSplatsOnVisionOSApp composes WindowGroup + ImmersiveSpace around ContentView; AppModel coordinates scene-reconstruction updates while a dedicated coordinator/renderer owns Gaussian-splat resources.
Main patterns SwiftUI scene composition, SwiftUI–RealityKit bridge, Explicit immersive-space lifecycle, Observable state owner, Provider session boundary, Low-level render-buffer builder
Project style Code-rich sample with 9 scanned Swift file(s) and 1151 Swift line(s); resources and generated assets are excluded from those counts.

Project structure

Source bundle/
└── GaussianSplatsOnVisionOS/
    ├── GaussianSplatsOnVisionOSApp.swift  # GaussianSplatsOnVisionOSApp
    ├── AppModel.swift  # AppModel, ImmersiveSpaceState, LoadedAsset
    ├── SplatView.swift  # SplatViewCoordinator, SplatView, SnapOffset
    ├── SplatEntityBuilder.swift  # GaussianSplatBuffers, GaussianSplatError
    ├── ContentView.swift  # ContentView
    ├── SceneReconstructionManager.swift  # SceneReconstructionManager
    ├── PLYParser.swift  # PLYProperty, GaussianSplatData, PLYHeader
    └── USDLoader.swift  # SplatAttributes

Structure observations

  • The runtime boundary is WindowGroup + ImmersiveSpace; the pruned tree lists only files that explain lifecycle, state, or framework integration.
  • App code is split into role-named views, models, managers, providers, components, or systems.

Overall architecture

Reference code

GaussianSplatsOnVisionOS/GaussianSplatsOnVisionOSApp.swift:11 — the app or executable entry declares the outer scene lifecycle.

struct GaussianSplatsOnVisionOSApp: App {
    // ...
}

The diagram is a responsibility flow, not a claim that every adjacent node directly calls the next. It keeps scene ownership, shared state, RealityKit content, and framework-provider work at separate levels.

Ownership and state

Ownership evidence

GaussianSplatsOnVisionOS/GaussianSplatsOnVisionOSApp.swift:12 — representative stored state or the nearest verified lifecycle anchor.

    @State private var appModel = AppModel()
Owner Object or state Relationship Mutation authority
GaussianSplatsOnVisionOSApp AppModel as appModel creates and retains Only the declaring scope writes
ContentView AppModel as appModel receives a shared/non-owning reference The upstream owner controls lifetime; this scope may invoke its mutable API
SceneReconstructionManager ARKitSession as session creates and retains Only the declaring scope writes
SplatView SplatViewCoordinator as coordinator creates and retains Only the declaring scope writes

Ownership here is deliberately narrow: @Environment and weak references are shared links, initialized @State or stored services are lifecycle ownership, and a RealityView content closure owns additions to its entity graph without making the SwiftUI view a reference-type owner.

Class and protocol design

Type Responsibility Depends on or conforms to
GaussianSplatsOnVisionOSApp (GaussianSplatsOnVisionOS/GaussianSplatsOnVisionOSApp.swift:11) Declares app scenes and top-level dependency lifetime. App
ContentView (GaussianSplatsOnVisionOS/ContentView.swift:10) Presents UI and forwards gestures or lifecycle events. View
AppModel (GaussianSplatsOnVisionOS/AppModel.swift:13) Owns observable feature state and domain transitions. Concrete framework collaborators
SplatViewCoordinator (GaussianSplatsOnVisionOS/SplatView.swift:34) Coordinates long-lived framework or cross-view work. Concrete framework collaborators
SceneReconstructionManager (GaussianSplatsOnVisionOS/SceneReconstructionManager.swift:24) Coordinates long-lived framework or cross-view work. Concrete framework collaborators
SplatView (GaussianSplatsOnVisionOS/SplatView.swift:75) Presents UI and forwards gestures or lifecycle events. View

The source defines no local substitution protocol in the reviewed boundary. Its protocol use is framework-facing (App, View, RealityKit/ARKit protocols, or platform adapters), so this document does not label the whole app protocol-oriented.

Access control

Symbol Access Verified effect Likely rationale
@Environment(AppModel.self) private var appModel (GaussianSplatsOnVisionOS/ContentView.swift:11) private Use is restricted to the declaration and same-file extensions permitted by Swift. Inference: Hide implementation details and lifecycle-sensitive state.

No reviewed declaration uses fileprivate, private(set), public, open; unmodified Swift declarations are internal.

Reference code

GaussianSplatsOnVisionOS/ContentView.swift:11 — representative visibility boundary.

    @Environment(AppModel.self) private var appModel

Logic ownership and placement

Logic Owning type or file Placement rationale
Scene declaration and dependency lifetime GaussianSplatsOnVisionOSApp The App/entry boundary determines window, volume, and immersive-space lifetime.
Presentation, attachments, and gestures ContentView SwiftUI view code forwards user intent and RealityView lifecycle events.
Shared feature state and commands AppModel A role-named owner prevents sibling views from duplicating transitions.
Tracking authorization and update streams GaussianSplatsOnVisionOS/SceneReconstructionManager.swift:32 Provider lifetime and async updates remain outside render-only view code.

Design patterns

Pattern Source evidence Purpose or tradeoff
SwiftUI scene composition GaussianSplatsOnVisionOS/GaussianSplatsOnVisionOSApp.swift:11 Keeps windows, volumes, and immersive-space lifecycle visible at the app boundary.
SwiftUI–RealityKit bridge GaussianSplatsOnVisionOS/SplatView.swift:88 Builds and updates a RealityKit entity graph from SwiftUI lifecycle closures.
Explicit immersive-space lifecycle GaussianSplatsOnVisionOS/GaussianSplatsOnVisionOSApp.swift:21 Makes immersive presentation a scene transition rather than hidden global state.
Observable state owner GaussianSplatsOnVisionOS/AppModel.swift:13 Shares feature state across multiple views without moving framework resources into view values.
Provider session boundary GaussianSplatsOnVisionOS/SceneReconstructionManager.swift:32 Owns provider lifetime separately from the SwiftUI view tree.
Low-level render-buffer builder GaussianSplatsOnVisionOS/SplatEntityBuilder.swift:17 Parses asset fields into GPU-oriented buffers before the coordinator installs the splat entity.

Naming conventions

  • Role suffixes are evidence, not decoration: App: GaussianSplatsOnVisionOSApp; Model: AppModel; Coordinator: SplatViewCoordinator; Manager: SceneReconstructionManager.
  • Protocols: no app-defined protocol in the reviewed source.
  • Commands use verb-led methods: configureSpotLight, syncSplat, loadAsset, configureManipulableObject, snapToNearestSurface, makeSplatEntity, makeDescriptor, makeSHDescriptor.
  • Files generally match their primary type; Views, Models, Managers, Providers, Components, Systems, and Packages folders describe architectural roles where present.

Architecture takeaways

  • Treat GaussianSplatsOnVisionOSApp as the owner of scene declarations, not as the owner of every RealityKit entity created later.
  • Keep view-local interaction in SwiftUI, but move provider sessions, playback resources, shared game state, or transport state into a stable owner when their lifetime exceeds one render pass.
  • Run ARKit providers for the scene lifetime and consume their asynchronous updates in cancellable tasks; map anchors to entities at the boundary.
  • Model immersive-space open, transition, and close states explicitly so windows and immersive content cannot drift apart.

Source map

Source file Relevant symbols
GaussianSplatsOnVisionOS/GaussianSplatsOnVisionOSApp.swift:11 GaussianSplatsOnVisionOSApp
GaussianSplatsOnVisionOS/AppModel.swift:13 AppModel, ImmersiveSpaceState, LoadedAsset
GaussianSplatsOnVisionOS/SplatView.swift:34 SplatViewCoordinator, SplatView, SnapOffset
GaussianSplatsOnVisionOS/SplatEntityBuilder.swift:21 GaussianSplatBuffers, GaussianSplatError
GaussianSplatsOnVisionOS/ContentView.swift:10 ContentView
GaussianSplatsOnVisionOS/SceneReconstructionManager.swift:24 SceneReconstructionManager
GaussianSplatsOnVisionOS/PLYParser.swift:34 PLYProperty, GaussianSplatData, PLYHeader, ElementInfo
GaussianSplatsOnVisionOS/USDLoader.swift:58 SplatAttributes