visionOS 27 RealityKit Gaussian Splatting

import SwiftUI
import RealityKit

@main
struct GaussianSplatDemoApp: App {
    var body: some Scene {
        WindowGroup {
            ContentView()
        }

        ImmersiveSpace(id: "SplatSpace") {
            SplatImmersiveView()
        }
    }
}

struct ContentView: View {
    @Environment(\.openImmersiveSpace) private var openImmersiveSpace
    @Environment(\.dismissImmersiveSpace) private var dismissImmersiveSpace
    @State private var isImmersive = false

    var body: some View {
        VStack(spacing: 20) {
            Text("Gaussian Splat Viewer")
                .font(.title)
            Button(isImmersive ? "Exit Immersive Space" : "View Scanned Plant") {
                Task {
                    if isImmersive {
                        await dismissImmersiveSpace()
                    } else {
                        await openImmersiveSpace(id: "SplatSpace")
                    }
                    isImmersive.toggle()
                }
            }
        }
        .padding()
    }
}

struct SplatImmersiveView: View {
    var body: some View {
        RealityView { content in
            // Load a Gaussian splat entity from a .splat asset in the app bundle
            if let splatEntity = try? await GaussianSplatEntity(
                contentsOf: Bundle.main.url(forResource: "potted_plant", withExtension: "splat")!
            ) {
                // Position the scanned plant roughly on a surface in front of the user
                splatEntity.position = SIMD3<Float>(0, -0.5, -1.2)
                splatEntity.scale = SIMD3<Float>(repeating: 0.8)
                content.add(splatEntity)
            }
        }
    }
}