https://x.com/banjun/status/1871886052069404768

KibouApp.swift

import SwiftUI
import RealityKit

@main
struct KibouApp: App {
    @Environment(\.scenePhase) private var scenePhase
    @State private var transform: Transform = .identity
    @GestureState private var dragState: SIMD3<Float>?

    var body: some SwiftUI.Scene {
        ImmersiveSpace(id: "i") {
            RealityView { content in
                let kibou = try! await Entity(named: "Assets_KIBOU_gltf")
                content.add(kibou)

                let sphere = ModelEntity(mesh: .generateSphere(radius: 10))
                sphere.components.set(InputTargetComponent(allowedInputTypes: .indirect))
                sphere.components.set(CollisionComponent(shapes: [.generateSphere(radius: 10)]))
                content.add(sphere)

                let light = PointLight()
                light.position.y = 1.5
                content.add(light)
            } update: { content in
                let root = content.entities.first!
                root.transform = transform //.init(matrix: transform.matrix.inverse)
            }
            .gesture(DragGesture(coordinateSpace: .immersiveSpace).targetedToAnyEntity().updating($dragState) { value, state, transaction in
                state = state ?? transform.translation
                var translation = value.translation3D / 1000
                translation.y = 0
                transform = .init(translation: state! + .init(translation))
            })
        }
        .immersionStyle(selection: .constant(.progressive(0.3..., initialAmount: 1)), in: .progressive)
        .onChange(of: scenePhase) { _, new in
            if new == .background { exit(0) }
        }
    }
}