Apple Vision Pro Dev Kit: Building Spatial Computing Apps

The Apple Vision Pro has opened an entirely new dimension for app development. Spatial computing isn't just about putting flat screens in 3D space—it's about reimagining how humans interact with digital content. This comprehensive guide will help you master visionOS development.

Understanding Spatial Computing

Spatial computing represents the convergence of the physical and digital worlds:

Core Concepts

• Spatial awareness: Apps understand and interact with physical space
• Immersive experiences: Content that surrounds and engages users
• Natural interaction: Eye tracking, hand gestures, and voice control
• Shared spaces: Multiple apps coexisting in your environment

Setting Up Your Development Environment

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// Requirements
- macOS 14.0 or later
- Xcode 15.2 or later
- visionOS SDK
- Reality Composer Pro
- At least 16GB RAM (32GB recommended)
- Apple Silicon Mac (M1 or later)

Creating Your First visionOS App

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import SwiftUI
import RealityKit
import RealityKitContent

@main
struct VisionProApp: App {
    var body: some Scene {
        // Window Group for 2D content
        WindowGroup {
            ContentView()
        }
        .windowStyle(.plain)
        .windowResizability(.contentSize)

        // Immersive Space for 3D content
        ImmersiveSpace(id: "ImmersiveSpace") {
            ImmersiveView()
        }
        .immersionStyle(selection: .constant(.mixed), in: .mixed)
    }
}

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

    var body: some View {
        VStack(spacing: 30) {
            Text("Welcome to Spatial Computing")
                .font(.extraLargeTitle)

            Toggle("Show Immersive Space", isOn: $showImmersive)
                .toggleStyle(.button)
                .font(.title)
                .onChange(of: showImmersive) { _, newValue in
                    Task {
                        if newValue {
                            await openImmersiveSpace(id: "ImmersiveSpace")
                        } else {
                            await dismissImmersiveSpace()
                        }
                    }
                }
        }
        .padding(50)
        .glassBackgroundEffect()
    }
}

Building Immersive Experiences

3D Content with RealityKit

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struct ImmersiveView: View {
    @State private var entities: [ModelEntity] = []

    var body: some View {
        RealityView { content, attachments in
            // Create a 3D scene
            let model = ModelEntity(
                mesh: .generateSphere(radius: 0.1),
                materials: [SimpleMaterial(color: .purple, isMetallic: true)]
            )

            // Add physics
            model.components.set(PhysicsBodyComponent())
            model.components.set(CollisionComponent(shapes: [.generateSphere(radius: 0.1)]))

            // Position in space
            model.position = SIMD3(x: 0, y: 1.5, z: -1)

            // Add to scene
            content.add(model)

            // Add lighting
            let light = DirectionalLight()
            light.light.intensity = 1000
            light.orientation = simd_quatf(angle: -.pi/4, axis: [1, 0, 0])
            content.add(light)

            // Add attachment
            if let attachment = attachments.entity(for: "info") {
                attachment.position = SIMD3(x: 0.2, y: 0, z: 0)
                model.addChild(attachment)
            }
        } attachments: {
            Attachment(id: "info") {
                VStack {
                    Text("Interactive Object")
                        .font(.headline)
                    Text("Tap to interact")
                        .font(.caption)
                }
                .padding()
                .glassBackgroundEffect()
            }
        }
    }
}

Eye Tracking and Hand Gestures

Implementing Eye Tracking

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struct EyeTrackingView: View {
    @State private var lookAtPoint: CGPoint = .zero
    @State private var highlightedItem: String?

    var body: some View {
        GeometryReader { geometry in
            ForEach(items) { item in
                ItemView(item: item)
                    .hoverEffect()
                    .onLookAtChanged { isLooking in
                        highlightedItem = isLooking ? item.id : nil
                    }
                    .scaleEffect(highlightedItem == item.id ? 1.1 : 1.0)
                    .animation(.spring(), value: highlightedItem)
            }
        }
    }
}

// Custom view modifier for eye tracking
extension View {
    func onLookAtChanged(perform action: @escaping (Bool) -> Void) -> some View {
        self.modifier(LookAtModifier(action: action))
    }
}

struct LookAtModifier: ViewModifier {
    let action: (Bool) -> Void
    @State private var isBeingLookedAt = false

    func body(content: Content) -> some View {
        content
            .accessibilityHidden(false)
            .onReceive(NotificationCenter.default.publisher(
                for: .ARKitSession.lookAtStateChanged
            )) { notification in
                if let userInfo = notification.userInfo,
                   let isLooking = userInfo["isLooking"] as? Bool {
                    isBeingLookedAt = isLooking
                    action(isLooking)
                }
            }
    }
}

Hand Gesture Recognition

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import ARKit

struct HandGestureView: View {
    @StateObject private var handTracker = HandTracker()

    var body: some View {
        RealityView { content in
            // Setup hand tracking
            let session = ARKitSession()
            let handTracking = HandTrackingProvider()

            do {
                try await session.run([handTracking])

                for await update in handTracking.anchorUpdates {
                    switch update.event {
                    case .added, .updated:
                        if let handAnchor = update.anchor as? HandAnchor {
                            processHandGesture(handAnchor)
                        }
                    case .removed:
                        break
                    }
                }
            } catch {
                print("Hand tracking failed: \(error)")
            }
        }
    }

    func processHandGesture(_ hand: HandAnchor) {
        // Detect pinch gesture
        let thumb = hand.jointPositions[.thumbTip]
        let index = hand.jointPositions[.indexFingerTip]

        if let thumbPos = thumb, let indexPos = index {
            let distance = simd_distance(thumbPos, indexPos)
            if distance < 0.02 { // Pinch detected
                handlePinchGesture()
            }
        }

        // Detect open palm
        if isOpenPalm(hand) {
            handleOpenPalmGesture()
        }
    }
}

Spatial Audio

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import AVFoundation
import RealityKit

class SpatialAudioManager {
    private var audioEngine = AVAudioEngine()
    private var environment = AVAudioEnvironmentNode()

    init() {
        setupAudioEngine()
    }

    func setupAudioEngine() {
        audioEngine.attach(environment)
        audioEngine.connect(
            environment,
            to: audioEngine.mainMixerNode,
            format: nil
        )

        // Configure spatial rendering
        environment.renderingAlgorithm = .HRTFHQ
        environment.reverbBlend = 0.3
        environment.distanceAttenuationParameters.maximumDistance = 10
    }

    func playSound(at position: SIMD3<Float>) {
        let player = AVAudioPlayerNode()
        audioEngine.attach(player)

        // Position the sound in 3D space
        let x = position.x
        let y = position.y
        let z = -position.z // Convert to AVAudio3D coordinate system

        player.position = AVAudio3DPoint(x: x, y: y, z: z)
        player.renderingAlgorithm = .HRTFHQ

        // Load and play audio
        if let file = loadAudioFile("sound.mp3") {
            player.scheduleFile(file, at: nil)
            player.play()
        }
    }
}

SharePlay and Collaboration

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import GroupActivities

struct SharedSpatialExperience: GroupActivity {
    static let activityIdentifier = "com.app.shared.spatial"

    var metadata: GroupActivityMetadata {
        var metadata = GroupActivityMetadata()
        metadata.title = "Shared Spatial Experience"
        metadata.type = .generic
        return metadata
    }
}

class CollaborationManager: ObservableObject {
    @Published var session: GroupSession<SharedSpatialExperience>?
    @Published var sharedObjects: [SharedObject] = []

    func startSharing() async {
        let activity = SharedSpatialExperience()

        switch await activity.prepareForActivation() {
        case .activationPreferred:
            _ = try? await activity.activate()
        case .activationDisabled:
            print("SharePlay is disabled")
        default:
            break
        }
    }

    func configureGroupSession(_ session: GroupSession<SharedSpatialExperience>) {
        self.session = session

        session.$activeParticipants.sink { participants in
            // Update UI based on participants
            self.updateParticipantAvatars(participants)
        }

        session.messenger.messages(of: SharedObjectUpdate.self)
            .sink { message in
                // Sync object positions across devices
                self.updateSharedObject(message)
            }

        session.join()
    }
}

Performance Optimization

Rendering Optimization

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struct OptimizedRealityView: View {
    @State private var renderOptions = RenderOptions()

    var body: some View {
        RealityView { content in
            // Use instancing for repeated objects
            let mesh = MeshResource.generateBox(size: 0.1)
            let material = SimpleMaterial(color: .blue, isMetallic: false)

            // Create instance group
            var instances: [Transform] = []
            for i in 0..<100 {
                var transform = Transform()
                transform.translation = SIMD3(
                    x: Float.random(in: -2...2),
                    y: Float.random(in: 0...3),
                    z: Float.random(in: -2...2)
                )
                instances.append(transform)
            }

            let instancedEntity = ModelEntity(
                mesh: mesh,
                materials: [material]
            )
            instancedEntity.components.set(
                InstanceComponent(transforms: instances)
            )

            content.add(instancedEntity)
        }
        .realityViewRenderOptions(renderOptions)
    }
}

struct RenderOptions: RealityViewRenderOptionsProtocol {
    let maximumFrameRate: Int = 90
    let colorFormat: MTLPixelFormat = .bgra8Unorm_srgb
    let depthFormat: MTLPixelFormat = .depth32Float
    let usesLowLatencyRendering: Bool = true
}

Testing and Debugging

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import XCTest
import RealityKit

class VisionProTests: XCTestCase {
    func testSpatialInteraction() async throws {
        let view = ImmersiveView()
        let controller = UIHostingController(rootView: view)

        // Simulate eye tracking
        let eyeTrackingSimulator = EyeTrackingSimulator()
        eyeTrackingSimulator.lookAt(point: CGPoint(x: 100, y: 100))

        // Simulate hand gesture
        let handSimulator = HandGestureSimulator()
        handSimulator.performPinch(at: SIMD3(x: 0, y: 1, z: -1))

        // Verify interaction
        XCTAssertNotNil(controller.selectedObject)
    }

    func testPerformance() {
        measure {
            // Test rendering performance
            let entities = (0..<1000).map { _ in
                ModelEntity(mesh: .generateSphere(radius: 0.05))
            }

            // Measure time to update all entities
            entities.forEach { entity in
                entity.transform.translation.x += 0.1
            }
        }
    }
}

App Store Guidelines

Design Principles

• Comfort: Avoid sudden movements and maintain user comfort
• Accessibility: Support all input methods (eyes, hands, voice)
• Privacy: Clearly communicate data usage, especially for eye tracking
• Performance: Maintain 90 FPS for optimal experience

Submission Checklist

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- [ ] Test on actual Vision Pro hardware
- [ ] Optimize for battery life
- [ ] Implement proper privacy descriptions
- [ ] Support dynamic type and accessibility
- [ ] Handle space transitions gracefully
- [ ] Provide 3D app icon
- [ ] Include spatial screenshots

Real-World Use Cases

Medical Visualization

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struct MedicalVisualization: View {
    @State private var organModel: ModelEntity?

    var body: some View {
        RealityView { content in
            // Load medical model
            if let model = try? await ModelEntity.load(named: "heart") {
                // Add interactive annotations
                let annotation = createAnnotation(
                    text: "Left Ventricle",
                    position: SIMD3(x: 0.1, y: 0, z: 0)
                )
                model.addChild(annotation)

                content.add(model)
            }
        }
    }
}

Architecture and Design

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struct ArchitecturalViewer: View {
    var body: some View {
        RealityView { content in
            // Load building model at real-world scale
            let building = try? await Entity.load(named: "building")
            building?.scale = SIMD3(repeating: 1.0) // 1:1 scale

            // Allow walking through
            building?.components.set(CollisionComponent(mode: .trigger))

            content.add(building)
        }
    }
}

Future of Spatial Computing

The Vision Pro SDK is just the beginning:

• Neural interfaces: Direct thought control integration
• Haptic feedback: Touch and feel virtual objects
• Persistent AR: Digital objects that stay in place
• Cross-platform spatial: Shared experiences across devices

Conclusion

The Apple Vision Pro isn't just another device—it's a new computing paradigm. As developers, we have the opportunity to define how humanity interacts with technology for the next decade.

Start building today, and be part of the spatial computing revolution!