ARKit 4について – WWDC2020

// 可用性の確認
// Check device support for geo-tracking
guard ARGeoTrackingConfiguration.isSupported else {
    // Geo-tracking not supported on this device
    return
}

// Check current location is supported for geo-tracking
ARGeoTrackingConfiguration.checkAvailability { (available, error) in
    guard available else {
        // Geo-tracking not supported at current location
        return
    }
    // Run ARSession
    let arView = ARView()
    // ワールドロケーションを使用するため、セッション実行時にジオトラッキングコンフィギュレーションを設定する
    arView.session.run(ARGeoTrackingConfiguration())
}

// Create coordinates
// マップデータを使用して標高を決定するので、高度を指定する必要はない 
let coordinate = CLLocationCoordinate2D(latitude: 37.795313, longitude: -122.393792)

// Create Location Anchor
let geoAnchor = ARGeoAnchor(name: "Ferry Building", coordinate: coordinate)

// Add Location Anchor to session
arView.session.add(anchor: geoAnchor)

// Create a RealityKit anchor entity 
let geoAnchorEntity = AnchorEntity(anchor: geoAnchor)

// Anchor content under the RealityKit anchor
geoAnchorEntity.addChild(generateSignEntity())

// Add the RealityKit anchor to the scene
arView.scene.addAnchor(geoAnchorEntity)

// オブジェクトの回転と高さ調整
// Create a new entity for our virtual content
let signEntity = generateSignEntity();

// Add the virtual content entity to the Geo Anchor entity
geoAnchorEntity.addChild(signEntity)

// Rotate text to face the city
let orientation = simd_quatf.init(angle: -Float.pi / 3.5, axis: SIMD3<Float>(0, 1, 0))
signEntity.setOrientation(orientation, relativeTo: geoAnchorEntity)

// Elevate text to 35 meters above ground level
let position = SIMD3<Float>(0, 35, 0)
signEntity.setPosition(position, relativeTo: geoAnchorEntity)

// Enabling the depth API

let session = ARSession()
let configuration = ARWorldTrackingConfiguration()

// Check if configuration and device supports .sceneDepth
// .sceneDepthという新しいframeSemanticを用いてDepth APIをオンにする
// そのため、利用可能かチェックする
if type(of: configuration).supportsFrameSemantics(.sceneDepth) {
    // Activate sceneDepth
    configuration.frameSemantics = .sceneDepth
}
session.run(configuration)

...

// Accessing depth data
func session(_ session: ARSession, didUpdate frame: ARFrame) {
    guard let depthData = frame.sceneDepth else { return }
    // Use depth data
}

// Using the depth API alongside person occlusion

let session = ARSession()
let configuration = ARWorldTrackingConfiguration()

// Set required frame semantics
// ピープルオクルージョン機能は.personSegmentationWithDepthを設定する
// アプリへの電力負荷を増やさずsceneDepthframeSemanticをサポートするデバイスに自動でsceneDepthを得られます
let semantics: ARConfiguration.FrameSemantics = .personSegmentationWithDepth
        
// Check if configuration and device supports the required semantics
if type(of: configuration).supportsFrameSemantics(semantics) {
    // Activate .personSegmentationWithDepth
    configuration.frameSemantics = semantics
}
session.run(configuration)

let session = ARSession()
hitTest(point, types: [.existingPlaneUsingGeometry,
                       .estimatedVerticalPlane,
                       .estimatedHorizontalPlane])

let query = arView.makeRaycastQuery(from: point,
                                    allowing: .estimatedPlane,
                                    alignment: .any)

let raycast = session.trackedRaycast(query) { results in
   // result updates
}