探索 visionOS 对象追踪的增强功能

3:50 - Enable high frame rate tracking

// Enable high frame rate tracking

// Create reference object configuration
var configuration = ReferenceObject.Configuration()
configuration.highFrameRateTrackingEnabled = true

// Load the reference object with ARKit API
let refObjURL = Bundle.main.url(forResource: "flashlight", withExtension: ".referenceobject")
let refObject = try? await ReferenceObject(from: refObjURL!, configuration: configuration)

4:50 - Extended training mode via command-line

// Extended training mode on Mac using command-line interface

% xrun createml objecttracker --source flashlight.usdz --output flashlight.referenceobject --training-mode extended --all-angles

5:25 - Object pose coordinate spaces

// Different object pose spaces

// Obtain anchor transform with display corrections

let renderingPose = myObjectAnchor.coordinateSpace(correction: .rendered)

// Obtain anchor transform in metric space

let metricPose = myObjectAnchor.coordinateSpace(correction: .none)

6:22 - Implement object tracking in iOS

// Implement object tracking in iOS

import ARKit
import RealityKit

class ObjectTrackingARSessionDelegate: NSObject, ARSessionDelegate {
        let arView = ARView(frame: .zero)
        var entities: [UUID: AnchorEntity] = [:]

        func start() throws {
                let stationaryObject = try ARReferenceObject(archiveURL:
                        Bundle.main.url(forResource: "stationary", withExtension: "referenceobject")!)
                let movingObject = try ARReferenceObject(archiveURL:
                        Bundle.main.url(forResource: "moving", withExtension: "referenceobject")!)

                let configuration = ARWorldTrackingConfiguration()
                configuration.detectionObjects = [stationaryObject]   // Low frame rate
                configuration.trackingObjects = [movingObject]        // High frame rate

                arView.session.delegate = self
                arView.session.run(configuration)
        }

				func session(_ session: ARSession, didAdd anchors: [ARAnchor]) {
                for case let anchor as ARObjectAnchor in anchors {
                        let entity = AnchorEntity(anchor: anchor)
                        entities[anchor.identifier] = entity
                        arView.scene.addAnchor(entity)
                }
        }

        func session(_ session: ARSession, didUpdate anchors: [ARAnchor]) {
                for case let anchor as ARObjectAnchor in anchors {
                        entities[anchor.identifier]?.isEnabled = anchor.isTracked
                }
        }

        func session(_ session: ARSession, didRemove anchors: [ARAnchor]) {
                for case let anchor as ARObjectAnchor in anchors {
                        if let entity = entities.removeValue(forKey: anchor.identifier) {
                                arView.scene.removeAnchor(entity)
                        }
                }
        }
}

12:26 - Discover and connect a spatial accessory

import ARKit
import GameController

// Generic accessory discovery

if let device = GCSpatialAccessory.spatialAccessories.first {

        // Resolves the .referenceaccessory bundle automatically
        
        let accessory = try await Accessory(device: device)
        let provider = AccessoryTrackingProvider(accessories: [accessory])
        try await arkitSession.run([provider])
}

// Update tracked accessories without restarting the session                             

try await provider.updateAccessories([newAccessory])