问RealityKit:未能从USDZ文件加载实体

EN

import UIKit
import ARKit
import RealityKit

class ViewController: UIViewController {
    @IBOutlet var arView: ARView!
    
    // this one does not show
    var glassesEntity: Entity {
        guard let fileUrl = Bundle.main.url(forResource: "glasses", withExtension: "usdz"), 
              let entity = try? Entity.loadModel(contentsOf: fileUrl) else {
            fatalError("could not load entity")
        }
        
        entity.name = "glasses"
        print(entity)
        return entity
    }
    
    // this one works perfectly fine
    var boxEntity: Entity {
        let box = MeshResource.generateBox(size: 0.3)
        return ModelEntity(mesh: box)
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let arConfiguration = ARFaceTrackingConfiguration()
        
        arView.session.run(arConfiguration, options: [])
        
        let faceAnchor = AnchorEntity(AnchoringComponent.Target.face)
        arView.scene.addAnchor(faceAnchor)
        
        faceAnchor.addChild(glassesEntity)
        // If I uncomments this line, I see the box on my face 
        // faceAnchor.addChild(boxEntity)
    }
}

2021-04-05 10:52:39.589170+0300 FaceTracking[27470:2201299] Metal GPU Frame Capture Enabled
2021-04-05 10:52:39.589627+0300 FaceTracking[27470:2201299] Metal API Validation Enabled
Json Parse Error line 22: Json Deserialization; unknown member 'EnableGuidedFilterOcclusion' - skipping.
Warning: in AppendProperty at line 859 of sdf/path.cpp -- Can only append a property 'preliminary:anchoring:type' to a prim path (/)
Warning: in AppendProperty at line 859 of sdf/path.cpp -- Can only append a property 'triggers' to a prim path (/)
▿ 'glasses' : ModelEntity
  ⟐ ModelComponent
  ⟐ SynchronizationComponent
  ⟐ Transform

2021-04-05 10:52:40.549771+0300 FaceTracking[27470:2201340] [Graphics] Failed to find reflection for buffer clusterIndexTable