问Swift / ARKit:将对象节点放置在检测到的表面而不接触屏幕

EN

var surfaceDetected = false

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    sceneView.delegate = self
    let configuration = ARWorldTrackingConfiguration()
    configuration.planeDetection = .horizontal
    sceneView.session.run(configuration)
}

func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) {

    guard !surfaceDetected else { return }
    surfaceDetected = true

    guard let planeAnchor = anchor as? ARPlaneAnchor else { return }

    let x = CGFloat(planeAnchor.transform.columns.3.x)
    let y = CGFloat(planeAnchor.transform.columns.3.y)
    let z = CGFloat(planeAnchor.transform.columns.3.z)
    let position = SCNVector3(x,y,z)

    sceneView.scene.rootNode.addChildNode(yourNode)
    yourNode.position = position 

}