问如何为单个图像有多个选择选项？

EN

import UIKit
import SceneKit

class ViewController: UIViewController {

    @IBOutlet var scenekitView: SCNView!

    override func viewDidLoad() {
        super.viewDidLoad()

        let scene = SCNScene()

        let boxNode = SCNNode(geometry: SCNBox(width: 1, height: 1, length: 1, chamferRadius: 0))
        boxNode.name = "box"
        scene.rootNode.addChildNode(boxNode)

        let sphereNode = SCNNode(geometry: SCNSphere(radius: 1))
        sphereNode.name = "sphere"
        sphereNode.position = SCNVector3Make(2, 0, 0)
        boxNode.addChildNode(sphereNode)

        let torusNode = SCNNode(geometry: SCNTorus(ringRadius: 1, pipeRadius: 0.3))
        torusNode.name = "torus"
        torusNode.position = SCNVector3Make(2, 0, 0)
        sphereNode.addChildNode(torusNode)

        scenekitView.scene = scene
        scenekitView.autoenablesDefaultLighting = true
        scenekitView.allowsCameraControl = true
    }

    override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {

        //get the first touch location in screen coordinates
        guard let touch = touches.first else {
            return
        }

        //convert the screen coordinates to view coordinates as the SCNView make not take
        //up the entire screen.
        let pt = touch.locationInView(self.scenekitView)

        //pass a ray from the points 2d coordinates into the scene, returning a list
        //of objects it hits
        let hits = self.scenekitView.hitTest(pt, options: nil)

        for hit in hits {
            //do something with each hit
            print("touched ", hit.node.name!)
        }
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }
}