Swift ARKit 複数のオブジェクトが異なる音声が再生されるようにしたいです。

前提・実現したいこと

Xcode Swift4にてARKitを用い、AR空間にあるオブジェクトをタップすると音が再生されるというアプリを作っています。
最終的には、オブジェクトを複数配置し、それぞれ別の音が鳴るようにしたいと考えています。

例）オブジェクトAは音声1を再生、オブジェクトBは音声2を再生

発生している問題・エラーメッセージ

オブジェクトを2個配置し、同じ音を再生させることは出来たのですが、オブジェクトごとに違う音声を再生させることができません。

該当のソースコード

Swift
1import UIKit
2import SceneKit
3import ARKit
4import AVFoundation
5
6
7class ViewController: UIViewController, ARSCNViewDelegate {
8
9    @IBOutlet var sceneView: ARSCNView!
10    
11    let node1 = SCNNode()
12    let node2 = SCNNode()
13    var audioPlayer1:AVAudioPlayer!
14    var audioPlayer2:AVAudioPlayer!
15    
16    override func viewDidLoad() {
17        super.viewDidLoad()
18        
19        // Set the view's delegate
20        sceneView.delegate = self
21       // sceneView.debugOptions = [.showWorldOrigin, .showFeaturePoints]
22       
23        node1.geometry = SCNSphere(radius: 1)
24        let marerial1 = SCNMaterial()
25        marerial1.diffuse.contents = UIColor(red: 255/255, green: 0/255, blue: 0/255, alpha: 1.0)
26        node1.geometry?.materials = [marerial1]
27        
28        node2.geometry = SCNSphere(radius: 1)
29        let marerial2 = SCNMaterial()
30        marerial2.diffuse.contents = UIColor(red: 0/255, green: 255/255, blue: 0/255, alpha: 1.0)
31        node2.geometry?.materials = [marerial2]
32        
33        
34        let phi1:Double = 252.292
35        let PHI1:Double = phi1 * (.pi/180)
36        let theta1:Double = 69.663
37        let THETA1:Double = theta1 * (.pi/180)
38        
39        let phi2:Double = 246
40        let PHI2:Double = phi2 * (.pi/180)
41        let theta2:Double = 80
42        let THETA2:Double = theta2 * (.pi/180)
43        
44        let r:Double = 100
45        
46        let x1:Double = r * sin(PHI1) * cos(THETA1)
47        let y1:Double = r * sin(THETA1) * sin(PHI1)
48        let z1:Double = r * cos(THETA1)
49        
50        let x2:Double = r * sin(PHI2) * cos(THETA2)
51        let y2:Double = r * sin(THETA2) * sin(PHI2)
52        let z2:Double = r * cos(THETA2)
53        
54        node1.position = SCNVector3(Double(y1), Double(z1), -Double(x1))
55        node2.position = SCNVector3(Double(y2), Double(z2), -Double(x2))
56        
57        sceneView.scene.rootNode.addChildNode(node1)
58        sceneView.scene.rootNode.addChildNode(node2)
59        
60        let audioPath1 = Bundle.main.path(forResource: "sheep-cry1", ofType:"mp3")!
61        let audioPath2 = Bundle.main.path(forResource: "dog1", ofType:"mp3")!
62        
63        let audioUrl1 = URL(fileURLWithPath: audioPath1)
64        let audioUrl2 = URL(fileURLWithPath: audioPath2)
65        
66        var audioError1:NSError?
67        do{
68            audioPlayer1 = try AVAudioPlayer(contentsOf: audioUrl1)
69        } catch let error as NSError {
70            audioError1 = error
71            audioPlayer1 = nil
72        }
73        if let error = audioError1 {
74            print("Error (error.localizedDescription)")
75        }
76        
77        var audioError2:NSError?
78        do{
79            audioPlayer2 = try AVAudioPlayer(contentsOf: audioUrl2)
80        } catch let error as NSError {
81            audioError2 = error
82            audioPlayer2 = nil
83        }
84        if let error = audioError2 {
85            print("Error (error.localizedDescription)")
86        }
87        
88        audioPlayer1.delegate = self as? AVAudioPlayerDelegate
89        audioPlayer1.prepareToPlay()
90        audioPlayer2.delegate = self as? AVAudioPlayerDelegate
91        audioPlayer2.prepareToPlay()
92    }
93    
94   
95    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
96       guard let touchLocation = touches.first?.location(in: sceneView),
97        let hitResults = sceneView.hitTest(touchLocation, options: [:]).first else  { return }
98        
99        let node = hitResults.node
100        
101        if node.name == "node1" {
102            
103            audioPlayer1.play()
104            
105        } else if node.name == "node2" {
106            
107            audioPlayer2.play()
108        
109        }
110    }
111    
112    override func viewWillAppear(_ animated: Bool) {
113        super.viewWillAppear(animated)
114        
115        let configuration = ARWorldTrackingConfiguration()
116
117        sceneView.session.run(configuration)
118        
119    }
120    
121    override func viewWillDisappear(_ animated: Bool) {
122        super.viewWillDisappear(animated)
123        
124        // Pause the view's session
125        sceneView.session.pause()
126    }
127}
128

試したこと

オブジェクトを1つ配置し、音が再生されるといったコードは以下になります。

swift
1import UIKit
2import SceneKit
3import ARKit
4import AVFoundation
5
6
7class ViewController: UIViewController, ARSCNViewDelegate {
8
9    @IBOutlet var sceneView: ARSCNView!
10    let node1 = SCNNode()
11    var audioPlayer1:AVAudioPlayer!
12    
13    override func viewDidLoad() {
14        super.viewDidLoad()
15        
16        // Set the view's delegate
17        sceneView.delegate = self
18       // sceneView.debugOptions = [.showWorldOrigin, .showFeaturePoints]
19        
20       // let node1 = SCNNode()
21        //node.geometry = SCNBox(width: 1, height: 1, length: 1, chamferRadius: 0)
22        node1.geometry = SCNSphere(radius: 1)
23        let marerial1 = SCNMaterial()
24        marerial1.diffuse.contents = UIColor(red: 255/255, green: 0/255, blue: 0/255, alpha: 1.0)
25        node1.geometry?.materials = [marerial1]
26 
27        let phi1:Double = 252.292
28        let PHI1:Double = phi1 * (.pi/180)
29        let theta1:Double = 69.663
30        let THETA1:Double = theta1 * (.pi/180)
31             
32        let r:Double = 100
33        
34        let x1:Double = r * sin(PHI1) * cos(THETA1)
35        let y1:Double = r * sin(THETA1) * sin(PHI1)
36        let z1:Double = r * cos(THETA1)
37        
38        node1.position = SCNVector3(Double(y1), Double(z1), -Double(x1))
39        sceneView.scene.rootNode.addChildNode(node1)
40        
41        let audioPath1 = Bundle.main.path(forResource: "sheep-cry1", ofType:"mp3")!
42        let audioUrl1 = URL(fileURLWithPath: audioPath1)
43        
44        var audioError:NSError?
45        do{
46            audioPlayer1 = try AVAudioPlayer(contentsOf: audioUrl1)
47        } catch let error as NSError {
48            audioError = error
49            audioPlayer1 = nil
50        }
51        if let error = audioError {
52            print("Error (error.localizedDescription)")
53        }
54        
55        audioPlayer1.delegate = self as? AVAudioPlayerDelegate
56        audioPlayer1.prepareToPlay()
57    }
58    
59    @IBAction func tap(_ sender: UITapGestureRecognizer) {
60        
61        let sceneView = sender.view as!ARSCNView
62        let touchLocation = sender.location(in: sceneView)
63        let hitResults = sceneView.hitTest(touchLocation, options: [:])
64        
65        if !hitResults.isEmpty {
66            audioPlayer1.play()
67        }
68        else {
69            audioPlayer1.stop()
70        }
71    }
72    
73    override func viewWillAppear(_ animated: Bool) {
74        super.viewWillAppear(animated)
75        
76        let configuration = ARWorldTrackingConfiguration()
77
78        sceneView.session.run(configuration)
79        
80    }
81    
82    override func viewWillDisappear(_ animated: Bool) {
83        super.viewWillDisappear(animated)
84        
85        // Pause the view's session
86        sceneView.session.pause()
87    }    
88}
89