swift - 3D 定位音频——沿 Y 轴和 Z 轴移动 SCNAudioPlayer

Question

使用 SceneKit，我可以在 x 轴上从左向右移动 audioNode，但在 y 和 z 轴上移动时遇到问题。我戴着耳机，所以我可以听到双耳(3d 音频)效果。我也在 MacOS 上运行它。

我的测试代码如下。有人能让我知道我错过了什么吗？我将不胜感激!

import Cocoa
import SceneKit

class ViewController: NSViewController {

    @IBOutlet weak var sceneView: SCNView!

    override func viewDidLoad() {
        super.viewDidLoad()

        let path = Bundle.main.path(forResource: "Sounds/Test.mp3", 
                                         ofType: nil)

        let url = URL(fileURLWithPath: path!)
        let source = SCNAudioSource(url:url)!
        source.loops = true
        source.shouldStream = false
        source.isPositional = true
        source.load()

        let player = SCNAudioPlayer(source: source)
        let box = SCNBox(width: 100.0, 
                        height: 100.0, 
                        length: 100.0, 
                 chamferRadius: 100.0)
        let boxNode = SCNNode(geometry: box)
        let audioNode = SCNNode()
        boxNode.addChildNode(audioNode)

        let scene = SCNScene()
        scene.rootNode.addChildNode(boxNode)
        sceneView.scene = scene
        audioNode.addAudioPlayer(player)

        let avm = player.audioNode as! AVAudioMixing
        avm.volume = 1.0
        let up = SCNAction.moveBy(x: 0, y: 100, z: 0, duration: 5)
        let down = SCNAction.moveBy(x: 0, y: -100, z: 0, duration: 5)
        let sequence = SCNAction.sequence([up, down])
        let loop = SCNAction.repeatForever(sequence)
        boxNode.runAction(loop)

        // Do any additional setup after loading the view.
    }
}

Answer 1

已更新。

您正在将 player.audioNode 转换为 AVAudioMixing 协议(protocol):

let avm = player.audioNode as! AVAudioMixing

但是您必须将它转换为一个类，而不是它。代码如下所示:

let avm = player.audioNode as? AVAudioEnvironmentNode

Any node that conforms to the AVAudioMixing protocol (for example, AVAudioPlayerNode) can act as a source in this environment. The environment has an implicit listener. By controlling the listener’s position and orientation, the application controls the way the user experiences the virtual world. This node also defines properties for distance attenuation and reverberation that help characterize the environment.

And take into account !

Only inputs with a mono channel connection format to the environment node are spatialized. If the input is stereo, the audio is passed through without being spatialized. Inputs with connection formats of more than two channels aren't supported.

当然，您需要实现 AVAudio3DMixing协议(protocol)。

这是一个工作代码:

import SceneKit
import AVFoundation

class ViewController: NSViewController, AVAudio3DMixing {

    // YOU NEED MONO AUDIO !!!

    var renderingAlgorithm = AVAudio3DMixingRenderingAlgorithm.sphericalHead
    var rate: Float = 0.0
    var reverbBlend: Float = 0.5
    var obstruction: Float = -100.0
    var occlusion: Float = -100.0
    var position: AVAudio3DPoint = AVAudio3DPoint(x: 0, y: 0, z: -100)

    override func viewDidLoad() {
        super.viewDidLoad()            
        let scene = SCNScene()

        let cameraNode = SCNNode()
        cameraNode.camera = SCNCamera()
        cameraNode.camera?.zFar = 200
        cameraNode.position = SCNVector3(x: 0, y: 0, z: 40)
        scene.rootNode.addChildNode(cameraNode)

        let sceneView = self.view as! SCNView
        sceneView.scene = scene
        sceneView.backgroundColor = NSColor.black
        sceneView.autoenablesDefaultLighting = true

        let path = Bundle.main.path(forResource: "Test_Mono", ofType: "mp3")
        let url = URL(fileURLWithPath: path!)
        let source = SCNAudioSource(url: url)!
        source.loops = true
        source.shouldStream = false  // MUST BE FALSE
        source.isPositional = true
        source.load()

        let player = SCNAudioPlayer(source: source)
        let audioNode = SCNNode()

        let box = SCNBox(width: 1, height: 1, length: 1, chamferRadius: 0.2)
        let boxNode = SCNNode(geometry: box)

        boxNode.addChildNode(audioNode)
        scene.rootNode.addChildNode(boxNode)

        audioNode.addAudioPlayer(player)
        let avm = player.audioNode as? AVAudioEnvironmentNode
        avm?.reverbBlend = reverbBlend
        avm?.renderingAlgorithm = renderingAlgorithm
        avm?.occlusion = occlusion
        avm?.obstruction = obstruction

        let up = SCNAction.moveBy(x: 0, y: 0, z: 70, duration: 5)
        let down = SCNAction.moveBy(x: 0, y: 0, z: -70 , duration: 5)
        let sequence = SCNAction.sequence([up, down])
        let loop = SCNAction.repeatForever(sequence)
        boxNode.runAction(loop)

        avm?.position = AVAudio3DPoint(
                 x: Float(boxNode.position.x),
                 y: Float(boxNode.position.y),
                 z: Float(boxNode.position.z))
    }
}