swift – SceneKit SCNSceneRendererDelegate – 未调用渲染器函

我最近问了一个有一个非常明显答案的 question.我还在研究同一个项目并遇到另一个问题.我需要实现每帧逻辑,并且SCNSceneRendererDelegate协议在iOS上工作得很好,但在OSX上,渲染器函数没有触发.我创建了一个示例项目来说明我的问题.它由storyboard中的Scene Kit视图和ViewController类中的以下代码组成：

import Cocoa
import SceneKit

class ViewController: NSViewController,SCNSceneRendererDelegate {

    @IBOutlet weak var sceneView: SCNView!

    let cubeNode = SCNNode()

    override func viewDidLoad() {

        super.viewDidLoad()

        let scene = SCNScene()

        let sphere = SCNSphere(radius: 0.1)
        sphere.firstMaterial!.diffuse.contents = NSColor.yellowColor()
        let sphereNode = SCNNode(geometry: sphere)
        scene.rootNode.addChildNode(sphereNode)

        let cube = SCNBox(width: 0.2,height: 0.2,length: 0.2,chamferRadius: 0)
        cube.firstMaterial!.diffuse.contents = NSColor.greenColor()
        cubeNode.geometry = cube
        cubeNode.position = SCNVector3(1,0)
        scene.rootNode.addChildNode(cubeNode)

        let cameraNode = SCNNode()
        cameraNode.camera = SCNCamera()
        cameraNode.position = SCNVector3(2,1,2)
        let constraint = SCNLookAtConstraint(target: cubeNode)
        cameraNode.constraints = [constraint]
        scene.rootNode.addChildNode(cameraNode)

        sceneView.scene = scene
        sceneView.backgroundColor = NSColor(red: 0.5,green: 0,blue: 0.3,alpha: 1)
        sceneView.allowsCameraControl = true

        sceneView.delegate = self
        sceneView.playing = true

    }

    func renderer(renderer: SCNSceneRenderer,updateAtTime time: NSTimeInterval) {
        cubeNode.position.x += 0.1
    }
}

我想要的只是基本上每帧移动立方体.但没有任何反应.奇怪的是,当我将sceneView.allowsCameraControl设置为true时,每当我在屏幕上单击或拖动时都会调用渲染器函数(这是有意义的,因为它需要根据摄像机角度更新视图).但我希望每一帧都能调用它.

是否有错误我没看到或者这是我的Xcode中的错误？

编辑：
我已经尝试按照下面的答案中的说明,现在有ViewController的以下代码：

import Cocoa
import SceneKit

class ViewController: NSViewController {

    @IBOutlet weak var sceneView: SCNView!
    let scene = MyScene(create: true)

    override func viewDidLoad() {

        super.viewDidLoad()

        sceneView.scene = scene
        sceneView.backgroundColor = NSColor(red: 0.5,alpha: 1)
        sceneView.allowsCameraControl = true

        sceneView.delegate = scene
        sceneView.playing = true

    }

}

和MyScene课程：

import Foundation
import SceneKit

final class MyScene: SCNScene,SCNSceneRendererDelegate {

    let cubeNode = SCNNode()

    convenience init(create: Bool) {
        self.init()

        let sphere = SCNSphere(radius: 0.1)
        sphere.firstMaterial!.diffuse.contents = NSColor.yellowColor()
        let sphereNode = SCNNode(geometry: sphere)
        rootNode.addChildNode(sphereNode)

        let cube = SCNBox(width: 0.2,0)
        rootNode.addChildNode(cubeNode)

        let cameraNode = SCNNode()
        cameraNode.camera = SCNCamera()
        cameraNode.position = SCNVector3(2,2)
        let constraint = SCNLookAtConstraint(target: cubeNode)
        cameraNode.constraints = [constraint]

        rootNode.addChildNode(cameraNode)
    }

    @objc func renderer(aRenderer: SCNSceneRenderer,updateAtTime time: NSTimeInterval) {
        cubeNode.position.x += 0.01
    }
}

但是,它仍然无法正常工作.我究竟做错了什么？

编辑：设置sceneView.loops = true修复了描述的问题