ARKit 如何在没有跟踪时暂停视频

Posted 2023-03-16

【中文标题】ARKit 如何在没有跟踪时暂停视频

【英文标题】：ARKit How to Pause video when out of tracking

【发布时间】：2019-03-21 13:50:12

【问题描述】：

我正在使用 ARKit 将视频放在跟踪的图像上。

问题是当我不跟踪图像时，视频仍然在播放，声音也在播放。

当我不跟踪图像时，有什么方法可以暂停视频吗？

func setupVideoOnNode(_ node: SCNNode, fromURL url: URL)


    var videoPlayerNode: SKVideoNode!      
    let videoPlayer = AVPlayer(url: url)

    videoPlayerNode = SKVideoNode(avPlayer: videoPlayer)
    videoPlayerNode.yScale = -1       

    let spriteKitScene = SKScene(size: CGSize(width: 1000, height: 1000))
    spriteKitScene.scaleMode = .aspectFit
    videoPlayerNode.position = CGPoint(x: spriteKitScene.size.width/2, y: spriteKitScene.size.height/2)
    videoPlayerNode.size = spriteKitScene.size
    spriteKitScene.addChild(videoPlayerNode)

    node.geometry?.firstMaterial?.diffuse.contents = spriteKitScene

    videoPlayerNode.play()

我怎样才能实现它？

感谢您的帮助。

我在下面添加了当前代码。

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

    guard let imageAnchor = anchor as? ARImageAnchor else  return 

    let referenceImage = imageAnchor.referenceImage

    let width = CGFloat(referenceImage.physicalSize.width)
    let height = CGFloat(referenceImage.physicalSize.height)


    let videoHolder = SCNNode()
    let videoHolderGeometry = SCNPlane(width: width, height: height)
    videoHolder.transform = SCNMatrix4MakeRotation(-Float.pi / 2, 1, 0, 0)
    videoHolder.geometry = videoHolderGeometry


    if let videoURL = Bundle.main.url(forResource: "img.scnassets/route", withExtension: "MOV")
        setupVideoOnNode(videoHolder, fromURL: videoURL)
    


    node.addChildNode(videoHolder)

    videoHolder.name = "route"



var videoPlayerNode: SKVideoNode?
var videoPlayer: AVPlayer?


func setupVideoOnNode(_ node: SCNNode, fromURL url: URL)

    let videoPlayer = AVPlayer(url: url)

    videoPlayerNode = SKVideoNode(avPlayer: videoPlayer)
    videoPlayerNode?.yScale = -1


    let spriteKitScene = SKScene(size: CGSize(width: 1000, height: 1000))
    spriteKitScene.scaleMode = .aspectFit
    videoPlayerNode?.position = CGPoint(x: spriteKitScene.size.width/2, y: spriteKitScene.size.height/2)
    videoPlayerNode?.size = spriteKitScene.size
    spriteKitScene.addChild(videoPlayerNode!)


    node.geometry?.firstMaterial?.diffuse.contents = spriteKitScene


    videoPlayerNode?.play()
    videoPlayer.volume = 100

    videoPlayer.actionAtItemEnd = AVPlayer.ActionAtItemEnd.none;
    NotificationCenter.default.addObserver(self,
                                           selector: #selector(self.stateEnd),
                                           name: NSNotification.Name("AVPlayerItemDidPlayToEndTimeNotification"),
                                           object: videoPlayer.currentItem)




@objc func stateEnd(notification: NSNotification) 
    let avPlayerItem = notification.object as? AVPlayerItem
    avPlayerItem?.seek(to: CMTime.zero)


func session(_ session: ARSession, didUpdate frame: ARFrame) 
    if !sceneView.isNode(videoPlayerNode, insideFrustumOf: sceneView!.pointOfView) 
        videoPlayerNode?.pause()
    

上述代码发生错误。

if !sceneView.isNode(videoPlayerNode, insideFrustumOf: sceneView!.pointOfView)

无法转换“SKVideoNode”类型的值？到预期的参数类型'SCNNode'

【问题讨论】：

您好，您对此有什么解决方案吗？我也卡在那里了。

你好，还没有。您是否尝试过以下答案？

【参考方案1】：

如果你符合ARSessionDelegate，你可以使用func session(ARSession, didUpdate: ARFrame) ，与isNode(_:insideFrustumOf:)一起检查视频节点是否在帧中，每帧，如果不是则暂停。

var videoPlayerNode: SKVideoNode?      
var videoPlayer: AVPlayer?

func setupVideoOnNode(_ node: SCNNode, fromURL url: URL)

    videoPlayer = AVPlayer(url: url)

    videoPlayerNode = SKVideoNode(avPlayer: videoPlayer)
    videoPlayerNode?.yScale = -1       

    let spriteKitScene = SKScene(size: CGSize(width: 1000, height: 1000))
    spriteKitScene.scaleMode = .aspectFit
    videoPlayerNode?.position = CGPoint(x: spriteKitScene.size.width/2, y: spriteKitScene.size.height/2)
    videoPlayerNode?.size = spriteKitScene.size
    spriteKitScene.addChild(videoPlayerNode!)

    node.geometry?.firstMaterial?.diffuse.contents = spriteKitScene

    videoPlayerNode?.play()



func session(_ session: ARSession, didUpdate frame: ARFrame) 
    if !sceneView.isNode(videoPlayerNode, insideFrustumOf: sceneView!.pointOfView) 
        videoPlayerNode?.pause()
    

【讨论】：

非常感谢您的评论！我正在努力充分利用您的建议，但是我无法解决下一行的问题。 if !sceneView.isNode(videoPlayerNode, insideFrustumOf: sceneView!.pointOfView) 无法转换类型“SKVideoNode？”的值到预期的参数类型 'SCNNode' 感谢您的帮助！

【参考方案2】：

试试这个：

override func viewWillDisappear(_ animated: Bool) 
    super.viewWillDisappear(animated)

    // Pause the view's session
    sceneView.session.pause()