在ARKit中使用SKVideoNode来播放视频可以通过以下步骤实现：

1. 导入必要的框架：

import ARKit
import SpriteKit
import AVFoundation

2. 创建一个SKVideoNode对象和一个AVPlayer对象：

let videoURL = Bundle.main.url(forResource: "video", withExtension: "mp4")!
let player = AVPlayer(url: videoURL)
let videoNode = SKVideoNode(avPlayer: player)

3. 将SKVideoNode添加到一个SKScene中，并设置它的大小和位置：

let scene = SKScene(size: CGSize(width: 1024, height: 768))
scene.addChild(videoNode)
videoNode.position = CGPoint(x: scene.size.width/2, y: scene.size.height/2)
videoNode.size = scene.size

4. 将SKScene设置为ARSKView的场景：

let arView = ARSKView(frame: view.bounds)
arView.delegate = self
arView.presentScene(scene)

5. 在ARSessionDelegate的会话更新回调方法中，为SKVideoNode设置适当的尺寸和角度：

func session(_ session: ARSession, didUpdate frame: ARFrame) {
    guard let camera = sceneView.pointOfView else { return }
    let transform = camera.transform
    let position = SCNVector3(transform.columns.3.x, transform.columns.3.y, transform.columns.3.z)
    
    videoNode.position = CGPoint(x: position.x, y: position.y)
    videoNode.size = CGSize(width: frame.camera.imageResolution.width, height: frame.camera.imageResolution.height)
    videoNode.zRotation = CGFloat(-atan2f(transform.columns.0.z, transform.columns.0.x))
}

6. 在ARSession的配置中启用videoTexture：

let configuration = ARWorldTrackingConfiguration()
configuration.isLightEstimationEnabled = true
configuration.videoFormat = ARWorldTrackingConfiguration.supportedVideoFormats[0]
arView.session.run(configuration)

这样就可以在ARKit中使用SKVideoNode来播放视频了。