如何快速将scnode mask更改为图像4？

Question

我遇到一个问题，我的屏幕上显示的scnode中有浮动蒙版。但是，我不想显示该浮动蒙版，而是希望显示以下图像。谁能帮我解决这个问题。

图片：https://imgur.com/a/sUkRcv2

这是我的代码：

      var maskNode: Mask?

    override func viewDidLoad() {
        super.viewDidLoad()

        self.sceneView.backgroundColor = .clear
        self.sceneView.scene = SCNScene()
        self.sceneView.rendersContinuously = true



        if let device = MTLCreateSystemDefaultDevice(),
        let geo = ARSCNFaceGeometry(device: device) {


            self.maskNode = Mask(geometry: geo)
            self.sceneView.scene?.rootNode.addChildNode(self.maskNode!)
            self.maskNode?.position = SCNVector3(x: 0.0, y: 0.0, z: 0.0)


        } 

面具：

import ARKit
import SceneKit

class Mask: SCNNode, VirtualFaceContent {

    init(geometry: ARSCNFaceGeometry) {



        let material = SCNMaterial()
        material.diffuse.contents = #colorLiteral(red: 1, green: 1, blue: 1, alpha: 1)
        geometry.firstMaterial = material





         super.init()
        self.geometry = geometry

    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("\(#function) has not been implemented")
    }




    func update(withFaceAnchor anchor: ARFaceAnchor) {
        let faceGeometry = geometry as! ARSCNFaceGeometry
        faceGeometry.update(from: anchor.geometry)
    }
}