How to change ARKit node to something different - ios

Question

I need some help to implement a custom node into my ARKit scene. I am using ARSCNFaceGeometry for a mask node to move around. I need some help to implement a custom image or a node rather than using Apple's mask node. Thank you for your help.
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)
self.maskNode?.isHidden = true
}
let config = ARFaceTrackingConfiguration()
config.worldAlignment = .gravity
session.delegate = self
session.run(config, options: [])
self.updateUI()
}
Mask:
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")
}
// MARK: VirtualFaceContent
/// - Tag: SCNFaceGeometryUpdate
func update(withFaceAnchor anchor: ARFaceAnchor) {
let faceGeometry = geometry as! ARSCNFaceGeometry
faceGeometry.update(from: anchor.geometry)
}
}
VirtualFaceContent:
protocol VirtualFaceContent {
func update(withFaceAnchor: ARFaceAnchor)
}
typealias VirtualFaceNode = VirtualFaceContent & SCNNode
// MARK: Loading Content
func loadedContentForAsset(named resourceName: String) -> SCNNode {
let url = Bundle.main.url(forResource: resourceName, withExtension: "scn", subdirectory: "Models.scnassets")!
let node = SCNReferenceNode(url: url)!
node.load()
return node
}

Answer 1

You can use renderer(node: for anchor:). Guard check if the anchor is an ARFaceAnchor and then assign your custom geometry to that node. You can also just add your custom node to the node ARKit added for the anchor, up to you.