giln

import ARKit
import SceneKit

public class PlaneNode: SCNNode {

    // MARK: - Public functions

    public func update(from planeAnchor: ARPlaneAnchor) {
        // We need to create a new geometry each time because it does not seem to update correctly for physics
        guard let device = MTLCreateSystemDefaultDevice(),

giln

// MARK: - ARSCNViewDelegate

func renderer(_: SCNSceneRenderer, nodeFor anchor: ARAnchor) -> SCNNode? {
    guard let _ = anchor as? ARPlaneAnchor else { return nil }

    // We return a special type of SCNNode for ARPlaneAnchors
    return PlaneNode()
}

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

giln

import SceneKit

public class BallNode: SCNNode {
    // MARK: - Lifecycle

    public convenience init(radius: CGFloat) {
        self.init()
        let sphere = SCNSphere(radius: radius)

        // We create a Physically Based Rendering material

giln

// MARK: - Actions

@objc func viewDidTap(recognizer: UITapGestureRecognizer) {
    // We get the tap location as a 2D Screen coordinate
    let tapLocation = recognizer.location(in: sceneView)

    // To transform our 2D Screen coordinates to 3D screen coordinates we use hitTest function
    let hitTestResults = sceneView.hitTest(tapLocation, types: .existingPlaneUsingExtent)

    // We cast a ray from the point tapped on screen, and we return any intersection with existing planes

giln

public func update(from planeAnchor: ARPlaneAnchor) {
    // We need to create a new geometry each time because it does not seem to update correctly for physics
    guard let device = MTLCreateSystemDefaultDevice(),
        let geom = ARSCNPlaneGeometry(device: device) else {
            fatalError()
    }

    geom.firstMaterial?.diffuse.contents = UIColor.blue.withAlphaComponent(0.3)
    geom.update(from: planeAnchor.geometry)

giln

// This allows the material to be invisible but still receive shadows and perform occlusion (hide objects behind them).
let material = SCNMaterial()
material.lightingModel = .constant
material.writesToDepthBuffer = true
material.colorBufferWriteMask = []
geom.firstMaterial = material

geom.update(from: planeAnchor.geometry)

giln

import SceneKit

public class SpotlightNode: SCNNode {

    // MARK: - Lifecycle
    public override init() {
        super.init()
        commonInit()
    }

giln

import CoreVideo

extension CVPixelBuffer {
    func searchTopPoint() -> CGPoint? {
        // Get width and height of buffer
        let width = CVPixelBufferGetWidth(self)
        let height = CVPixelBufferGetHeight(self)

        let bytesPerRow = CVPixelBufferGetBytesPerRow(self)

giln

import SceneKit

public class TouchNode: SCNNode {

    // MARK: - Lifecycle

    public override init() {
        super.init()
        commonInit()
    }

giln

private func startDetection() {
// To avoid force unwrap in VNImageRequestHandler
guard let buffer = currentBuffer else { return }

handDetector.performDetection(inputBuffer: buffer) { outputBuffer, _ in
    // Here we are on a background thread
    var previewImage: UIImage?
    var normalizedFingerTip: CGPoint?

    defer {