DGArt Scenekit Playgrounds mini Game Tutorial 3

// Sample provide from www.nitrio.com for DGArt iPad 
import SwiftUI
import SceneKit

struct ContentView: View {
    
    var body: some View { 
        VStack { 
            GameViewControllerRepresentable()
            VStack {
                Text("DGArt Mini Game | Star")
            }.padding(10)
        }
    }
}

struct GameViewControllerRepresentable: UIViewControllerRepresentable {
    func makeUIViewController (context: Context) -> GameViewController {
        GameViewController ()
    }
    
    func updateUIViewController(_ uiViewController: GameViewController, context: Context) {
        
    }
}

// Sample provide from www.nitrio.com for DGArt iPad 
import UIKit
import SceneKit 

public class GameViewController: UIViewController {
    
    private var scene: SCNScene!
    private var sceneView = SCNView()
    
    private var screenSize = CGSize(width: 500, height: 1200)
    
    public override func viewDidLoad() {
        super.viewDidLoad ()
        setup()
    }
    
    func setup () {
        sceneView.frame = CGRect (origin: .zero, size: screenSize)
        scene = SCNScene(named: "Star.scn")
        
        // set scene background color
        scene?.background.contents = UIColor.init(red: 0.1, green: 0.1, blue: 0.2, alpha: 1.0)
        
        // load star
        let star = (scene?.rootNode.childNode(withName: "Star", recursively: true))!
        star.position = SCNVector3(x: 0, y: -10, z: -5)
        star.scale = SCNVector3(x: 0.4, y: 0.4, z: 0.4)
        
        // clone star
        let star1 = star.clone()
        scene?.rootNode.addChildNode(star1)
        
        let star2 = star.clone()
        scene?.rootNode.addChildNode(star2)
        
        let star3 = star.clone()
        scene?.rootNode.addChildNode(star3)
        
        let star4 = star.clone()
        scene?.rootNode.addChildNode(star4)
        
        // gen and animate Stars
        scene?.rootNode.childNodes.filter({ $0.name!.contains("Star") }).forEach({ 
            self.genStarLocation($0)
        })
        
        // Add Ground
        let box = SCNBox(width: 50, height: 0.1, length: 50, chamferRadius: 0)
        box.materials[0].diffuse.contents = UIColor.black
        let boxNode = SCNNode(geometry: box)
        boxNode.position = SCNVector3(0, -3, 0)
        scene?.rootNode.addChildNode(boxNode)
        
        // Add Light
        let myLight = SCNNode()
        myLight.light = SCNLight()
        myLight.position = SCNVector3(x: -5, y: 10, z: 10)
        myLight.look(at: SCNVector3(x: 0, y: 0, z: 0))
        myLight.light?.intensity = 800
        myLight.light?.type = SCNLight.LightType.directional
        myLight.light?.color = UIColor.white
        myLight.light?.castsShadow = true
        scene?.rootNode.addChildNode(myLight)
        
        
        // Add Camera
        let cameraNode = SCNNode()
        cameraNode.camera = SCNCamera()
        cameraNode.camera?.usesOrthographicProjection = true
        cameraNode.camera?.orthographicScale = 8
        cameraNode.position = SCNVector3(x: 0, y: 10, z: 15)
        cameraNode.look(at: SCNVector3(x: 0, y: 0, z: 0))
        
        sceneView.scene = scene
        sceneView.pointOfView = cameraNode
        sceneView.autoenablesDefaultLighting = true
        
        
        
        //sceneView.showsStatistics = true
        //sceneView.allowsCameraControl = true
        //sceneView.debugOptions = [.showWireframe, .showBoundingBoxes, .showPhysicsShapes]
        view.addSubview(sceneView)
    }
    
    // animate and reposition stars after move from -z to z
    func genStarLocation(_ snode: SCNNode) {
        let rand1 = randomNum(min: -3, max: 3)
        let rand2 = randomNum(min: -5, max: 5)
        let randTime = randomNum(min: 0, max: 5)
        let moveAct = SCNAction.sequence([
            SCNAction.move(to: SCNVector3(rand1, 0.0, -25.0+rand2), duration: 0.2),
            SCNAction.move(to: SCNVector3(rand1, 0.0, 20.0+rand2), duration: 6.0),
            SCNAction.move(to: SCNVector3(rand1, -10.0, 20.0+rand2), duration: 0.2),
            SCNAction.move(to: SCNVector3(rand1, -10.0, -25.0+rand2), duration: 0.2),
            SCNAction.move(to: SCNVector3(rand1, 0.0, -25.0+rand2), duration: 0.2),
            SCNAction.wait(duration: randTime),
        ])
        
        snode.runAction(moveAct, completionHandler: {
            self.genStarLocation(snode)
        })
    }
    
    func randomNum(min:Int, max:Int) -> CGFloat {
        let randomPosition = Int.random(in: min...max)
        return CGFloat(randomPosition)
    }
    
}

Finally, you will be able to see the star moving animation appear beside.

Alternatively, you can obtain the playground file here for exercise mentioned above. Download miniGameStar.swiftpm.zip