Access Geometry Child Node Scenekit

Question

I am trying to access the childnode: boxNode, and then rotate the node using the input from a pan gesture recognizer. How should I access this node so I can manipulate it? Should I declare the cube node in a global scope and modify that way? I am new to Swift so I apologize if this code looks sloppy. I would like to add rotation actions inside of my panGesture() function. Thanks!

import UIKit
import SceneKit

class GameViewController: UIViewController {

var scnView: SCNView!
var scnScene: SCNScene!

override func viewDidLoad() {
    super.viewDidLoad()
    setupView()
    setupScene()
}

//  override var shouldAutorotate: Bool {
//    return true
//  }
//
//  override var prefersStatusBarHidden: Bool {
//    return true
//  }

func setupView() {
    scnView = self.view as! SCNView
}

func setupScene() {
    scnScene = SCNScene()
    scnView.scene = scnScene
    scnView.backgroundColor = UIColor.blueColor()
    initCube()
    initLight()
    initCamera()
}

func initCube () {
    var cubeGeometry:SCNGeometry
    cubeGeometry = SCNBox(width: 1.0, height: 1.0, length: 1.0, chamferRadius: 0.0)
    let boxNode = SCNNode(geometry: cubeGeometry)
    scnScene.rootNode.addChildNode(boxNode)
}

func initLight () {
    let light = SCNLight()
    light.type = SCNLightTypeAmbient
    let lightNode = SCNNode()
    lightNode.light = light
    light.castsShadow = false
    lightNode.position = SCNVector3(x: 1.5, y: 1.5, z: 1.5)
    scnScene.rootNode.addChildNode(lightNode)
}

func initCamera () {
    let camera = SCNCamera()
    let cameraNode = SCNNode()
    cameraNode.camera = camera
    cameraNode.position = SCNVector3(x: 0.0, y: 0.0, z: 5.0)
    scnScene.rootNode.addChildNode(cameraNode)
}

func initRecognizer () {
    let panTestRecognizer = UIPanGestureRecognizer(target: self, action: #selector(GameViewController.panGesture(_:)))
    scnView.addGestureRecognizer(panTestRecognizer)
}

//TAKE GESTURE INPUT AND ROTATE CUBE ACCORDINGLY
func panGesture(sender: UIPanGestureRecognizer) {
    //let translation = sender.translationInView(sender.view!)
}

}

Answer 1

First of all you should update your Xcode. It looks like this is an older Swift version you are using. SCNLightTypeAmbient is .ambient in Swift 3.

So the way you should go is by giving your nodes names to identify them:

myChildNode.name = "FooChildBar"

and then you can call on your parent node

let theNodeYouAreLookingFor = parentNode.childNode(withName: "FooChildBar", recursively: true)

You can also use this on your scene's root node

let theNodeYouAreLookingFor = scene.rootNode.childNode(withName: "FooChildBar", recursively: true)

which will look at all nodes in your scene and return the one that you gave the name.