ARWorkshop 3 Grafitti in 3D

VieController.swift

//
//  ViewController.swift
//  helloARAppWorkshop2
//
//  Created by Chris Jungmann on 6/17/20.
//  Copyright © 2020 Chris Jungmann. All rights reserved.
//

import UIKit
import SceneKit
import ARKit


class ViewController: UIViewController, ARSCNViewDelegate {

    @IBOutlet var sceneView: ARSCNView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // Set the view's delegate
        sceneView.delegate = self
        
        // Show statistics such as fps and timing information
        sceneView.showsStatistics = true
        
        // Create a new scene
        // let scene = SCNScene(named: "art.scnassets/ship.scn")!
    
        // Set the scene to the view
        // sceneView.scene = scene
           
        sceneView.autoenablesDefaultLighting = true
        
    }
    
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        
        // Create a session configuration
        let configuration = ARWorldTrackingConfiguration()

        self.sceneView.debugOptions = [ARSCNDebugOptions.showFeaturePoints, ARSCNDebugOptions.showWorldOrigin]

        // Run the view's session
        sceneView.session.run(configuration)
    }
    
    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        
        // Pause the view's session
        sceneView.session.pause()
    }
    
    
    @IBAction func addSomething(_ sender: Any) {
        
        // self.addSimpleShapes()
    }
    
    @IBOutlet weak var touchButton: UIButton!
    
    // MARK: - Workshop III
    

    // MARK: - Utilities

    func randomNumber(minValue: CGFloat, maxValue: CGFloat) -> CGFloat {
        return CGFloat(arc4random()) / CGFloat(UINT32_MAX) * abs(minValue - maxValue) + min(minValue, maxValue)
    }
    
    
    
    // MARK: - ARSCNViewDelegate
    
/*
    // Override to create and configure nodes for anchors added to the view's session.
    func renderer(_ renderer: SCNSceneRenderer, nodeFor anchor: ARAnchor) -> SCNNode? {
        let node = SCNNode()
     
        return node
    }
*/
    
    func renderer(_ renderer: SCNSceneRenderer, willRenderScene scene: SCNScene, atTime time: TimeInterval) {
        
        print("Will render")
        
        guard let pointOfView = sceneView.pointOfView else {return}
        
        let transform = pointOfView.transform
        let orientation = SCNVector3(-transform.m31, -transform.m32, -transform.m33)
        let location =  SCNVector3(transform.m41, transform.m42, transform.m43)
        let cameraOrientationAndLocation = orientation + location
        
        print(cameraOrientationAndLocation)
        
        DispatchQueue.main.async {

            if self.touchButton.isHighlighted {

                let sphereNode = SCNNode(geometry: SCNSphere(radius: 0.01))
                sphereNode.position = cameraOrientationAndLocation
                sphereNode.geometry?.firstMaterial?.diffuse.contents = UIColor.black
                sphereNode.geometry?.firstMaterial?.diffuse.intensity = 0.75

                sphereNode.geometry?.firstMaterial?.transparency = 0.45

                self.sceneView.scene.rootNode.addChildNode(sphereNode)
                
            }
            
        }
                

    }
    
    func session(_ session: ARSession, didFailWithError error: Error) {
        // Present an error message to the user
        
    }
    
    func sessionWasInterrupted(_ session: ARSession) {
        // Inform the user that the session has been interrupted, for example, by presenting an overlay
        
    }
    
    func sessionInterruptionEnded(_ session: ARSession) {
        // Reset tracking and/or remove existing anchors if consistent tracking is required
        
    }
}


postfix operator +
func +(left: SCNVector3, right: SCNVector3) -> SCNVector3 {
    return SCNVector3Make(left.x + right.x, left.y + right.y, left.z + right.z)
}