Move camera to tapped SCNNode - ios

Question

I'm using SceneKit and Swift to try and move the camera so it's 'focused' on the selected node. I understand I have the defaultCameraController enabled but I was trying to adjust the camera's position via dolly, rotate and translateInCameraSpaceBy but there was no animated transition - it just jumped to the new position.
Is there anyway for the camera to glide into position like how Google Maps slides/then zooms over to a searched location?
Any help would be greatly appreciated :)
Here's my code:
import UIKit
import SceneKit
class ViewController: UIViewController {
var gameView: SCNView!
var scene: SCNScene!
var cameraNode: SCNNode!
override func viewDidLoad() {
super.viewDidLoad()
// Scene
scene = SCNScene()
// Camera
cameraNode = SCNNode()
cameraNode.camera = SCNCamera()
cameraNode.position = SCNVector3(0, 0, 10)
scene.rootNode.addChildNode(cameraNode)
// Light
/*
let lightNode = SCNNode()
lightNode.light = SCNLight()
lightNode.light?.type = .omni
lightNode.position = SCNVector3(0, 10, 2)
scene.rootNode.addChildNode(lightNode)
*/
// Stars
//let stars = SCNParticleSystem(named: "starsParticles.scnp", inDirectory: nil)!
//scene.rootNode.addParticleSystem(stars)
// Earth
let earthNode = itemPlate()
earthNode.position = SCNVector3(0, 0, 0)
scene.rootNode.addChildNode(earthNode)
// Create orbiting moonOne
let moonNodeOne = itemPlate()
moonNodeOne.position = SCNVector3(3, 0, 0)
earthNode.addChildNode(moonNodeOne)
// Create orbiting moonOne
let moonNodeTwo = itemPlate()
moonNodeTwo.position = SCNVector3(5, 3, 2)
earthNode.addChildNode(moonNodeTwo)
// Create orbiting moonOne
let moonNodeThree = itemPlate()
moonNodeThree.position = SCNVector3(-4, -3, 5)
earthNode.addChildNode(moonNodeThree)
// Scene formation
gameView = self.view as! SCNView
gameView.scene = scene
gameView.showsStatistics = true
gameView.allowsCameraControl = true
gameView.autoenablesDefaultLighting = true
gameView.defaultCameraController.interactionMode = .fly
gameView.defaultCameraController.inertiaEnabled = true
gameView.defaultCameraController.maximumVerticalAngle = 89
gameView.defaultCameraController.minimumVerticalAngle = -89
scene.background.contents = UIImage(named: "orangeBg.jpg")
}
override var prefersStatusBarHidden: Bool {
return true
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
let touch = touches.first!
let location = touch.location(in: gameView)
let hitList = gameView.hitTest(location, options: nil)
if let hitObject = hitList.first {
let node = hitObject.node
// Update camera position
//gameView.defaultCameraController.translateInCameraSpaceBy(x: node.position.x, y: node.position.y, z: node.position.z + 5)
let onScreenPoint:CGPoint = CGPoint(x: 1.0, y: 1.0)
let viewport:CGSize = CGSize(width: 50, height: 50)
gameView.defaultCameraController.dolly(by: 1.0, onScreenPoint: onScreenPoint, viewport: viewport)
//let newCameraPosition = SCNVector3Make(node.position.x, node.position.y, node.position.z + 10)
print("NODE_HIT_OBJECT_COORDS: \(node.position.x), \(node.position.y) \(node.position.y)")
//let moveToAction = SCNAction.move(by: newCameraPosition, duration: 1.0)
}
}
}

Answer 1

You can implement in your code a methodology like this (sorry, I used macOS project instead iOS, but it's almost the same):
func handleClick(_ gestureRecognizer: NSGestureRecognizer) {
let scnView = self.view as! SCNView
let p = gestureRecognizer.location(in: scnView)
let hitResults = scnView.hitTest(p, options: [:])
if hitResults.count > 0 {
let result = hitResults[0]
let nodePosition = result.node.position.z
var matrix = matrix_identity_float4x4
SCNTransaction.begin()
SCNTransaction.animationDuration = 1.5 // duration in seconds
matrix.columns.3.z = Float(nodePosition + 5.0)
scnView.pointOfView?.position.z = CGFloat(matrix.columns.3.z)
SCNTransaction.commit()
}
}
Or, as a second logical option, you can use SceneKit's constraints:
func handleClick(_ gestureRecognizer: NSGestureRecognizer) {
let scnView = self.view as! SCNView
let p = gestureRecognizer.location(in: scnView)
let hitResults = scnView.hitTest(p, options: [:])
if hitResults.count > 0 {
let result = hitResults[0]
let nodePosition = result.node
let constraint1 = SCNLookAtConstraint(target: nodePosition)
let constraint2 = SCNDistanceConstraint(target: nodePosition)
constraint2.minimumDistance = 5
constraint2.maximumDistance = 9
SCNTransaction.begin()
SCNTransaction.animationDuration = 1.5
scnView.pointOfView?.constraints = [constraint2, constraint1]
SCNTransaction.commit()
}
}
P.S. These two approaches ain't out-of-the-box solutions but rather hints on how to implement what you want to.