SKSpriteNode hidden under a UI Background Image - ios

Question

I have an SKSpriteNode that functions properly. But when I add a UIImage, the SKSpriteNode becomes hidden behind the UIImage. I have been trying to figure out why, but I am having a little bit of trouble and can't seem to figure out what I am missing to allow the SKSSpriteNode to appear on top of the UI background Image, instead of behind it where it can't be seen. Any help would be greatly appreciated!
import UIKit
import SpriteKit
class GameViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
if let scene = GameScene(fileNamed:"GameScene") {
// Configure the view.
let skView = self.view as! SKView
skView.showsFPS = true
skView.showsNodeCount = true
/* Sprite Kit applies additional optimizations to improve rendering performance */
skView.ignoresSiblingOrder = true
/* Set the scale mode to scale to fit the window */
scene.scaleMode = .AspectFill
skView.presentScene(scene)
}
}
override func shouldAutorotate() -> Bool {
return true
}
override func supportedInterfaceOrientations() -> UIInterfaceOrientationMask {
if UIDevice.currentDevice().userInterfaceIdiom == .Phone {
return .AllButUpsideDown
} else {
return .All
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Release any cached data, images, etc that aren't in use.
}
override func prefersStatusBarHidden() -> Bool {
return true
}
}
import SpriteKit
import SceneKit
class GameScene: SKScene, SKPhysicsContactDelegate {
var blueBall:SKSpriteNode!
override func didMoveToView(view: SKView) {
self.physicsWorld.gravity = CGVectorMake(0.0, -5.0)
self.physicsWorld.contactDelegate = self
blueBall = SKSpriteNode( imageNamed: "ball")
blueBall.position = CGPoint(x: CGRectGetMidX(self.frame), y: CGRectGetMidY(self.frame))
blueBall.physicsBody = SKPhysicsBody(circleOfRadius: blueBall.size.width / 1.5 )
blueBall.physicsBody!.dynamic = true
blueBall.physicsBody!.allowsRotation = false
self.addChild(blueBall)
}
override func touchesBegan(touches: Set<UITouch> , withEvent event: UIEvent?) {
self.blueBall.physicsBody?.velocity = CGVectorMake(35, 0)
self.blueBall.physicsBody?.applyImpulse(CGVectorMake(4, 10))
}
}

Answer 1

For draw order use the zPosition property:
In your case you will need to give the Sprite you want to be displayed in front a higher .zPosition value than the one to be displayed further back.
Example: ball.zPosition = 10
zPosition definition:
The height of the node relative to its parent.
Tipps:
The default value is 0.0. The positive z axis is projected toward the viewer so that nodes with larger z values are closer to the viewer.