Background snippet for spritekit

background.swift

import UIKit
import SpriteKit

class gameScene: SKScene {
    var background = SKSpriteNode(imageNamed: "bgimage")

    override func sceneDidLoad(view: SKView) {
        background.position  = CGPoint(x: frame.size.width / 2, y: frame.size.height / 2)
        background.zPosition = -1;
        addChild(background)
    }
    
    ...
    
}