How to cut random holes in SKSpriteNodes

Question

Aside from the fact that the question asked here : Draw a hole in a rectangle with SpriteKit? has not satisfactorily been answered in its own right, the most significant dif

Answer 1

In my total honesty, I'm not really sure to understand deeply what do you want to achieve, but I can try to answer to this question:

..cutting random circles out of each slice of cheese?

In this project I've try to re-build a typical rectangle (the piece of cheese) with random holes, then I've extract these holes and collect them to an array.

import SpriteKit
class GameScene: SKScene {
    struct Cheese
    {
        static let color1 = SKColor(red: 255/255, green: 241/255, blue: 173/255, alpha: 1)
        static let color2 = SKColor(red: 255/255, green: 212/255, blue: 0/255, alpha: 1)
        static let color3 = SKColor(red: 204/255, green: 170/255, blue: 0/255, alpha: 1)
        static let color4 = SKColor(red: 140/255, green: 116/255, blue: 0/255, alpha: 1)
    }
    let cheeseColor = [Cheese.color1,Cheese.color2,Cheese.color3,Cheese.color4]
    override func didMove(to view: SKView) {        
        let totHoles = randomNumber(range:4...8)
        let color = randomNumber(range:0...3)
        let cheeseCropNode = makeCheese(size: CGSize(width:400,height:200),color: cheeseColor[color], totHoles:totHoles)
        cheeseCropNode.position = CGPoint(x:0,y:-50)
        addChild(cheeseCropNode)
        // Start to collect and show holes
        var holes = [SKNode]()
        var counter = 1
        let _ = cheeseCropNode.enumerateChildNodes(withName: "//hole*", using:{ node, stop in
            // node is the hole
            let pos = self.convert(node.position, from: cheeseCropNode)
            let sprite = SKSpriteNode.init(color: .red, size: node.frame.size)
            sprite.position = pos

            //Remove these shapes, it's just to debug
            let shape = SKShapeNode.init(rect: sprite.frame)
            shape.strokeColor = .red
            self.addChild(shape)
            // -- end to remove

            let holeTxt = SKView().texture(from: cheeseCropNode, crop: sprite.frame)
            let hole = SKSpriteNode.init(texture: holeTxt)
            hole.position = CGPoint(x:-(self.frame.maxX)+(100*CGFloat(counter)),y:150)
            hole.name = node.name
            self.addChild(hole)
            holes.append(hole)
            counter += 1
        })
    }

    func randomNumber(range: ClosedRange = 1...6) -> Int {
        let min = range.lowerBound
        let max = range.upperBound
        return Int(arc4random_uniform(UInt32(1 + max - min))) + min
    }
    func randomCGFloat(min: CGFloat, max: CGFloat) -> CGFloat {
        return (CGFloat(arc4random()) / CGFloat(UINT32_MAX)) * (max - min) + min
    }
    func makeCheese(size:CGSize , color:SKColor, totHoles:Int)->SKCropNode {
        let cropNode = SKCropNode()
        let cheese = SKSpriteNode.init(color: color, size: size)
        for i in 0..

Result:

P.S. Don't pay attention to red rectangles, it's just to show you the holes:

If you want the exactly reversed hole, (the negative image), you could use SKCropNode with the hole.blendMode, for example:

Substitute this part of the code:

// -- end to remove

                let holeTxt = SKView().texture(from: cheeseCropNode, crop: sprite.frame)
                let hole = SKSpriteNode.init(texture: holeTxt)
                hole.position = CGPoint(x:-(self.frame.maxX)+(100*CGFloat(counter)),y:150)
                hole.name = node.name
                self.addChild(hole)
                holes.append(hole)
                counter += 1

with this part:

// -- end to remove

            let holeTxt = SKView().texture(from: cheeseCropNode, crop: sprite.frame)
            let hole = SKSpriteNode.init(texture: holeTxt)
            hole.position = CGPoint(x:-(self.frame.maxX)+(100*CGFloat(counter)),y:150)
            hole.name = node.name

            let negativeCropHole = SKCropNode()
            let shadow = SKShapeNode.init(rect: hole.frame)
            shadow.fillColor = (node as! SKShapeNode).fillColor
            shadow.strokeColor = SKColor.clear
            hole.blendMode = .subtract
            negativeCropHole.addChild(shadow)
            negativeCropHole.maskNode = shadow
            negativeCropHole.addChild(hole)
            negativeCropHole.name = hole.name
            self.addChild(negativeCropHole)
            holes.append(negativeCropHole)
            counter += 1

Result (another example):

Hope these example and this code help you to obtain your objectives, I've used rectangles to make masks but your could create CGPaths if you need.