SpriteKit iOS Game Development

Scene Graph & Coordinate System

• Y-up coordinate system — origin (0,0) at bottom-left by default
• SKScene.anchorPoint defaults to (0.5, 0.5) — center of screen
• zPosition controls draw order — higher = in front; siblings draw in add order if equal
• Every node inherits parent's transform — build hierarchy intentionally

class GameScene: SKScene {
    override func didMove(to view: SKView) {
        backgroundColor = .black
        scaleMode = .resizeFill   // or .aspectFit for fixed-resolution games
    }
}

Physics