Как добавить падающие снежинки (снег, анимированные снежинки) в проект - Swift 5

lazy var bg: UIImageView = {
let bg = UIImageView(frame: view.frame)
bg.image = UIImage(named: "NY2")
bg.contentMode = .scaleAspectFill
return bg
}()

override func viewDidLoad() {
super.viewDidLoad()
       
view.addSubview(bg)
guruSnow()
}

func guruSnow() {

let emitterCell = CAEmitterCell()

emitterCell.contents = UIImage(named: "snow")?.cgImage

emitterCell.scale = 0.02
emitterCell.scaleRange = 0.6
emitterCell.emissionRange = .ulpOfOne
emitterCell.lifetime = 50.0
emitterCell.birthRate = 4
emitterCell.velocity = -30
emitterCell.velocityRange = -20
emitterCell.yAcceleration = 30
emitterCell.xAcceleration = 5
emitterCell.spin = -0.5
emitterCell.spinRange = 1.0

let snowEmitterLayer = CAEmitterLayer()
snowEmitterLayer.emitterPosition = CGPoint(x: view.bounds.width / 2, y: -50)
snowEmitterLayer.emitterSize = CGSize(width: view.bounds.width, height: 0)
snowEmitterLayer.emitterShape = kCAEmitterLayerLine
snowEmitterLayer.beginTime = CACurrentMediaTime()
snowEmitterLayer.timeOffset = 310
snowEmitterLayer.emitterCells = [emitterCell]

bg.layer.addSublayer(snowEmitterLayer)
}

Изучайте Свифт на практических примерах подробнее