CODEX

How to Generate Lightning in Swift [Recursively]

Generate realistic-looking lightning strikes in Swift

Learn how to generate realistic lightning in Swift.

Disclaimer: This post contains affiliate links.

The Setup

To get started, create a Game App in Xcode. Remove Actions.sks file and remove the hello label from GameScene.sks. Then erase excess code in GameScene.swift file to make it look like this:

import SpriteKit
import GameplayKit
class GameScene: SKScene {
    override func didMove(to view: SKView) {
        self.backgroundColor = .black
    }
}

Drawing a Single Line

A lightning strike consists of small paths or line segments that are connected to form the lightning strike.

First off, we want to be able to draw a line from point A to point B. The following code snippet will return a line:

func createLine(pointA: CGPoint, pointB: CGPoint) -> SKShapeNode {
    let pathToDraw = CGMutablePath()
    pathToDraw.move(to: pointA)
    pathToDraw.addLine(to: pointB)
    let line = SKShapeNode()
    line.path = pathToDraw
    line.glowWidth = 1
    line.strokeColor = .white
    return line
}