Northern Lights

// By Roni Kaufman

// Inspired by Sol LeWitt's "Squiggly Brushstrokes"

​

let particles = [];

let n = 1000;

let colors;

let squiggliness = 1/800;

​

function setup() {

  createCanvas(1500, 2500);

  //colorMode(HSB, 100);

  noStroke();

  let alpha = 25;

  colors = [color(0, 255, 187, alpha), color(179, 222, 147, alpha), color(1, 80, 97, alpha), color(53, 227, 241, alpha), color(115, 78, 164, alpha)];

  background(29, 35, 61);

  updateParticles();

  setInterval(updateParticles, 2500);

}

​

function draw() {

  for (let p of particles) {

    p.draw();

    p.move();

  }

}

​

function updateParticles() {

  particles = [];

  for (let i = 0; i < n; i++) {

    let x_ = random(-50, width + 50);

    let y_ = random(-50, height + 50);

    let s_ = 0.5;

    let c_ = random(colors);

    particles.push(new Particle(x_, y_, s_, c_));

  }

}

​

function Particle(x_, y_, s_, c_) {

  this.x = x_;

  this.y = y_;

  this.size = s_;

  this.c = c_;

  this.dist = 0.5;

  this.move = function() {

    let theta = noise(this.x * squiggliness, this.y * squiggliness)*PI*4;

    let v = p5.Vector.fromAngle(theta, this.dist);

    this.x += v.x;

    this.y += v.y;

    //this.dist *= 0.9999;

    //this.alpha *= 0.99;

  }

  this.draw = function() {

    fill(this.c);

    circle(this.x, this.y, this.size);

  }

}