Canyon (fork)

let particles=[];

let amount=800; // will be calculated in setup()

let noiseScale=0.005;

​

function setup() {

  createCanvas(windowWidth, windowHeight);

  amount = ~~((width + height) / 2);

  background("tan");

  noStroke();

  fill(32, 32);

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

    let pos =createVector(random(width),random(height));

    particles.push(pos);

  }

}

​

function draw() {

  for (let k = 0; k < 5; k++) {

    for(let i = particles.length-1; i>=0 ; i--){

      let p = particles[i];

      circle(p.x, p.y, 1);

      let n = noise(p.x*noiseScale, p.y*noiseScale, frameCount/noiseScale);

      let a = 2*PI*n;

      p.x += sin(a*random(1,1.2));

      p.y += cos(a)*map(sin(a/10), -1,1, -0.5,0.5);

      //p.y+=cos(a)*0.2

      if (!onScreen(p)) {

        // particles.splice(i, 1)

        p.x = random(width);

        p.y = random(height);

      }

    } // process particles

  } // repeat n-times

}

​

function onScreen(p) {

  return p.x < width && p.y < height && p.x > 0 && p.y > 0

}