let cols; let rows; let size = 10;

let xoff = 0; let yoff = 0; let zoff = 0; let inc = 0.07;

​

function setup() {

  createCanvas(400, 400);

  cols = width/size;

  rows = height/size;

  rectMode(CENTER);

}

​

function draw() {

  background(255);

  yoff = 0;

  for (let i=0; i<rows; i++){

    xoff = 0;

    sizes[i] = [];

    for (let j=0; j<cols; j++){

      let s = map(noise(xoff, yoff, zoff), 0, 1, 0, size*1.2);

      sizes[i][j] = s; 

      xoff+=inc;

      // if no increment, then grayscale

      let r = 255 * noise(zoff);

      let g = 255 * noise(zoff+15);

      let b = 255 * noise(zoff+30);

      noStroke();

      fill(r, g, b);

      rect(size/2 + i*size, size/2 + j*size, sizes[i][j], sizes[i][j]);

    }

    yoff+=inc;

    zoff+=0.0003;

  }

​

}