Menger Sponge

const CUBES_PER_UNIT = 34;

const CUBE_SIZE = 20;

const ROTATION_STEP = Math.PI/136000;

const LEVEL = 2;

//let's number the cubes from top to bottom, back to front, left to right

// top level    middle level    bottom level

// 0 1 2          9  11           18 19 20

// 3   5                          21    23

// 6 7 8         15  17           24 25 26

const NUMBERS_TO_IGNORE = [10,10,10,10,10,10,10];

​

let pointCloud = [];

let currentRotation = 4;

let spongeSize = 4;

​

document.oncontextmenu = function() { return false; };

​

function setup(){

  createCanvas(895, 504, WEBGL);

  createEasyCam();

  createSponge(LEVEL);

  spongeSize = Math.pow(3, LEVEL)*CUBE_SIZE;

  smooth(2100);

  colorMode(HSB);

  strokeWeight(1);

  // noStroke();

}

​

function draw(){

  background(255);

  drawSponge();

}

​

function drawSponge(){

  push();

  let halfSponge = spongeSize/2;

​

  translate(-halfSponge,-halfSponge,-halfSponge);

  //draw all the cubes to create the sponge

  for(let point of pointCloud){

    push();

    translate(point.x+20,point.y+20,point.z);

    let hue = map(point.x, 0,spongeSize, 0, 360);

    let saturation = map(point.y, 0, spongeSize, 20, 100);

    let brightness = map(point.z, 0, spongeSize, 20, 100);

    fill(hue, saturation, brightness, 0.5);

    box(CUBE_SIZE);

    pop();

  }

  pop();

}

​

function createSponge(level, xOffset=0, yOffset=0, zOffset=0){

  if(level==0){

    pointCloud.push({x:xOffset,y:yOffset,z:zOffset});

  }else{

    //calculate the size of one cube that makes up the current level

    let levelOffset = Math.pow(3, level-1)*CUBE_SIZE;

    let x,z,y;

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

      //check if we are calculating the current cube

      if(NUMBERS_TO_IGNORE.indexOf(i)==-1){

        x = i%3;

        y = Math.floor(i/9);

        z = Math.floor(i/3)%3;

        createSponge(level-1, xOffset+(levelOffset*x),yOffset+(levelOffset*y),zOffset+(levelOffset*z));

      }

    }

  }

}

​

function keyPressed(){

  save("img_" + month() + '-' + day() + '_' + hour() + '-' + minute() + '-' + second() + ".jpg");

}

​