Cross Fractal

///////////////////////////////////
// CROSS FRACTAL //////////////////
/* recursive */

function cross(posI, posJ, posK, boxSize, iteration, maxIterations) {
  /* construction of menger sponge */
  for (var i = 1; i <= 3; i++) {
    for (var j = 1; j <= 3; j++) {
      for (var k = 1; k <= 3; k++) {
        if ( ( i == 2 && j == 1 && k == 2 ) ||
             ( i == 1 && j == 2 && k == 2 ) ||
             ( i == 2 && j == 2 && k == 2 ) ||
             ( i == 3 && j == 2 && k == 2 ) ||
             ( i == 2 && j == 2 && k == 1 ) ||
             ( i == 2 && j == 2 && k == 3 ) ||
             ( i == 2 && j == 3 && k == 2 ) ) {
          if (iteration < maxIterations) {
            cross((posI + i * boxSize), (posJ + j * boxSize), (posK + k * boxSize),
                     (boxSize / 3), (iteration + 1), maxIterations);
          } else if (iteration = maxIterations) {
            drawCube(i, j, k, posI, posJ, posK, boxSize, iteration, maxIterations);
          }
        }
      }
    }
  }
}
function drawCube(i, j, k, posI, posJ, posK, boxSize) {
  /* construct object */
  var object = new THREE.Object3D();
  /* cube */
  var mGeometry = new THREE.BoxGeometry( boxSize, boxSize, boxSize );
  var mMaterial = new THREE.MeshLambertMaterial( { color: 0xffff00 } );
  var cube = new THREE.Mesh( mGeometry, mMaterial );
  cube.position.set(posI + ((i + 1) * boxSize) - 3, posJ + ((j + 1) * boxSize) - 1,
    posK + ((k + 1) * boxSize));
  /* casting shadows */
  cube.castShadow = true;
  object.add ( cube )
  scene.add ( object );
}