var sizeB = 0;

​

function setup() {

  createCanvas(400, 400, WEBGL);

}

​

function draw() {

  background(255);

  strokeWeight(3);

  noFill();

  rotateY(mouseY/100);

  rotateX(mouseX/100); 

  stroke(230, 115, 157);

  sphere(250 + sizeS);

  sphere(100 + sizeS);

  sphere(25 + sizeS);

  stroke(90, 158, 95);

  box(200 + sizeB);

  box(90 + sizeB);

  if(keyIsDown(UP_ARROW)){

    sizeS = sizeS + 0.5;

    sizeB = sizeB + 0.7;

  }

  if(keyIsDown(DOWN_ARROW)){

    sizeS = sizeS - 0.5;

    sizeB = sizeB - 0.7;

  }

}

​