def setup 
  createCanvas(100, 100, WEBGL)
  normalMaterial
  @cam = createCamera
  @cam.tilt(-0.8)  # set initial tilt angle
  @delta = 0.01
end

def draw 
  background(200)

  # pan camera according to angle 'delta'
  @cam.tilt(@delta)

  # every 160 frames, switch direction
  if frameCount % 160 == 0
    @delta *= -1
  end

  rotateY(frameCount * 0.01)
  translate(0, -100, 0)
  box(20)
  6.times do
    translate(0, 35, 0)
    box(20)
  end
end