0;
  }

  // First let's make some variables
  // to hold the translation,
  var fieldOfViewRadians = degToRad(60);
  var modelXRotationRadians = degToRad(0);
  var modelYRotationRadians = degToRad(0);

  var then = 0;

  requestAnimationFrame(drawScene);

  // Draw the scene.
  function drawScene(now) {
    // Convert to seconds
    now *= 0.001;
    // Subtract the previous time from the current time
    var deltaTime = now - then;
    // Remember the current time for the next frame.
    then = now;

    