UBE_MAP);
  gl.texParameteri(gl.TEXTURE_CUBE_MAP, gl.TEXTURE_MIN_FILTER, gl.LINEAR_MIPMAP_LINEAR);

  function degToRad(d) {
    return d * Math.PI / 180;
  }

  var fieldOfViewRadians = degToRad(60);
  var modelXRotationRadians = degToRad(0);
  var modelYRotationRadians = degToRad(0);

  // Get the starting time.
  var then = 0;

  requestAnimationFrame(drawScene);

  // Draw the scene.
  function drawScene(time) {
    // convert to seconds
    time *= 0.001;
    // Subtract the previous time from the curr