code: function(min, max) {
      return function limitVfov(params) {
        params.fov = clamp(params.fov, min, max);
        return params;
      };
    }
docs: Returns a view limiter that constrains the vertical field of view.
  @param {number} min The minimum vertical field of view.
  @param {number} max The maximum vertical field of view.
  @return {RectilinearViewLimiter}