code: function (evt) {
      var shortcutPressed = evt.keyCode === 83 && evt.ctrlKey && evt.altKey;
      if (!this.data || !shortcutPressed) { return; }
      var projection = evt.shiftKey ? 'equirectangular' : 'perspective';
      this.capture(projection);
    }
docs: <ctrl> + <alt> + s = Regular screenshot.
  <ctrl> + <alt> + <shift> + s = Equirectangular screenshot.