se if (code === 220) { // \
          _handleSingleKey('\\');
        } else if (code === -1) {
          // nothing
        } else {
          _handleDefaultKey(code, shiftKey);
        }
      };
      mesh.handleKey = _handleKey;

      mesh.plane = new THREE.Plane();
      mesh.leftLine = new THREE.Line3();
      mesh.topLine = new THREE.Line3();
      mesh.update = () => {
        mesh.leftLine.start
          .set(-menuWorldWidth/2, menuWorldHeight/2, 0)
          .applyMatrix4(mesh.matrixWorld);
    