message: Add a very useful comment suggested by Marco.
diff: @@ -584,5 +584,18 @@ private:
  bool _beforeMoviePreloadSiblings;
  int32_t _beforeMovieLoadingDescendantLimit;
  bool _beforeMovieKeepWorldOriginNearCamera;
  +
  + // This is used as a workaround for cesium-native#186
  + //
  + // The tiles that are no longer supposed to be rendered in the current
  + // frame, according to ViewUpdateResult::tilesToNoLongerRenderThisFrame,
  + // are kept in this list, and hidden in the NEXT frame, because some
  + // internal occlusion culling information from Unreal might prevent
  + // the tiles that are supposed to be rendered instead from appearing
  + // immediately.
  + //
  + // If we find a way to clear the wrong occlusion information in the
  + // Unreal Engine, then this field may be removed, and the
  + // tilesToNoLongerRenderThisFrame may be hidden immediately.
  std::vector<Cesium3DTiles::Tile*> _tilesToNoLongerRenderNextFrame;
  };
  