ref: d5aa4673d49bc348f53bc0ed9088601d041a8eb6
dir: /examples/filter.orca/
......................................... .#.FILTER.#.............................. ......................................... ......................................... ......................................... ......................................... .......................3D................ ..............8D.H....................... ................xE......u................ .......................E.......E.......E. ......................................... ......................................... ......................................... ......................................... ......................................... ......................................... .........................................