ref: 5578e46dce7b516ea5288ebf4c7cdf9562203c47
dir: /examples/filter.orca/
......................................... .#.FILTER.#.............................. ......................................... ......................................... ......................................... ......................................... .......................3D................ ..............8D.H....................... ................xE......u................ .......................E.......E.......E. ......................................... ......................................... ......................................... ......................................... ......................................... ......................................... .........................................