ref: 2c9c2ed710ed586b58d0f9958fdde32146733aec
dir: /examples/filter.orca/
......................................... .#.FILTER.#.............................. ......................................... ......................................... ......................................... ......................................... .......................3D................ ..............8D.H....................... ................xE......u................ .......................E.......E.......E. ......................................... ......................................... ......................................... ......................................... ......................................... ......................................... .........................................