ref: c593c3b2d5009c798486cdd3745ff0e160aeeeb6
dir: /examples/filter.orca/
......................................... .#.FILTER.#.............................. ......................................... ......................................... ......................................... ......................................... .......................3D................ ..............8D.H....................... ................xE......u................ .......................E.......E.......E. ......................................... ......................................... ......................................... ......................................... ......................................... ......................................... .........................................