Hi Eric, I also prefer to keep the unknown space, but it looks like much more hacky things have to be done. At the moment, we just want to test the Incremental heuristic search algorithms, and we are using the gmapping to do the slam in Stage. Cheers, Simon ----- 程晔 Simon -- View this message in context: http://ros-users.122217.n3.nabble.com/navfn-allow-unknown-tp1991577p2026254.html Sent from the ROS-Users mailing list archive at Nabble.com.