Firing from view center...
nirt: illegal option -- F
Usage: 'nirt [options] model.g objects...'
Options:
-b back out of geometry before first shot
-B n set rt_bot_minpieces=n
-e script run script before interacting
-f sfile run script sfile before interacting
-M read matrix, cmds on stdin
-O action handle overlap claims via action
-s run in short (non-verbose) mode
-u n set use_air=n (default 0)
-v run in verbose mode
-x v set librt(3) diagnostic flag=v
-X v set nirt diagnostic flag=v
mged>