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>