box b1 10 6 10
polyline p 2 0 5  2 2 5  2 2.5 3  2 3 5  2 3 10 2 0 10  2 0 5
mkplane f p
prism b2 f 6 0 0
bcut s b1 b2
donly s

offsetparameter 1e-7 c i r
offsetload s 2.5
offsetperform result

checkprops result -s 1140 -v 2460

unifysamedom result_unif result
checknbshapes result_unif -face 10 -shell 1
