box b1 0 0 0 1 1 1
nurbsconvert b1 b1
box b2  0    -0.5   0     0.5   1.5   1

bcommon result b1 b2

checkprops result -s 4
checkview -display result -2d -s -otherwise { b1 b2 } -path ${imagedir}/${test_image}.png