puts "========"
puts "0026558: Failing to build isoline for offset surface"
puts "========"
puts ""

restore [locate_data_file bug26558_s.brep] s

mksurface sur s
offset o sur -0.5
uiso icur o 0

smallview
fit   
checkview -screenshot -2d -path ${imagedir}/${test_image}-3d.png