puts "============"
puts "0031688: Visualization - Wrong ISO lines for a face created from BSpline"
puts "============"
puts ""

pload MODELING VISUALIZATION
pbsplinecurve aa 2 4 0 1 1 1 2 1 3 1  0 0 0 1  1 2 0 1  2 0 0 1
mkedge ee aa
wire ww ee
mkplane ff ww
vinit
vdisplay ff
visos ff 50 50 1
vfit

if { [vreadpixel 365 200 -rgb -name] != "BLACK" ||
     [vreadpixel 366 200 -rgb -name] != "BLACK" ||
     [vreadpixel 367 200 -rgb -name] != "BLACK" } {
  puts "Error: isolines are not expected here"
}

vdump ${imagedir}/${casename}.png