Today I've tested SMath Studio graphs. Examples I've used I found here: twt.mpei.ac.ru/ochkov/Lace/Lace.htm I just improved the logic a bit and made common function for such surfaces scanning. Below you can find screenshot and the file I've worked with.
Yes, I've created that file using newer version but you still can open it by 0.90 (checked) - just press "yes" in the dialog on application start. Note that accuracy (the last argument of the scanSurface() function in the file is smaller then I've shown on screenshot).