soft topographic surface
 

Hi! I am new with maya, and start to building a topographic surface. I have many contours (autocad polylines) and I want to "loft" them in a SOFT surface. Maya doesn't import very well these polylines if they have curves or arcs, so the contours are linear polylines.
How could I do to make a soft topographic surface?

I have no idea!!!!!!!!!!!

Thank you very much!!!!