Was surprised when I just created a ruled surface between 2 contour lines. There are very significant variations between the edges of the created surface (blue in the image below) and the contours (white) ... I would have expected the surface to follow the contours much more closely (the only places they seem to coincide are at the contour nodes).
David Henderson
dhSoftware - Add-on Macros for DataCAD
dhSoftware - Add-on Macros for DataCAD