Q: Does anyone know of a way to loft an open polygon, can you loft a straight line?

What I need to do is create an object that has the cross section of a straight line (a 3D surface mesh), I know that it is possible to load a 2D shape from the shaper into the 3D editor, but this object can not be contorted with the curves and bends that can only be produced by a loft path.

Any ideas?

A: This can be done directly in MAX.
There is, of course, a workaround in 3DS Classic... :o)

Create the open shape in the Shaper. Use the Close command to close it. Place the Hook on the line you need. Turn "Cap Start" and "Cap End" OFF and Loft as usual. In 3D Editor, select the faces you don't need and delete them. You have your open shape lofted along the path...

Addition:

For a straight line, the best way is to loft a rectangle and then delete the 3 sides you don't need.