Lofting has its heritage from shipbuilders as they laid out ship hulls. They passed imaginary lines between multiple sequential cross-sections. A lofted surface creates a smooth surface from cross-sectional curve data. The curves can be non-planar as well.
Follow these steps to create a lofted surface:
The curves for the lofted surface must already exist in position in the drawing before you can create a lofted surface.
Use the Surface wizard or select Lofting from the surface toolbar flyout.
Name the surface for future reference.
Pick the curves with the mouse and pick button, or choose them in the list and click Plus.
If you pick them out of sequence, change the sequence with the Up and Down arrow buttons.
Specify an acceptable Tolerance. Tolerance means that the resulting surface may deviate from the exact offset by no more than value you enter.
Click Preview to view the surface.
Set either the Interpolated or Spline radio button. Use Preview to see the difference.
Set the Uneven spacing switchbox as needed for the best surface match. Use Preview to see the difference.
It is quite possible that your surface will flip between adjacent curves. Use Curve reverse to reverse the curve. If you have multiple flips, do each curve separately as it is easy to get confused about how the surface might flip after you have reversed many curves.
Decide whether to set Reparameterize curves.
Click Preview to see how the current settings affect the surface. Make adjustments as necessary until the surface is how you want it.
Click Finish or OK to create the surface.
An example of a lofted surface.