Creating Solids and Surfaces from 2D - Autodesk AutoCAD 2013 Practical 3D Drafting and Design - page 113

ror once and rotate with copy to obtain all four splines. Adjust all vertices
with the adequate UCS.
Note
We have to apply splines as guides. The 2D polylines can only be ap-
plied if composed by only one segment. The easiest method to adjust
vertices is to turn off the Osnap function and apply the SPLINEDIT
command and select the Edit vertex option.
11. Finally, activate the BATHTUB layer and apply the LOFT command; first
select the four cross sections in the same order, press the Enter key, and
choose the Guides option, and then select each of the four splines. As
we select each spline, the lofted object adjusts accordingly. Then press
the Enter key to exit the command.