  An intuitive design method is proposed for generating developable ruled
B-spline surfaces from a sequence of straight line segments indicating the
surface shape. The first and last line segments are enforced to be the head and
tail ruling lines of the resulting surface while the interior lines are
required to approximate rulings on the resulting surface as much as possible.
This manner of developable surface design is conceptually similar to the
popular way of the freeform curve and surface design in the CAD community,
observing that a developable ruled surface is a single parameter family of
straight lines. This new design mode of the developable surface also provides
more flexibility than the widely employed way of developable surface design
from two boundary curves of the surface. The problem is treated by numerical
optimization methods with which a particular level of distance error is
allowed. We thus provide an effective tool for creating surfaces with a high
degree of developability when the input control rulings do not lie in exact
developable surfaces. We consider this ability as the superiority over
analytical methods in that it can deal with arbitrary design inputs and find
practically useful results.
