A ruled surface parameterization is called noncylindrical if
is nowhere
. A noncylindrical ruled surface always has a parameterization
of the form
where
and
,
where
is called the striction curve of
and
the director curve.
A ruled surface parameterization is called noncylindrical if
is nowhere
. A noncylindrical ruled surface always has a parameterization
of the form
where
and
,
where
is called the striction curve of
and
the director curve.
Weisstein, Eric W. "Noncylindrical Ruled Surface." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/NoncylindricalRuledSurface.html