It is well known that Cayley’s ruled cubic surface carries a three-parameter family of twisted cubics sharing a common point, with the same tangent and the same osculating plane. We report on various results and open problems with respect to contact of higher order and dual contact of higher order for these curves.

In a recent works Liu and Wang 2008; 2007 study the Mannheim partner curves in the three dimensional space. In this paper, we extend the theory of the Mannheim curves to ruled surfaces and define two ruled surfaces which are offset in the sense of Mannheim. It is shown that, every developable ruled surface have a Mannheim offset if and only if an equation should be satisfied between the geodesi...

The geometry of ruled surfaces is highly relevant for freeform architectural design, owing to the fact that any negatively curved freeform shape can be approximated by a smooth union of ruled surface strips. This information is important for the efficient manufacturing of both skins and underconstructions. The present paper discusses how to algorithmically solve this approximation problem. In p...

The mu-basis of a planar rational curve is a polynomial ideal basis comprised of two polynomials that greatly facilitates computing the implicit equation of the curve. This paper defines a mu-basis for a rational ruled surface, and presents a simple algorithm for computing the mu-basis. The mu-basis consists of two polynomials p(x, y, z, s) and q(x, y, z, s) that are linear in x, y, z and degre...