Geometry data representation

What is the underlying form used for storing geometric data?

Is is Bezier, rational Bezier, NURBS, a combination or something else?

I know the conversion to NURBS is fairly trivial. Can you work completely in NURBS? Or do you have to convert to bezier (in the case of NURB geometry coming from an external source).

I'm just starting out, so any discussion on how the underlying mathematics is implemented in CASCADE would be interesting to me.

Philippe Centa's picture

NURBS and Bezier curves and surfaces are supported, as well as conics or procedural geometry.

Through the adaptors (see Adaptor3d, Adaptor2d) theory that roughly stands on the fact that most of the algorithms are based upon the ability to get first and second derivatives from any u or (u,v), you can implement your proper curves and surfaces definition. Moreover there is no restriction for using any topological data-structure of operator on top of such geometry.