There are basicly three types of modelers out there that each 3d CAD program can fit within. Some are hybrid like Maya.
2. Nurbs - Non Uniform Rational B-Spines
CATIA does the numbertwo of this family of product design software. Solidworks and Pro/E, Alias Studio all fall under number two as well. So to answer your question freeform would be a nurbs surface as well. Years ago when Catia became a parametric modeler we would say: Catia is a specific type of nurbs modeler.... one that is solids and parametric. Same for Pro/E and Solidworks. Where Alias studio is just a nurbs modeler. Maya on the other hand contains all of the above types of modlers into it's engine and a user can convert between each.
Maybe to reword the question because free form surfaces will still be nurbs in Catia. Edited by: design-engine
But the question still remains there only. If there are two surfaces in CATIA, then which oneis nurbs & not a nurbs.
1.Nurbs-defined by a parametric equation. & other
2.Asurface which is not defined by a parametric equation.
i don't have acess to model tree & operations.The second surface could possibly a imported surface from a different software, could be that it may have beencreated in some software like 3DSMAX, or some Non-Parametric software.then how do i find Nurbs from the two available software.