I have a NURBS surface and N control points. Now I want to evaluate a point P(u, v). I need the weight w and derivative wu, wuu, wv, wuv and wvv wrt to each control point. Has anyone got an idea of which function should I use? Thanks.
Note : openNURBS is an open source toolkit for only reading and writing 3DM files. Our full-featured development platform is provided in the Rhino SDKs.
The Rhino SDK is for writing Rhino and Grasshopper plug-ins, not standalone code.
You will need to find a different library or write your own functions based on the NURBS equations. The NURBS Book by Piegll and Tiller is a good reference.
My apologies, but it is not clear what you are asking for. Can you please describe the problem you are trying to solve, and why you are trying to solve it?