[vtkusers] visualizing NURBS++ surfaces (maybe a FAQ??)

[Giancarlo Facoetti]

Hi Bryn, thank you for your message.
NURBS++ has a function that provide the triangulated surface, but it's 
very slow, it recomputes the triangles mesh everytime I call it.

I have to investigate in a deeper way if NURBS++ provides direct access 
to the rendered triangles/quads (I fear that it uses the gluNurbsSurface 
functions, without create them explicitely)
thank you!
Giancarlo

> Hi Giancarlo
>
> It looks like the class vtkExplicitCell is abstract and there seems to 
> be no child classes VTK. I haven’t used it (subclassed), so cannot 
> help there.
>
> Maybe the NURBS++ library can also output triangles or quads (it 
> manages to generate them for OpenGL rendering, so they exist somewhere).
>
> Then you could fill a vtkPolyData with these triangles/polygons and 
> render as usual with VTK.
>
> Good luck
>
> Bryn
>
> *From:* vtkusers-bounces at vtk.org [mailto:vtkusers-bounces at vtk.org] *On 
> Behalf Of *Giancarlo Facoetti
> *Sent:* Tuesday, August 23, 2011 9:55 AM
> *To:* vtkusers at vtk.org
> *Subject:* [vtkusers] visualizing NURBS++ surfaces (maybe a FAQ??)
>
> Hi everybody,
>
> I'm using an open source library for NURBS management, called NURBS++.
> I'm able to do everything: creation of the surface, control points 
> moving, surface points moving, visualiation of the surface with OpenGL 
> (gluNurbsSurface...)
> I'm developing a VTK based application, and now I need to visualize 
> the NURBS++ surfaces into VTK pipeline, therefore without using 
> gluNurbsSurface but the VTK rendering
> I found in the VTK documentation the class vtkExplicitCell.h that 
> tells about NURBS surfaces, but I didn't understand how to use it. 
> (http://davis.lbl.gov/Manuals/VTK-4.5/classvtkExplicitCell.html)
> Do you have some suggestion please?
> thank you!
>
> Giancarlo
>