[vtkusers] Shading Problems with Para.Surf.

[David Doria]

On Fri, Oct 22, 2010 at 7:52 AM, Elias Breunig <elias.breunig at googlemail.com
> wrote:

> Dear all,
>
> I've written a Parametric Paraboloid class that generates paraboloid
> surface data. It is based on vtkParametricEllipsoid and I basically
> just exchanged the fundamental equations and definitions. Works fine
> so far, but when I render the surface i get a somehow strange shading
> effect on the surface, to be more prescise, a quard-foil of dark areas
> (see attached image). Has anyone an idea where this might originate
> from and how to get rid of it. I played around a bit with ambient and
> diffuse parameters but couldn't achieve any effect at all.
>
> Thanks for advice
>
> Elias
>

My guess is that your normals are incorrect. Try:
actor->GetProperty()->SetInterpolationToFlat();

to turn off shading which uses the normals and see if looks correct.

David
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