[vtkusers] curved surfaces.

[David C Thompson]

> Can anybody please tell me how can I create a curved surface using
> vtk?
> So far I have tried with:
> 
>         vtkQuad
>         vtkQuadraticEdge
>         vtkQuadraticHexahedron
>         vtkQuadraticPyramid
>         vtkQuadraticQuad
>         vtkQuadraticTetra
> 
> and I can not get a rounded vertice.

I can see two problems you might be having:

1. VTK uses a coarse approximation to curved surfaces to make rendering
lots of elements fast. You can refine these approximations with
vtkTessellatorFilter ("Tessellate" in ParaView).

2. By default, VTK uses per-face (rather than per-vertex) normals. You
may use vtkPolyDataNormals ("Normals Generation" in ParaView).

	David