[vtkusers] vtkCamera question

[Weiguang Guan]

Hello,

I want to generate stereographic projection of a semi-sphere. Can anyone 
point out what's wrong with the code below? It shows nothing on the screen.

         camera->ParallelProjectionOff();

         camera->SetFocalPoint(0.0, 0.0, 0.0);
         camera->SetPosition(0.0, 0.0, radius);
         camera->SetViewUp(0.0, 1.0, 0.0);

         camera->SetViewAngle(150.0);
         camera->SetClippingRange(radius, 2.0*radius);

Thank you very much.

Weiguang