[vtkusers] Dark actors with Mesa

[Jérôme Coloos]

Hello,

I posted a message last week for a problem of dark actors on Linux
http://public.kitware.com/pipermail/vtkusers/2001-February/005548.html

I still doesn't found any solution but my problem seems to be more general
than I sayed.


I'm using VTK libs on several plateforms and I found that the problem
occured on IRIX and Linux when I used Mesa (3.4) instead of the default
OpenGL.

Actors became very dark   when they are scaled down,
              very bright when they are scaled up.

My example was :

  vtkConeSource *cone = vtkConeSource::New();
    cone->SetRadius(1);
    cone->SetHeight(0.00001);
  vtkDataSetMapper *mapper = vtkDataSetMapper::New();
    mapper->SetInput(cone->GetOutput());

  vtkActor *actor = vtkActor::New();
    actor->SetMapper(mapper);
    actor->SetScale(10000,1,1);     /////    VERY DARK ACTOR

    cone->SetHeight(10000);
    actor->SetScale(0.00001,1,1);   /////    VERY BRIGHT ACTOR

Does anybody experienced the same problems ?
Is there a solution to manually change the light so that it looks normal ?

__________________________________________
   ___    Jérôme COLOOS
 @/   \@  Tel : 32-4/361.69.69
  \° °/   Fax : 32-4/361.69.80
 ==\ /==  mailto:jerome.coloos at samcef.com
    °     http://www.samcef.com
SAMTECH s.a.
Parc Scientifique du Sart-Tilman
rue des Chasseurs-Ardennais, 8
B-4031 Angleur-LIEGE
___________________________________________