[vtkusers] Opacity not correct when using vtkColorTransferFunction

[Chiang, Wen-Hsing]

Hi,
refer to my previous message (see attached below) concerning the opacity
problem. I have tried the same code under two variants below, both
variants display the opacity correctly, So I would guess there is a bug
in vtk4.0. 

1.Use vtkColorTransferFunction and use vtk3.2 instead of vtk4.0.
2.Let the mapper to generate the lookup table instead of using my own
vtkColorTransferFunction.

Although my code works fine in vtk3.2. I'd like keep current with vtk4.0
if I can only solve this problem. Is there any solution?

Wen-Hsing Chiang



>Hi there,
>
>When I use vtkColorTransferFunction to map the color to an isosurface
>with opacity=0.2 for the actor, the isosurface seems to be opaque (it =
>is
>a little transparent though, something like opacity>0.9...). This
>problem does not exist when I use vtkLookupTable instead of
>vtkColorTransferFunction. However, the later is preferred as it gives
me
>more control.
>
>Is anyone aware of this problem? Any responses are appreciated. I am
>using vtk4.0.
>
>Wen-Hsing Chiang