[vtkusers] Cannot see imagedata behind transparent polydata

[Francois Bertel]

Dealing with non opaque geometry requires sorting the polygon to be
rendered. It would be extremely slow if it was
activated by default.

Try to use depth peeling. Follow these steps:

http://www.vtk.org/Wiki/VTK/Depth_Peeling#VTK_calls

You need OpenGL>=2.0 for it to work.

On Wed, Mar 3, 2010 at 12:35 PM, Mathieu P <mtp.vtk at gmail.com> wrote:
> I have attached a small image illustrating my problem.
>
> I cannot believe VTK cannot manage object opacity !
>
> Thanks for help.
>
>
> Cordialement,
>
> -- Mathieu PICCIN
>
>
>
>
> On Wed, Mar 3, 2010 at 4:50 PM, Mathieu P <mtp.vtk at gmail.com> wrote:
>>
>> Actually i am using vtkImageActor and i change their opacity with
>> setOpacity...
>>
>>
>> Cordialement,
>>
>> -- Mathieu PICCIN
>>
>>
>>
>>
>> On Wed, Mar 3, 2010 at 3:57 PM, Mathieu P <mtp.vtk at gmail.com> wrote:
>>>
>>> Same kind of problem here :
>>>
>>> I have two imageData :
>>>
>>> Image data A loaded first
>>> Image data B loaded after
>>>
>>> i modify the opacity to 50% for both image data.
>>> i can see tough the image data B, so the last loaded, but i cannot see
>>> toughthe image data A, the first loaded.
>>> Modifying the opacity of the forst loaded change only its luminosity (or
>>> alpha).
>>>
>>>
>>> Cordialement,
>>>
>>> -- Mathieu PICCIN
>>>
>>>
>>>
>>>
>>> On Wed, Mar 3, 2010 at 3:03 PM, Martin Allerstorfer
>>> <allerstorfer_martin at gmx.at> wrote:
>>>>
>>>> Hi,
>>>>
>>>> In my rendering view I would like to show imagedata and additionally
>>>> some information using transparent glyphs. But not all glyphs have the same
>>>> transparency. So I change the color and alpha settings for each cell of the
>>>> glyphs seperately. Unfortunately now I cannot see the volume behind the
>>>> transparent polydata. Does anybody know how to solve this problem?
>>>>
>>>> Thanks,
>>>> Martin
>>>> --
>>>> GRATIS für alle GMX-Mitglieder: Die maxdome Movie-FLAT!
>>>> Jetzt freischalten unter http://portal.gmx.net/de/go/maxdome01
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>>
>
>
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-- 
François Bertel, PhD  | Kitware Inc. Suite 204
1 (518) 371 3971 x113 | 28 Corporate Drive
                      | Clifton Park NY 12065, USA