[vtkusers] Cannot see imagedata behind transparent polydata

[Martin Allerstorfer]

I just found out that it works also with imagedata but only for certain distances.
If I zoom into the imagedata suddenly polydata is shown behind imagedata,
but it should be the other way round.
Is there an additional parameter to define the distance where depth peeling starts?

Thanks,
Martin
 
> Datum: Thu, 04 Mar 2010 08:45:38 +0100
> Von: "Martin Allerstorfer" <allerstorfer_martin at gmx.at>
> An: vtkusers at vtk.org
> Betreff: [vtkusers] Cannot see imagedata behind transparent polydata

> Thanks for all the answers! Mathieu, your suggestion using depth pealing
> works for polydata, but if I want to use imagedata in the same renderer
> depth calculation does not work between polydata and imagedata? A solution for
> this problem would be great!
> 
> Thanks,
> Martin
> 
> >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
> >>>>> _______________________________________________
> >>>>> Powered by www.kitware.com
> >>>>>
> >>>>> Visit other Kitware open-source projects at
> >>>>> http://www.kitware.com/opensource/opensource.html
> >>>>>
> >>>>> Please keep messages on-topic and check the VTK FAQ at:
> >>>>> http://www.vtk.org/Wiki/VTK_FAQ
> >>>>>
> >>>>> Follow this link to subscribe/unsubscribe:
> >>>>> http://www.vtk.org/mailman/listinfo/vtkusers
> >>>>
> >>>
> >>
> >>
> >> _______________________________________________
> >> Powered by www.kitware.com
> >>
> >> Visit other Kitware open-source projects at
> >> http://www.kitware.com/opensource/opensource.html
> >>
> >> Please keep messages on-topic and check the VTK FAQ at:
> >> http://www.vtk.org/Wiki/VTK_FAQ
> >>
> >> Follow this link to subscribe/unsubscribe:
> >> http://www.vtk.org/mailman/listinfo/vtkusers
> >>
> >>
> 
> 
> -- 
> GRATIS für alle GMX-Mitglieder: Die maxdome Movie-FLAT!
> Jetzt freischalten unter http://portal.gmx.net/de/go/maxdome01
> _______________________________________________
> Powered by www.kitware.com
> 
> Visit other Kitware open-source projects at
> http://www.kitware.com/opensource/opensource.html
> 
> Please keep messages on-topic and check the VTK FAQ at:
> http://www.vtk.org/Wiki/VTK_FAQ
> 
> Follow this link to subscribe/unsubscribe:
> http://www.vtk.org/mailman/listinfo/vtkusers

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