[vtkusers] Cannot see imagedata behind transparent polydata

Francois Bertel francois.bertel at kitware.com
Wed Mar 10 10:03:13 EST 2010 

There is no image3DActor in VTK. The only class with a similar name is
vtkImageActor. Are you talking about this one?

Does your OpenGL implementation has the required extensions?

ref: http://www.vtk.org/Wiki/VTK/Depth_Peeling#Required_OpenGL_extensions


Also, step 1 and 2 have to be called before the first render, they
cannot be changed after that:
1. renderWindow->SetAlphaBitPlanes(1);
2. renderWindow->SetMultiSamples(0);

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

The other steps can be called at any time and will be effective at the
next call the renderWindow->Render(), like:
renderer->SetUseDepthPeeling(1);
or
renderer->SetUseDepthPeeling(0);


On Wed, Mar 10, 2010 at 7:48 AM, Mathieu P <mtp.vtk at gmail.com> wrote:
> Bonjour François,
> I use image data into image3DActor.
> By rendering, i just add an image3DActor into the renderer.
> I have 2 images, and one polydata :
>
>       A           the camera
> --------------      first image (opacity = 20%)
> --------------      second image (opacity = 20%)
> OOOOOO      polydatas
> I can see the polydatas tough both transparent image, only if the polydatas
> opacity is set to 100% (not transparent).
> If i move my polydatas opacity to 99%, the polydata disappear behind both
> images.
> Second question :
> can i activate the depth peeling after the renderer constructor. I have
> tried to use renderer->Refresh(), and RendererWindow->Start(), but i cannot
> activate depth peeling after first renderer->Render();
>
> Thanks a lot,
>
> Cordialement,
>
> -- Mathieu PICCIN
>
>
>
>
> On Mon, Mar 8, 2010 at 2:36 PM, Francois Bertel
> <francois.bertel at kitware.com> wrote:
>>
>> Is your imagedate 2D? 3D? How do you display your imagedata (ie what's
>> your pipeline)?
>> If your imagedata is 3D and by "displaying imagedata" you mean volume
>> rendering, then no you cannot mixed translucent polygonal geometry and
>> volume rendering.
>>
>> On Mon, Mar 8, 2010 at 8:05 AM, Mathieu P <mtp.vtk at gmail.com> wrote:
>> > Hi,
>> >
>> > I have done some tests, and i can see image data behind transparent
>> > polydata, but i cannot see polydata behind transparent image data with
>> > depth
>> > peeling method !
>> >
>> > It's very strange because without depthpeeling, it's workling well both
>> > sides.
>> >
>> >
>> > Cordialement,
>> >
>> > -- Mathieu PICCIN
>> >
>> >
>> >
>> >
>> > On Thu, Mar 4, 2010 at 10:22 AM, Mathieu P <mtp.vtk at gmail.com> wrote:
>> >>
>> >> Martin,
>> >>
>> >> The solution of using depth peeling doesnt come from me, but from
>> >> Francois
>> >> Bertel, from KitWare.
>> >> I dont know how do make depth peeling working with transparent
>> >> polygons...
>> >>
>> >>
>> >>
>> >> Cordialement,
>> >>
>> >> -- Mathieu PICCIN
>> >>
>> >>
>> >>
>> >>
>> >> On Thu, Mar 4, 2010 at 9:31 AM, Martin Allerstorfer
>> >> <allerstorfer_martin at gmx.at> wrote:
>> >>>
>> >>> But the biggest problem I have at the moment is that I cannot see the
>> >>> imagedata behind transparent polygons? Sorry for writting so many
>> >>> questions
>> >>> but it is quite urgent for me.
>> >>>
>> >>> Thank you so much,
>> >>> Martin
>> >>>
>> >>> > 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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>> >>> > jetzt kostenlos herunterladen! http://portal.gmx.net/de/go/chbrowser
>> >>> > _______________________________________________
>> >>> > 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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>> >>> jetzt kostenlos herunterladen! http://portal.gmx.net/de/go/atbrowser
>> >>> _______________________________________________
>> >>> 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
>> >
>> >
>>
>>
>>
>> --
>> François Bertel, PhD  | Kitware Inc. Suite 204
>> 1 (518) 371 3971 x113 | 28 Corporate Drive
>>                      | Clifton Park NY 12065, USA
>> _______________________________________________
>> 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
>
>



-- 
François Bertel, PhD  | Kitware Inc. Suite 204
1 (518) 371 3971 x113 | 28 Corporate Drive
                      | Clifton Park NY 12065, USA

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