Re: Problems with Transparent geometry
Rémi Arnaud (remi++at++remi.engr.sgi.com)
Thu, 22 Jan 1998 16:47:44 -0800 (PST)
Mario Veraart wrote:
>
> Hello,
>
> I have a problem with the rendering of transparent objects.
> It gives the impression that the BACK_TO_FRONT sorting does not work
> for the Transparent bin of a pfChannel. Or it could be that the
> geometry isn't put into the transparent bin and is sorted based on the
> geostate.
> The effect I see is that depending on the position of the viewer with
> respect of the transparent objects you sometimes doesn't see the
> objects that are behind the nearest object. I use BLENDING for
> transparency, because multisampling for a close objects look bad.
>
> I have made a very small program that shows what I mean.
> I have appended the code lines below that can be added to the demo
> program /usr/share/Performer/src/pguide/libpf/C++/complex.C .
> Run it without any arguments.
>
> Depending on the viewer you can't see the green and blue cube if the
> red one is the nearest. And you can see the red and the green one if
> the blue cube is the nearest. At least that is what I see.
>
> I force the bin to put the geometry in to the transparent one and
> according to the manual page the default sorting mode of this bin is
> BACK_TO_FRONT. Setting the required mode for the bin makes no
> difference.
>
> I use Performer 2.0 on a Max Impact.
>
> Any clues to what might solve this artefact would be great.
The sorting is turned off in complex.C. You will have to add
PFCULL_SORT to setTravMode (or use PFCULL_ALL) to enable
sorting in bins.
Regards
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on Mon Aug 10 1998 - 17:56:36 PDT