Re: ghost polygons
Alejandro Saez (cano++at++silicon.cl)
Tue, 28 Apr 1998 11:01:38 -0400
On Apr 28, 11:30am, Liu Xiaoyan wrote:
> Subject: Re: ghost polygons
> > > For certain models displayed in our performer applcation, there are
> > > some ghost polygons flashing around. While viewed in IVVIEW or
> > > saved as .pfb files, they are gone. What's happening? The machine
> > > used is Onyx2 with 2 IR , performer 2.1.
> >
> > Depends on what you mean by "ghost polygons". Might be a problem with
> > your models where there are polygons with their back-faces enabled. >Can
you be a bit more specific to help us exorcise your ghosts ?
> >
>
> By 'ghost ploygons' I mean they don't exsit at all in our original
> geometry when built in Alias and other software. After exported to .iv
> and viewed in perfly, ivview , they don't come out. Only in our
> CAVE performer application do they appear.
>
> They are mostly in the form of triangles(with two-sided lighting
> on or off), appear randomly depend on my eye position. Our application
> is basically a 4 channel(2 channels share a pipe) program.
>
> Thanks.
>
> Liu
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>-- End of excerpt from Liu Xiaoyan
Could it be a Z buffer resolution problem??? Make sure you have enough Z bits
and that the far/near plane ratio doesn't exceed around 10000. Different
programs might have different default settings, thus triggering the effect.
--
------------------------------------------------------------------------
Alejandro Saez
Software Engineer
Silicon Chile S.A.
Avda. Andres Bello 2777, Of. 602
E-mail: asaez++at++silicon.cl Providencia
Phone: +56 (2) 203 3371 Ext. 105 Santiago
Fax: +56 (2) 203 3370 Chile
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on Mon Aug 10 1998 - 17:57:18 PDT