Brian Furtaw (brian++at++sgi.com)
Tue, 21 Jan 1997 08:55:44 -0500
Brian
On Jan 21, 1:27pm, Angus Dorbie wrote:
> Subject: Re: Shadow and projected texture
> On Jan 20, 8:41pm, Brian Furtaw wrote:
> > Subject: Re: Shadow and projected texture
> > On Jan 20, 6:25pm, Angus Dorbie wrote:
> > > Subject: Re: Shadow and projected texture
> > > On Jan 8, 6:15am, pere1++at++cluny.ensam.fr wrote:
> > > > Subject: Shadow and projected texture
> > > > Like Scott McMillan and Mark Baranowski, I try to make shadows
with
> > > > Performer 2.1 and Irix 6.2.
> > > >
> > > > Remi ARNAUD says:
> > > > > OpenGL shadows are not supported by Performer 2.x, but the OpenGL
> shadow
> > > > > extensions are in the patch 1355 for 6.2.
> > > >
> > > > Is this the solution ? if, it is, ok I will install this patch.
> > >
> > > Well what Remi has just said means that 1355 is essential but even with
> > > it it's not a solution: "OpenGL shadows are not supported by Performer
2.x"
> > >
> > > Compile for IrisGL and perhaps this will support the shadows via IrisGL
> > > and IGLOO.
> > >
> > > Failing this you'll have to hand code the OpenGL shadows multi-pass.
> > >
> > > Cheers,
> > > Angus.
> > >
> > > =======================================================================
> > > List Archives, FAQ, FTP: http://www.sgi.com/Technology/Performer/
> > > Submissions: info-performer++at++sgi.com
> > > Admin. requests: info-performer-request++at++sgi.com
> > >-- End of excerpt from Angus Dorbie
> >
> >
>
> Brian,
> For the sake of avoiding confusion:
>
> Remi clearly stated that you need patch 1355 for shadows in OpenGL.
> If you have shadows in OpenGL you can support this yourself
> using performer but the support Remi is talking about is automatic
> shadows using performers multipass capability; PFTRAV_MULTIPASS and
> the pflightsource; PFLS_SHADOW_ENABLE. This works for an IrisGL
> compile in Performer but not OpenGL.
>
> I hope this is clearer now.
>
> Cheers,
> Angus.
>
> > Angus,
> > I think Remi was trying to say that performer does not have a node that
> > implements OpenGL shadows. Not that OpenGL shadow extension would not work.
> > Even with the OpenGL shadow extension you still have to do two passes one
> > to render to the depth buffer from the point view of the light source. Then
> > in the final pass you load the depth buffer information into the texture
> > memory using the OpenGL extension and render from the point of view of the
> > observer. You can read about this in glintro. SO you will need to draw the
> > channel twice with two different viewpoints. The OpenGL calls can be put
> > into a post-draw callback.
> >
> > Brian
> >
> > --
> > o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o
> >
> > Brian Furtaw (brian++at++sgi.com)
> > VisSim Technical Consultant
> > 12200-G Plum Orchard Drive Office: (301)572-3293 Fax:
(301)872-3293
> > Silver Spring, Maryland 20904
OpenGL/ImageVision/OpenInventor/Performer
> >-- End of excerpt from Brian Furtaw
>
>-- End of excerpt from Angus Dorbie
-- o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-oBrian Furtaw (brian++at++sgi.com) VisSim Technical Consultant 12200-G Plum Orchard Drive Office: (301)572-3293 Fax: (301)872-3293 Silver Spring, Maryland 20904 OpenGL/ImageVision/OpenInventor/Performer ======================================================================= List Archives, FAQ, FTP: http://www.sgi.com/Technology/Performer/ Submissions: info-performer++at++sgi.com Admin. requests: info-performer-request++at++sgi.com
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