From: MLM Veraart (veraart++at++fel.tno.nl)
Date: 03/04/2002 07:25:57
Hello,
An other cause could be the self-shadowing.
A piece of the pfLightSource man page
For best results, SHADOW lighting requires that the scene be slightly
displaced in depth when rendering the shadow map. This reduces artifacts
such as "self-shadowing". The PFLS_SHADOW_DISPLACE_SCALE and
PFLS_SHADOW_DISPLACE_OFFSET tokens to pfLightSource::setVal specify
displacement values. The default values are respectively: for IrisGL 1.0
and 256.0 for OpenGL 1.0 and .0019 but experimentation is required for
best results (both values should be positive).
Mario
Marcin Romaszewicz wrote:
>
> This is probably a numerical precision artifact. If you are using less
> than a 23-bit Z buffer, make it 23 bit and see if that helps.
>
> -- Marcin
>
> On Tue, 26 Feb 2002 yofer++at++newmail.net wrote:
>
> > Hello all,
> > When operating shadow casting pfLightsource on IR machines,
> >
> > I encountered polygonal shadow flickering .
> > The scene included a shadow caster and a terrains,
> > on which the shadow was casted. The terrain was either
> > fine grid polymesh or delauney, with or without textures.
> > In either case, when the terrain, on which the shadow
> > was casted, had significant height transitions, shadow
> > flickering appeared in vicinity to the "expected" shadow,
> > which was properly and continuously rendered .
> > How can this phenomena be eliminated ?
> >
> > Thanks,
> > Ofer.
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