[Radiance-general] Re: rendering parameters

[Roland Schregle]

Greg Ward wrote:
> 
> > From: Roland Schregle <ganjatron@gmx.net>
> >
> > Greg Ward wrote:
> >>
> >> Hi Ada,
> >>
> >> I should have been more specific -- setting -ab 0 -av 0 0 0 eliminates
> >> _diffuse_ interreflections in the calculation -- specular reflections
> >> will still be present.  The only way to get rid of specular
> >> reflections
> >> (reliably) is to eliminate specular components from your materials.
> >> In
> >> the case of a glass surface, you would have to substitute trans with a
> >> zero reflected component.
> >
> > Doesn't -lr 0 truncate *all* interreflection, specular and diffuse?
> >
> > --Roland
> >
> 
> Well...  It's never simple with Radiance, is it?  You would think that
> -lr truncates reflections, and usually it does, but you'll still get
> the direct component in there, which includes the specular highlight if
> the roughness value is non-zero.

Yeah, but that's not specular INTERreflection, which Ada was trying to
suppress. Or not? What was the original question? :^)

And just to make it a little more complicated: how does this affect
virtual sources?

--Confused

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