I've never encountered what you mention is wrong, and it sounds
peculiar. Did you use more than 'adaptive 1'?  I'm sure you must be
using 'jitter' in that too, aren't you? But what it almost sounds like
is a 'area_light' whose plane is aligned with the small object
somehow.

Bob

John M. Dlugosz <joh### [at] dlugoszcom> wrote in message
news:37cc8e2e@news.povray.org...
> I'm rendering a artist's studio that has sunlight coming in from the
glass
> roof.  Leaving that as the only light source and cranking up the
ambiant on
> the contents of the room doesn't look real at all.
>
> Putting a fill light off to one side makes shapes look better (not
"flat")
> but adds shadows that are wrong.
>
> Putting a large area light to one side looks great, for the major
elements
> of the scene.  Objects don't cast distinct shadows from this light
source
> but do show the vague darkening on the floor and close walls that we
see in
> a real room full of ambient light.  The =illumination= is still a
point, not
> a large surface, but it looks fine in this case.
>
> However, I'm still getting stray shadows.  I got a sharp shadow from
a small
> object onto a nearby flat surface, which I presumed was because the
> "adaptive" fails when the object is smaller than the light.  Hmm, on
second
> thought that's not right at all, as this would make =no= shadow (all
four
> corners of the light are unblocked when the object is in the
middle), not a
> sharp shadow with no prenumbra.
>
> I tried turning off adaptive, and I still get a sharp shadow, even
though
> there are 25 sublights.  I'm trying a much larger number of
sublights now,
> but it's taking a long time to render.  If that shows no change, I
don't
> understand what's happening.
>
> Anyway, I found that the "darkening" effect does a great deal toward
making
> a room look real.  If this isn't the best way to acheive that in an
ambient
> light situation, what is?  Would radiosity be the answer here, or
does it
> not help with this effect?
>
> --John
>
>
>

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