First of all, thanks for all the replies, there's more material here than in
the help.  I know - I really did look.  In fact, if you'll all turn to
section 4.1.3 of the help and scroll to the bottom, you'll see these exact
radiosity settings.

If you look at my last grass_test image - I used a far away point light and
didn't like the effect.  It seemed "sunny" on the objects, on a cloudy day.
That's why I even tried rad lighting.

question: will lowering count make the lighting down between the grass and
the Earth funky?

Also, I have added a radiosity "light" inside the spaceship
(blimp/whatever), does this change things?

I want the overall ambient-lit feeling that the point-light destroys, so I
am currently thinking of not using a point light unless absolutely
necessary.
Well, I could have a giant 100x100 jittered area light, but I'd like to
still be alive when it's done rendering.


"Xplo Eristotle" <xpl### [at] infomagicnet> wrote in message
news:406b28d9@news.povray.org...
> Bryan Valencia wrote:
>
> > I'm trying an outside scene on a cloudy day... it's the grass scene I
have
> > been posting.
> >
> > But the sky_sphere is always beautifully lit, while the rest of the
scene is
> > essentially black.
> >
> > Here are my settings, what's wrong?
> > global_settings {
> >  assumed_gamma .8
> >  ambient_light rgb .3
> >
> >     radiosity {
> >       pretrace_start 0.08
> >       pretrace_end   0.01
> >       count 500
> >
> >       nearest_count 10
> >       error_bound 0.02
> >       recursion_limit 1
> >
> >       low_error_factor 0.2
> >       gray_threshold 0.0
> >       minimum_reuse 0.015
> >       brightness 1
> >
> >       adc_bailout 0.01/2
> >     }
>
> I'm going to go ahead and partly disagree with everyone here... ;D
>
> First, the ambient_light global setting doesn't set a default ambient
> finish (that's what #default is for); it sets an ambient multiplier. So
> if you're using ambient finishes ANYWHERE in your scene, they will be
> multiplied by .3. If this is affecting your sky_sphere, that would be
> the cause of your problem.
>
> Second, your count is way too high for an outdoor scene with a large
> open sky; you're wasting a lot of cycles on quality that you probably
> can't see. Try using 100 or less (30 would be plenty for test renders)
> and don't increase it unless artifacting is a problem with the settings
> you're using for the final render.
>
> Likewise, your error_bound is way too low for most outdoor scenes;
> pretty much anything below .3 or so is only useful if you want really
> detailed radiosity shadows. Try a setting of .5 or so.
>
> Your low_error_factor can probably be set to 1, especially if you decide
> to use a smaller error_bound. (Go look it up.)
>
> Some people on these groups will recommend a ridiculously high
> recursion_limit. Don't listen to them, they're fools. Most outdoor
> scenes with wide open skies can get by with a recursion_limit of 1;
> indoor scenes will usually be fine with a recursion_limit of 2. The
> difference between 2 and 3 in most scenes is nearly invisible, and
> higher settings are useless for anything except *very* indirect
> lighting.. and even then, you'd probably want 16-bit output and
> post-processing to make any use of the data.
>
> -Xplo

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