Hello everybody.  :o)

I see you're currently discussing radiosity, so please let me add my
thoughts. I'm aware that the attached pictures aren't beautiful, but
they are meant as a suitable test. Hope you can accept them.

I experimented with some ideas, cause I look forward to the day where
raytracing produce realistic looking pictures, and I'm trying to make
POV do it, do it first, and do it BEST! Of course.

Please understand the concept: I have skipped all "light_source"
commands because they are poor fakes. Instead I try to use a realistic
enviroment. This means, I set up any object and let it's ambient value
determine how much light it emits with radiosity. Then I (as with the
sphere in the attached pictures) use blurred reflection to get specular
highlights on light-absorbing objects.. This is the realistic way of
making highlights, instead of specular / blinn / phong keywords.

I managed to balance these 3 things well:

(1) The "brightness" value in radiosity global settings.
(2) The strength of ambient values (going much over 1) to emit light.
(3) The diffuse & reflection keywords on light-receiving objects.

But the problem: I experimented with the best radiosity-settings I could
think out, and find.. With recursion_limit set to 1, results look pretty
good; actually very similar to ordinary light_sources but with some
plusses: a WHOLE object emit light, specular reflections are realistic,
ans render times acceptable.

BUT the light doesn't bounce off, more than once. It goes from the light
sources (the ambient objects) to the first receiving object, and no
further. So a shadow will still be completely dark, if there is no
direct light source on the other side.

The solution is obvious: Raise recursion_limit to 2, but I got stuck
here, as things immediately look awful, no matter what I do.. Does
anyone have an idea WHY, and is there a solution??  I would be
interested.. Unfortunately, render times on the awful picture was very
high.. I tried to further raise radiosity quality to get rid of the
artifacts, and had to break a rendering after 12 hours, not finished,
and the result didn't look any better.

So help me! Help all of us, to get realistic lighting! And please don't
say radiosity is great, until these big problems are solved.


Hugo

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