The problem seems to be that radiosity, like media, is distance-sensistive (i.e.
it performs differently at different scales). Apparently, the best distances
(meaning the size of the room for instance) are the ones used in the radiosity
example, so I use them as a basis. What I do is to give a general scale to the
whole scene (including the lights and the camera) and use this general scaling
factor to tune the picture for the best quality vs render time. I ran in exactly
the same problems as the ones you mention (plus the fact that a very low
error_bound seemed to crash the picture due to a lack of memory) and these
problems disappeared using the standard radiosity settings (in rad.inc)  with
the "right" distances. And the good news was that radiosity was not that slow. I
also noted that some radiosity artifacts are nicely smoothed by antialiasing.
I hope this helps.
Gilles

Nieminen Mika wrote:

>   I'm trying to find proper radiosity settings for an indoors scene.
> However, no matter what I do, I get one of the following:
>   1. Very blotchy illumination, like someone was throwing paint on the
> walls at random.
>   2. Quite smooth illumination but somewhat grainy and extremely annoying
> small dark spots in corners.
>
>   I get the second type of illumination with settings which take centuries
> to calculate (in my P-II 350MHz). If I use a little bit faster settings
> I get the first type of illumination.
>   Those dark spots in the second case appear no matter how small
> error_bound I specify (I have gone as small as error_bound 0.05).
>   The distance_maximum seems to be the key value which controls how much
> the image goes to the first or the second case. With large distance_maximum
> values the image gets blotchy while with small values it gets grainy.
> I have tried several values between 1000 (the room is about 200 units wide)
> and 1. With very small values the render time blows up and the walls look
> like they had a finish { crand .2 }.
>   The rendering time doesn't matter, but I just can't get rid of the
> graininess and the annoying dark spots in the corners. The only way I
> can do this is setting so bad values that the image gets blotchy, but that's
> not a very good solution.
>   Does anyone has any good advice?
>
>   It's funny that I got really good values for the radiosity test images
> in my web page, but I can't find them for this image (of course the settings
> for those radiosity test images do not work with this image).
>
> --
> main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
> ):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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