POV-Ray : Newsgroups : povray.unofficial.patches : radiosity pre-trace Server Time
2 Sep 2024 10:16:01 EDT (-0400)
  radiosity pre-trace (Message 1 to 2 of 2)  
From: Fabian BRAU
Subject: radiosity pre-trace
Date: 7 Mar 2000 04:01:18
Message: <38C4C559.2A299621@umh.ac.be>
Hello,

someone can give me an explication for this parameter: 
pretrace_start, pretrace_end (I know this was already in 
megapov 0.3 etc... but I didn't find any good explaination about it).
How this paramater affect the result etc...

Thanks

Fabian.


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From: Nieminen Juha
Subject: Re: radiosity pre-trace
Date: 7 Mar 2000 04:28:10
Message: <38c4cba9@news.povray.org>
This is how I have understood it:

  When doing radiosity calculations povray stores color values in a spatial
tree. It also reads the spatial tree to see if there was already a value
calculated for a point in space near to the current one (if it's close
enough, then it just takes it and doesn't have to calculate it).
  If there are many pre-calculated values in the tree, then the final pass
doesn't have to calculate so many radiosity values and it's faster and
more accurate. For the same reason the second pre-trace pass will be faster
and better than the first one, and so on.
  The more the pre-trace passes, the faster and more accurate the final
render (but also the slower the pre-trace stage).

-- 
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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