POV-Ray : Newsgroups : povray.unofficial.patches : photon mapping problem : Re: photon mapping problem Server Time
2 Sep 2024 08:18:03 EDT (-0400)
  Re: photon mapping problem  
From: daishi
Date: 5 Apr 2000 12:41:28
Message: <38EB6AFC.D09DE447@x-press.net>
I tried setting the spacing to 1, and the autostop to .5 (oh btw if I use count
it doesn't generate the photon map either, I've even tried 2 million photons and
it still wouldn't generate the map)
about 38k photons hit the object, and it just keeps shooting them forever
(meaning the amount of photons that actully strike the object never goes up)

it seems if I specifiy an autostop greater then 0 it will continue to shoot
photons at the object for an infinate amount of time, if I specifiy autostop 0
though it doesn't even build the photon maps....

ugh, I don't have any infinate objects in my scene, just 2 polygon mesh's the
object and the floor, and just to be sure the floor wasn't the problem I put
ignore_photons in the object declaration

Nathan Kopp wrote:

> daishi <das### [at] x-pressnet> wrote...
> > b) never stops building the map, it gets to about 78500 photons hit the
> > object and then it just continues to shoot photons, but the number of
> > photons that actully strike the object never goes up and it just keeps
> > shooting photons at it until it runs out of memory (it tried to
> > allocated 327mb for the photon map)
>
> If you're using spacing (as opposed to count), use a larger spacing.  Also,
> try manually bounding the object (as previously suggested, and make sure you
> tell POV not to remove your manual bounds).  Finally, use an autostop of 0.5
> or so.  Autostop of zero doesn't work because the object has a hole in the
> middle.  If the photons quit striking the object, POV shouldn't try to
> allocate any more memory.  WinMegaPov displays a total number of photons as
> it builds the map, and if that number stops going up (meaning that the
> remaining photons are missing their target), you shouldn't get any more
> memory allocated for the photon map.
>
> -Nathan


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