I'm pretty sure I know why it is overly bright, but I'm not sure right now
exactly how to fix it.  Here's the problem:

     |______________|    glass
------------------------ ground

If the glass is just above the ground, photons will get deposited on
both surfaces.  But they are gathered independly from the scene geometry,
so you end up getting double the photons that you should get.  If you
set the "ignore_photons" flag in the glass, it shouldn't store photons
on the glass, so that should work as a workaround for now (speeds the
render time, too),

Sorry I didn't include any demo scenes.  Once you get a good shooting
density & gather density combination, you can usually just reuse that code
to get started with a new scene.

One way to get rid of artifacts is to increase the jitter amount.  If
that doesn't fix it, it probably is because your glass is a mesh.

Looks great, by the way!

-Nathan

Mike wrote:
> 
> I'm having lots of fun with Nathan's new patch.  He and Ron should get a
> kick out of this one (or anyone else who's read Jensen's papers).
> 
> There's a few artifacts that I think may be there because the glass is a
> mesh. I'm still unsure of the brightness on the base, but I suspect it
> may be that odd phenomenon of light getting brighter before the
> fade_distance is reached.  Not sure though.
> 
> Took about 2 hours of fiddeling to come up with this, most of which was
> learning how to use the patch - word to the wise: don't use photons on
> infinite objects!
> 
> Render time was 38 minutes at 640x480 and AA 0.3.
> 
> -Mike
> 
>   -------------------------------------------------------------------------------
>  [Image]

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