[Radiance-general] photomapping example

[Lars O. Grobe]

Hi Nassif!
> I am planning to simulate a simple geometry using photomapping.
>
> Is there any simple script of how photo-mapping works? my aim is to 
> check the output for different material (glass, prism, trans...) 
> feeded with a narrow beam Fixture which results different outputs.
Start with Roland's documentation of the pmap extension for Radiance. It 
explains most. Especially look for the supported / unsupported 
primitives. Than, vary the number of photon in the distribution pass 
(try up to 2,000,000 photons) and the bandwith in the photon gather 
pass. Basically, pmap is not too different from using Radiance, you just 
create the photon maps with mkpmap first and use them instead of the 
ambient calculation in rpcit / rtrace. Don't forget to manually delete 
the photon maps, they are not overwritten by mkpmap (adding a --force / 
-f option for overwriting would be a useful add-on...).

I showed some examples at a presentation two years ago:
http://www.radiance-online.org/community/workshops/2010-freiburg/PDF/PmapAppsPresentation-20100922.pdf

There are several presentations on the pmap around for the recent 
workshops, all available at radiance-online.org.

Cheers, Lars.