[Radiance-general] splitting a render by light sources

[Francesco Anselmo]

Hi Will,

> i am trying to use radiance to render a relatively simple model
> geometrically - just a simple room, with a box sitting on the floor -
> but with up to 100 or so light sources. but the difference is that i
> want to get a separte image file for each light source - i.e.  hundred
> or so images, with only 1 light on in each. i will then use
> superposition and recombine the images later, allowing me to vary the
> intensities of each light source.
>
> is there any kind of built in functionality in radiance to allow me to
> do this, or do i have to write a shell script or something (and if so,
> can anyone point me towards a good place to learn how! i come from a
> very winndows based background)

Shell scripts would work, but Greg has recently added to Radiance rtcontrib:
http://radsite.lbl.gov/radiance/man_html/rtcontrib.1.html

This man page contains already a good starting example:

"
To generate a pair of images corresponding to two lights' contributions:

         vwrays -ff -x 1024 -y 1024 -vf best.vf | rtcontrib -ffc `vwrays -d -x
         1024 -y 1024 -vf best.vf` @render.opt -o c_%s.pic -m light1 -m light2
         scene.oct

These images may then be recombined using the desired outputs of light1
and light2:

         pcomb -c 100 90 75 c_light1.pic -c  50  55  57  c_light2.pic  >  com-
         bined.pic
"

--
Francesco