[Radiance-general] Re: -ar, -ad, -as, ahh $#*@!

[Greg Ward]

Hi Rob,

> lemme make sure I understand; these 5 rectangles would define the 
> inside recess of the coffer, yes?  And I would call it out like so:
>
> void polygon coffer.top
> 0
> 0
> 12
> 	0 0 -5
> 	0 10 -5
> 	10 10 -5
> 	10 0 -5
>
> ... and so on?

Actually, you want your rectangles to be the four sides plus another 
one _below_ the coffer, sealing it off from the world, so to speak.  
The idea is that the mkillum replaces these surfaces with illum light 
sources (imposters), whose output distributions mimics the 
coffer/ceiling combination.  You need to make sure that source rays 
can't sneak past this geometry, which is why you want it to make a 
tight seal around your luminaire system.

-G