[Radiance-general] Some trans oddities

Mon, 12 May 2003 16:40:25 -0700

Hi Rob,

Carsten is right about the ambient (-av) settings, but I don't think 
that's your problem.  My guess is that you're running up against the 
ray weight limit Radiance imploys to trim its calculation, which is 
controlled by the -lw parameter.  You should reset this to -lw 0 in 
your tests, or something very small such as -lw 1e-8 if -lw 0 takes too 
long.

Try it.
-Greg

> From: Rob Guglielmetti <[email protected]>
> Date: Fri May 9, 2003  9:28:25  AM US/Pacific
> To: [email protected]
> Subject: [Radiance-general] Some trans oddities
> Reply-To: [email protected]
>
> I am struggling to understand some seemingly inconsistent results I'm 
> getting with the trans material.  We are doing some fairly complex 
> studies of the daylight penetration in a bunch of art galleries.  
> These galleries receive daylight that is filtered through some diffuse 
> glass, and further modulated with sun control shades. It is the 
> material properties of these shades that is giving me fits at the 
> moment.  In brief, certain shade transmissions give wacky results, 
> while most perform as expected.  To reduce the possibility of error, I 
> have constructed a simple box room (16'x16'x9'), with a single 3' 
> square aperture in the ceiling.  this aperture has two panes of 
> diffuse glass (as the real building will), between which I have a 
> polygon that I assign various shade materials (using trans) to.  I am 
> then computing the horizontal illuminance on the floor with rtrace for 
> each shade.
....