[Radiance-general] trans, pmap and head-ache...

[Lars O. Grobe]

Hi,

I am completely stuck with my attempt to get some rather generic 
diffusor into my scene. I have a room which is lid by a light pipe, and 
to simulate this I use radiance 3.7 with the pmap extension. Everything 
works rather fine. Now I wanted to put some diffusing body under that 
light pipe, and I chosed the trans material to do so. The material 
definition I used should result in a simple diffuse transmitting box:

void trans genericDiffusor
0
0
7 1 1 1 0 0 .5 0

And I applied this to a box:

!genbox genericDiffusor Diffusor60x60 .3 .3 .01 | xform -t -.3 -.3 0

The opening is .6x.6m and centred at the origin, so that my diffusor 
covers only part of it. I want to see the effect of the material... And 
the effect is - somewhat unexpected. The "diffusor"-box appears black in 
my rendering. So is there anything completely wrong in my scene? Is 
there anything I got wrong about trans and surface normals, is it the 
combination of trans and pmap?

CU Lars.