[Radiance-general] Problem with Trans material

[Andrea Zani]

Hi everyone,

I am trying to generate a BSDF of a complex translucent facade component.
One of the materials in the model is a fabric and I'm trying to simulate
its optical behavior using a Trans material, however I have some problems.
Creating a BSDF of the trans material (you can see the material definition
below), I have obtained a particular angular transmission behavior as
showed in the pictures below. There is a particular increment between 0°
and 30° of the incidence angle, instead i was expected something similar to
the dashed lines in the graphs. Is it normal to have this angular
transmission trend? If not, how can I fix this problem?

[image: Immagine incorporata 1]

Trans material
void trans Fabric
0
0
7 0.8 0.8 0.8 0.01 0 0.45 0

BSDF:
genBSDF -n 4 -c 4000 -dim 0.299 0.338 0.373 0.429 -0.018 0 -r -ab 10
trans_test_tr3.rad
For the test the material geometry is a rectangle.


Thanks in advance.
Best

-- 

*Andrea Zani*

Meng  |  Phd Student & Researcher



*Politecnico di Milano*

via Ponzio, 31 | 20133 Milano | Italia

*t* +39 02 2399 6015

*@: *andrea.zani at polimi.it

*@: *andrea89.zani at gmail.com

www.polimi. <http://www.polimi.it/>it
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