[Radiance-general] translucent panel ( trans material )

[Achim Geissler]

Dear Coralie

 

if you have the full spectro-data, there may be a different path: There is a tool called “glaze” (a script found in the standard radiance installation). With this script, you can convert Optics (“Optics” being the freeware program from the LBNL) spectral data into a more detailed Radiance description (type “BRTDfunc”) by exporting from Optics in “Radiance Format” and then entering this data in the “glaze” script.

 

I am laboring under the possible delusion that this is generally a better description for “advanced” glazing products (and possibly any translucent materials). However, I am quite new at this.

 

Regards

Achim

 

 

From: radiance-general-bounces at radiance-online.org [mailto:radiance-general-bounces at radiance-online.org] On Behalf Of Coralie Cauwerts
Sent: Donnerstag, 17. Dezember 2009 11:01
To: radiance-general at radiance-online.org
Subject: [Radiance-general] translucent panel ( trans material )

 

Hello Everyone,  

 

I know characteristics of a 4mm thick translucent panel (measured with a spectrophotometer). I try to introduce it in RADIANCE.

 

Measurements on the exterior side (glossy) give : 

Transmittance_diffuse = 75.5% and transmittance_spec = 9.1%

Reflectance_diffuse = 7.7%

Absorptance = 7.8%

 

Measurements on the interior side (mat) give : 

Transmittance_diffuse = 81.6% and transmittance_spec = 8.9%

Reflectance_diffuse = 7.8%

Absorptance = 1.6%

 

I’m not sure that I introduced it in RADIANCE in a correct way …

(following formulas p325 in Rendering with Radiance)

void trans vitr_dif

0

0

7     0.71 0.77 0.77 0 0.1 0.99 0.0012

With 

Cr = 0.074

Cg = 0.08

Cb = 0.08

Rd = 0.265*Cr+0.67*Cg+0.065*Cb = 0.07841

Rs = 0

Sr = 0.1

Td = 75.5

Ts = 0.091

 

Thank you for your help !

 

Coralie

 

-----------------------------------------------------------------------------------------
Coralie Cauwerts

Researcher

Université catholique de Louvain

Belgium

 

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