[Radiance-general] Re: Modeling Question for Translucent Glass

[Greg Ward]

Hi Nikhil,

As Thomas said in his response, the material should show up in a  
normal rendering.  The best way to model frit glass is to use the  
"glaze.csh" script that I created with funding from Visarc.  For a  
single-pane glazing using a full covering of V-175 white frit, this  
script produces:

############################################
# Glazing produced by Radiance glaze script
# $Revision: 2.7 $
# Material surface normal points to interior
# Number of panes in system: 1
# Exterior surface s1 type: clear glass
# Interior surface s2 type: V-175 white frit
# s2 coating coverage: 1
# Exterior normal hemispherical reflectance: 0.33
# Interior normal hemispherical reflectance: 0.59
# Normal hemispherical transmittance: 0.21
#
void BRTDfunc glaze1_unnamed
10
         sr_frit_r sr_frit_g sr_frit_b
         st_frit_r st_frit_g st_frit_b
         0 0 0
         glaze1.cal
0
11
0.59
0.59
0.59
0.256
0.253
0.251
0.21
0.21
0.21
         -1      1

Try this for now, or run the script yourself to vary the parameters.   
If you can't run the script because you only have a Windows machine,  
then you may be stuck playing around with the "trans" material.

-Greg

> From: "Nikhil Kapur" <nkapur at ctgenergetics.com>
> Date: June 12, 2008 3:14:17 PM PDT
> Hi Greg,
>
> I had a question for modeling in Radiance. I apologize for emailing  
> to you directly. I have posted it on the radiance forum today  
> morning as well, but had not seen any responses and I have a  
> deadline to meet.
>
> Since I am fairly new to Radiance I was trying to model an interior  
> translucent glazing (possibly a frit on the glazing). I looked up  
> the archive posts for help but needed a little bit more guidance on  
> the modeling of the glazing. I am using ECOTECT for the basic  
> geometry and ECOTECT’s Radiance Panel to interface with Radiance.
>
> I am modeling a white translucent glazing with about 50%  
> transmittance using the following parameters:
>
> void trans translucent panel
>
> 0
>
> 0
>
> 7 1 1 1 0 0 0.5 0.2
>
> I would like to know if I am correct in my assumptions or if there  
> is some other way to model a translucent / frit glass (any  
> resources on the web that I can look up)
>
> Additionally, I have not been able to figure how to show this trans  
> material inside the space in the final rendering in Radiance as it  
> is essentially invisible. I was reading up on the illum material  
> type but could not figure out how to apply it to this translucent  
> glazing.
>
>  Any help on this will be appreciated.
>
> Thanks.
>
> Nikhil Kapur
>
> CTG Energetics, Inc
>
> 9 4 9 . 4 2 8 . 6 2 7 1