[Radiance-general] Re: Glazing transparency/reflectivity study

[Greg Ward]

Yes, well, unfortunately Greg doesn't know what he's talking about,  
because Galen was right when he said that the glaze script demands  
one surface be clear glass.  Your suggestion is better, and should  
work, since the glaze script only uses the transmittance and  
reflectance values for it's models.

Creating a model that properly accounts for the deepening hue  
experienced at off-angle transmission through colored glazing would  
require hand-modeling, since the glaze script only considers a  
surface coating.  I don't know the construction of the Evergreen  
glass, so I'm not sure what's appropriate.

-Greg

> From: Jack de Valpine <jedev at visarc.com>
> Date: January 16, 2009 6:51:56 AM PST
>
> Hi Galen,
>
> It has been a while, but I think that the color/tint comes from the  
> rgb values for the coated glass. So the color would be conveyed by  
> "VE2-2M on Evergreen" monolithic export from Optics 5. So this  
> should account for the color of the coated glass. However, I think  
> that I have to defer to Greg on this for confirmation.
>
> Note for Viracon:
> <type><color>-<transmittance>
>
> so
> type = VE = Low-E
> color = 2 = Green
> transmittance = 2M = ~70%
>
> if you want "Evergreen" you need to look at color 8.... so VE8-2M
>
> One way to sanity check is to run a single layer output from glaze  
> and specify s1 as clear and s2 as VE2-2M on evergreen. The last  
> three lines of the material description should give you:
> Rext_r Rext_g Rext_b
> Rint_r Rint_g Rint_b
> Tr Tg Tb
> The rgb components should be the same as those exported from  
> Optics5 (even though you are specifying "clear" for one layer).
>
> Hope this helps.
>
> -Jack