[Radiance-general] Materials definition

[Christopher Rush]

Or, if you already know the glass transmission you want to model, you can calculate transmissivity for the material definition from the total visible transmission (Tn in this formula):
>From http://radsite.lbl.gov/radiance/refer/ray.html#Materials
  transmissivity = (sqrt(.8402528435+.0072522239*Tn*Tn)-.9166530661)/.0036261119/Tn

So, if you want a glass of 90% transmission, replacing Tn with 0.9 gives transmissivity of 0.9801, so your radiance material would look like

void glass glass_90percent_transmission
0 0 3	0.9801 0.9801 0.9801

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