How to calculate the ( rtn gtn btn ) values of the material type glass ?

radiance-general
1

Hi Greg,

I don't know how I didn't thought about this. It seems also like quite
an intuituve description!
The results also look like right.

Nevertheless I define how I have proceeded, because there is a step that
could be wrong.

From the hole transmitance spectrum of each glass sample I have just

taken the transmittance values at this wavelengths you said and then
calculated its tn

#glass sample 01

Rot=700nm Tn=40.8 rtn= 18.093
Green=546 Tn=48.13 gtn= 18.813
Blue=436 Tn=42.87 btn= 18.317

void glass smpl_01
0
0
3 0.18093 0.18813 0.18317

And this would be the hole material description of this transparent
glass, als just one layer glass, 10mm thick

Thanks again,

Marina

2

Hi Marina,

The tn formula assumes your Tn values are between 0 and 1, not 0 and 100% -- your results should be:

void glass smpl_01
0
3 0.4449 0.5248 0.4675

Good that you checked!
-Greg

ยทยทยท

From: marina aviles olmos <marina.aviles@gmail.com>
Date: March 17, 2009 9:02:44 AM PDT

Hi Greg,

I don't know how I didn't thought about this. It seems also like quite
an intuituve description!
The results also look like right.

Nevertheless I define how I have proceeded, because there is a step that
could be wrong.

From the hole transmitance spectrum of each glass sample I have just

taken the transmittance values at this wavelengths you said and then
calculated its tn

#glass sample 01

Rot=700nm Tn=40.8 rtn= 18.093
Green=546 Tn=48.13 gtn= 18.813
Blue=436 Tn=42.87 btn= 18.317

void glass smpl_01
0
3 0.18093 0.18813 0.18317

And this would be the hole material description of this transparent
glass, als just one layer glass, 10mm thick

Thanks again,

Marina