Hi Valeria,
Trans is a quick and easy way to model this type of glazing.
You can use this widget to generate a trans material definition by entering your transmission and reflection parameters: http://gaia.lbl.gov/people/andy/public/transwidget/
However trans does not account for Fresnel effects that reduce transmission of glass at non-normal incidence angles (http://en.wikipedia.org/wiki/File:Amptitude_Ratios_air_to_glass.JPG). So treat trans results with some degree of caution.
If you want to include fresnell effects and diffusion, you might consider use a glass surface and a trans surface one in front of the other. Or you could generate a BSDF and use the new BSDF material.
Hope this helps,
Andy
···
On Apr 27, 2012, at 1:34 PM, Valeria De Giuli wrote:
Dear all,
I have to model a two-pane glass make up with a selective 6mm outer pane with an integrated capillary slab (it is called kapilux), white tinted. The obtained effect is a uniform and diffuse light transmittance. The only technical data that I have are: 30% of direct visible transmittance and 15% of diffuse visible transmittance. I think I should model it with "trans" material, but I don't know which parameters I have to use. Does anybody has an idea?
Thanks in advance. Best regards,
Valeria
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http://www.radiance-online.org/mailman/listinfo/radiance-general
Thank you Andy, this is a quick and useful widget, however in this case I have only direct and diffuse visible transmission, therefore I can only assign the diffuse transmission. Am I right?
Thanks,
Valeria
···
Il giorno 27/apr/2012, alle ore 23:31, Andy McNeil ha scritto:
Hi Valeria,
Trans is a quick and easy way to model this type of glazing.
You can use this widget to generate a trans material definition by entering your transmission and reflection parameters: http://gaia.lbl.gov/people/andy/public/transwidget/
However trans does not account for Fresnel effects that reduce transmission of glass at non-normal incidence angles (http://en.wikipedia.org/wiki/File:Amptitude_Ratios_air_to_glass.JPG). So treat trans results with some degree of caution.
If you want to include fresnell effects and diffusion, you might consider use a glass surface and a trans surface one in front of the other. Or you could generate a BSDF and use the new BSDF material.
Hope this helps,
Andy
On Apr 27, 2012, at 1:34 PM, Valeria De Giuli wrote:
Dear all,
I have to model a two-pane glass make up with a selective 6mm outer pane with an integrated capillary slab (it is called kapilux), white tinted. The obtained effect is a uniform and diffuse light transmittance. The only technical data that I have are: 30% of direct visible transmittance and 15% of diffuse visible transmittance. I think I should model it with "trans" material, but I don't know which parameters I have to use. Does anybody has an idea?
Thanks in advance. Best regards,
Valeria
_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general
_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general
Thanks Zack. you're right. I just switched the labels.
I should also mention that this widget only works on browsers that support web kit: safari & chrome. not firefox. I don't know about IE.
If you're on a mac, you can get it as a dashboard widget here: http://software.mcneilorama.com/Gen_Trans_Widget.html
···
On Apr 27, 2012, at 3:17 PM, Zack Rogers wrote:
Hi Andy,
I think your roughness and absorption input labels are switched in this widget. This is a nice little tool - thanks!
Zack
On Fri, Apr 27, 2012 at 3:31 PM, Andy McNeil <[email protected]> wrote:
Hi Valeria,
Trans is a quick and easy way to model this type of glazing.
You can use this widget to generate a trans material definition by entering your transmission and reflection parameters: http://gaia.lbl.gov/people/andy/public/transwidget/
However trans does not account for Fresnel effects that reduce transmission of glass at non-normal incidence angles (http://en.wikipedia.org/wiki/File:Amptitude_Ratios_air_to_glass.JPG). So treat trans results with some degree of caution.
If you want to include fresnell effects and diffusion, you might consider use a glass surface and a trans surface one in front of the other. Or you could generate a BSDF and use the new BSDF material.
Hope this helps,
Andy
On Apr 27, 2012, at 1:34 PM, Valeria De Giuli wrote:
> Dear all,
> I have to model a two-pane glass make up with a selective 6mm outer pane with an integrated capillary slab (it is called kapilux), white tinted. The obtained effect is a uniform and diffuse light transmittance. The only technical data that I have are: 30% of direct visible transmittance and 15% of diffuse visible transmittance. I think I should model it with "trans" material, but I don't know which parameters I have to use. Does anybody has an idea?
> Thanks in advance. Best regards,
> Valeria
> _______________________________________________
> Radiance-general mailing list
> [email protected]
> http://www.radiance-online.org/mailman/listinfo/radiance-general
_______________________________________________
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[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general
--
Zack Rogers, P.E., LEED AP BD+C
Daylighting Innovations, LLC
211 North Public Road, Suite 220
Lafayette, CO 80026
(303)946-2310
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It's really tough to say without knowing what they mean by direct and diffuse transmission. From their website I understand that by "direct" they mean normal incidence direct-hemispherical transmission and by "diffuse" they mean hemispherical-hemispherical transmission. I would suggest setting Td to 30% and know that for non-normal incidence angles you will over estimate overall transmission.
This product, with it's capillary tubes and diffusing papers, is a perfect example of a system that should be modeled with a BSDF. Unfortunately your options for BSDF characterization are murky at best right now.
Andy
···
On Apr 27, 2012, at 2:47 PM, Valeria De Giuli wrote:
Thank you Andy, this is a quick and useful widget, however in this case I have only direct and diffuse visible transmission, therefore I can only assign the diffuse transmission. Am I right?
Thanks,
Valeria
Il giorno 27/apr/2012, alle ore 23:31, Andy McNeil ha scritto:
Hi Valeria,
Trans is a quick and easy way to model this type of glazing.
You can use this widget to generate a trans material definition by entering your transmission and reflection parameters: http://gaia.lbl.gov/people/andy/public/transwidget/
However trans does not account for Fresnel effects that reduce transmission of glass at non-normal incidence angles (http://en.wikipedia.org/wiki/File:Amptitude_Ratios_air_to_glass.JPG). So treat trans results with some degree of caution.
If you want to include fresnell effects and diffusion, you might consider use a glass surface and a trans surface one in front of the other. Or you could generate a BSDF and use the new BSDF material.
Hope this helps,
Andy
On Apr 27, 2012, at 1:34 PM, Valeria De Giuli wrote:
Dear all,
I have to model a two-pane glass make up with a selective 6mm outer pane with an integrated capillary slab (it is called kapilux), white tinted. The obtained effect is a uniform and diffuse light transmittance. The only technical data that I have are: 30% of direct visible transmittance and 15% of diffuse visible transmittance. I think I should model it with "trans" material, but I don't know which parameters I have to use. Does anybody has an idea?
Thanks in advance. Best regards,
Valeria
_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general
_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general
_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general
Is this similar to the translucent panel modeled by Christoph Reinhart and Marilyne Andersen in the following paper?
http://www.nrc-cnrc.gc.ca/obj/irc/doc/pubs/nrcc48165/nrcc48165.pdf
I believe they developed a Radiance description for it.
Cheers,
-Greg
···
From: Andy McNeil <[email protected]>
Date: April 27, 2012 3:42:25 PM PDT
It's really tough to say without knowing what they mean by direct and diffuse transmission. From their website I understand that by "direct" they mean normal incidence direct-hemispherical transmission and by "diffuse" they mean hemispherical-hemispherical transmission. I would suggest setting Td to 30% and know that for non-normal incidence angles you will over estimate overall transmission.
This product, with it's capillary tubes and diffusing papers, is a perfect example of a system that should be modeled with a BSDF. Unfortunately your options for BSDF characterization are murky at best right now.
Andy
On Apr 27, 2012, at 2:47 PM, Valeria De Giuli wrote:
Thank you Andy, this is a quick and useful widget, however in this case I have only direct and diffuse visible transmission, therefore I can only assign the diffuse transmission. Am I right?
Thanks,
Valeria
Il giorno 27/apr/2012, alle ore 23:31, Andy McNeil ha scritto:
Hi Valeria,
Trans is a quick and easy way to model this type of glazing.
You can use this widget to generate a trans material definition by entering your transmission and reflection parameters: http://gaia.lbl.gov/people/andy/public/transwidget/
However trans does not account for Fresnel effects that reduce transmission of glass at non-normal incidence angles (http://en.wikipedia.org/wiki/File:Amptitude_Ratios_air_to_glass.JPG). So treat trans results with some degree of caution.
If you want to include fresnell effects and diffusion, you might consider use a glass surface and a trans surface one in front of the other. Or you could generate a BSDF and use the new BSDF material.
Hope this helps,
Andy
On Apr 27, 2012, at 1:34 PM, Valeria De Giuli wrote:
Dear all,
I have to model a two-pane glass make up with a selective 6mm outer pane with an integrated capillary slab (it is called kapilux), white tinted. The obtained effect is a uniform and diffuse light transmittance. The only technical data that I have are: 30% of direct visible transmittance and 15% of diffuse visible transmittance. I think I should model it with "trans" material, but I don't know which parameters I have to use. Does anybody has an idea?
Thanks in advance. Best regards,
Valeria
Thank you all! Yes, the product I have to model is the Kapilux. I'm going through the report of Christoph and Marilyne: I think that product is very similar to the one I have to simulate. I have decided to model it following the second option (trans 16%), using the diffuse-diffuse transmittance instead of the direct normal hemispherical (30% in my case). I then put the same values for the other parameters. Do you think it is correct?
Thanks a lot,
Valeria
···
Il giorno 28/apr/2012, alle ore 04:28, Greg Ward ha scritto:
Is this similar to the translucent panel modeled by Christoph Reinhart and Marilyne Andersen in the following paper?
http://www.nrc-cnrc.gc.ca/obj/irc/doc/pubs/nrcc48165/nrcc48165.pdf
I believe they developed a Radiance description for it.
Cheers,
-Greg
From: Andy McNeil <[email protected]>
Date: April 27, 2012 3:42:25 PM PDT
It's really tough to say without knowing what they mean by direct and diffuse transmission. From their website I understand that by "direct" they mean normal incidence direct-hemispherical transmission and by "diffuse" they mean hemispherical-hemispherical transmission. I would suggest setting Td to 30% and know that for non-normal incidence angles you will over estimate overall transmission.
This product, with it's capillary tubes and diffusing papers, is a perfect example of a system that should be modeled with a BSDF. Unfortunately your options for BSDF characterization are murky at best right now.
Andy
On Apr 27, 2012, at 2:47 PM, Valeria De Giuli wrote:
Thank you Andy, this is a quick and useful widget, however in this case I have only direct and diffuse visible transmission, therefore I can only assign the diffuse transmission. Am I right?
Thanks,
Valeria
Il giorno 27/apr/2012, alle ore 23:31, Andy McNeil ha scritto:
Hi Valeria,
Trans is a quick and easy way to model this type of glazing.
You can use this widget to generate a trans material definition by entering your transmission and reflection parameters: http://gaia.lbl.gov/people/andy/public/transwidget/
However trans does not account for Fresnel effects that reduce transmission of glass at non-normal incidence angles (http://en.wikipedia.org/wiki/File:Amptitude_Ratios_air_to_glass.JPG). So treat trans results with some degree of caution.
If you want to include fresnell effects and diffusion, you might consider use a glass surface and a trans surface one in front of the other. Or you could generate a BSDF and use the new BSDF material.
Hope this helps,
Andy
On Apr 27, 2012, at 1:34 PM, Valeria De Giuli wrote:
Dear all,
I have to model a two-pane glass make up with a selective 6mm outer pane with an integrated capillary slab (it is called kapilux), white tinted. The obtained effect is a uniform and diffuse light transmittance. The only technical data that I have are: 30% of direct visible transmittance and 15% of diffuse visible transmittance. I think I should model it with "trans" material, but I don't know which parameters I have to use. Does anybody has an idea?
Thanks in advance. Best regards,
Valeria
_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general
