Optics glazing in Radiance

People,

As Greg said, the HEAD compiled correctly this time... maybe it was just
the version I tried.

Lars,

What I am trying to do is to actually compare the BSDF given in Klems basis
by WINDOW, and the one generated in the same basis by genBSDF; based on the
materials from Optics. Since I am not comparing the lighting levels; I
understand that the resolution should not be a problem, right?

Now thinking that *"there are not many cases where both the BRTDfunc and
the glass model as given by Optics make sense, but Optics will not take the
decision"*, is there any documentation about modeling "modern glazing
systems"?; for example, I understand that BRTDfunc are oriented to one
side... How can one deal with the inter-reflections between two glazings?

THANKS VERY MUCH

···

2013/1/30 Lars O. Grobe <[email protected]>

Hi German,

if you model clear glass, (almost) all transmission is direct. This works
very efficient for the glass material type, but in theory requires infinite
resolution for a BSDF if you want the models to match. I think there are
not many cases where both the BRTDfunc and the glass model as given by
Optics make sense, but Optics will not take the decision.

So for anything that you do not have any scatter defined, I'd use glass
(dielectric if not thin and to be approximated as one surface).

BRTDfunc output is fine for anything scattering with the limitations of
BRTDfunc in the ambient calculation. That is where Window6 comes into play,
exporting the BSDF model which is really fully supported by Radiance -
though it has a limited resolution.

Cheers, Lars.

> In the other hand; I am trying to see the difference between the BSDF
generated when modeling a glazing using the "glass" primitive given by
Optics; and the BRTDfunc given by the same program. For now everything
suggest that the second one will need much more rays to converge... am I
right?
>
> I am expecting to see difference in the reflecting part, not in the
transmitted part.

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Did you try the optics2rad script I wrote for this purpose?

-Greg

···

From: Germán Molina Larrain <[email protected]>
Date: January 31, 2013 7:01:53 AM PST

People,

As Greg said, the HEAD compiled correctly this time... maybe it was just the version I tried.

Lars,

What I am trying to do is to actually compare the BSDF given in Klems basis by WINDOW, and the one generated in the same basis by genBSDF; based on the materials from Optics. Since I am not comparing the lighting levels; I understand that the resolution should not be a problem, right?

Now thinking that "there are not many cases where both the BRTDfunc and the glass model as given by Optics make sense, but Optics will not take the decision", is there any documentation about modeling "modern glazing systems"?; for example, I understand that BRTDfunc are oriented to one side... How can one deal with the inter-reflections between two glazings?

THANKS VERY MUCH

2013/1/30 Lars O. Grobe <[email protected]>
Hi German,

if you model clear glass, (almost) all transmission is direct. This works very efficient for the glass material type, but in theory requires infinite resolution for a BSDF if you want the models to match. I think there are not many cases where both the BRTDfunc and the glass model as given by Optics make sense, but Optics will not take the decision.

So for anything that you do not have any scatter defined, I'd use glass (dielectric if not thin and to be approximated as one surface).

BRTDfunc output is fine for anything scattering with the limitations of BRTDfunc in the ambient calculation. That is where Window6 comes into play, exporting the BSDF model which is really fully supported by Radiance - though it has a limited resolution.

Cheers, Lars.

> In the other hand; I am trying to see the difference between the BSDF generated when modeling a glazing using the "glass" primitive given by Optics; and the BRTDfunc given by the same program. For now everything suggest that the second one will need much more rays to converge... am I right?
>
> I am expecting to see difference in the reflecting part, not in the transmitted part.

I forgot about it... heard of if a couple of months ago.

Thanks again Greg!

···

2013/1/31 Greg Ward <[email protected]>

Did you try the optics2rad script I wrote for this purpose?

-Greg

*From: *Germán Molina Larrain <[email protected]>

*Date: *January 31, 2013 7:01:53 AM PST

*
*

People,

As Greg said, the HEAD compiled correctly this time... maybe it was just
the version I tried.

Lars,

What I am trying to do is to actually compare the BSDF given in Klems
basis by WINDOW, and the one generated in the same basis by genBSDF; based
on the materials from Optics. Since I am not comparing the lighting levels;
I understand that the resolution should not be a problem, right?

Now thinking that *"there are not many cases where both the BRTDfunc and
the glass model as given by Optics make sense, but Optics will not take the
decision"*, is there any documentation about modeling "modern glazing
systems"?; for example, I understand that BRTDfunc are oriented to one
side... How can one deal with the inter-reflections between two glazings?

THANKS VERY MUCH

2013/1/30 Lars O. Grobe <[email protected]>

Hi German,

if you model clear glass, (almost) all transmission is direct. This works
very efficient for the glass material type, but in theory requires infinite
resolution for a BSDF if you want the models to match. I think there are
not many cases where both the BRTDfunc and the glass model as given by
Optics make sense, but Optics will not take the decision.

So for anything that you do not have any scatter defined, I'd use glass
(dielectric if not thin and to be approximated as one surface).

BRTDfunc output is fine for anything scattering with the limitations of
BRTDfunc in the ambient calculation. That is where Window6 comes into play,
exporting the BSDF model which is really fully supported by Radiance -
though it has a limited resolution.

Cheers, Lars.

> In the other hand; I am trying to see the difference between the BSDF
generated when modeling a glazing using the "glass" primitive given by
Optics; and the BRTDfunc given by the same program. For now everything
suggest that the second one will need much more rays to converge... am I
right?
>
> I am expecting to see difference in the reflecting part, not in the
transmitted part.

_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general