[Radiance-general] 5Phase & proxy geometry

[minchaca]

Hi Andy



Thanks a lot for your help with all my questions. I found the solution to
the last one... (Not really worth mentioning!!)

 :))



Regarding my previous 1st. Question:



I tried to create a *glazing_bsdf.rad* file using one of the cfs.xml files
that we have in the lab. I’ve got the message:

“Unsupported IncidentDataStructure for BSDF”, I assume this means that this
is not a ‘tensor tree high resolution BSDF”.

This might be a silly question but: if there is a way to resample the
tensor tree BSDF into a Klems basis BSDF, is there any way

to do the other way around? Or...perhaps this 'error message' means
something else..?



I thank you in advance for your help again!!



Chantal.


2013/11/1 Andrew McNeil <amcneil at lbl.gov>

> Hi Chantal,
>
> 1.- I’m not sure of the use of the ‘BSDFproxy polygon inside’ included in
>> the glazing_bsdf.rad file.
>>
> The BSDF material is applied to this surface. It allows Radiance to use
> the BSDF data in lieu of sampling the geometry during the direct sun
> simulation.
>
>
>> If the latter was generated by genBSDF and includes already the
>> dimensions of the venetian blind, the model, the glazing, and the thickness
>> is also specified…why do we need to specify the coordinates of the polygon
>> (same of the glow material) in this file?
>>
> The BSDF is not always produced by genBSDF, it can come from WINDOW or
> from measurement as well. But regardless, the intention is that optical
> data in a BSDF file is not specific to a size of window, and so you could
> use it in various sized windows.  For example if lightlouver produces a
> BSDF for their product using genBSDF for one project you might want to use
> it in a 2m window for one project but a 3m window for another. Addtionally
> there may be times when you want to use a different thinckness for the
> simulation.  I can think of probably half a dozen reasons why you might not
> want to use dimensions baked into a BSDF file, an as is typical with
> Radiance we lean towards generalization.
>
>
>>
>>
>> I also wonder if we need to use proxy when only if we have a system such
>> as venetian blinds. Is possible to use it also if we have a daylight system
>> as thick as a glass pane such as lasercut panel 6mm?
>>
> Yes, but it isn't worth it unless you have a good Radiance material model
> for the lasercut panel.  Otherwise you're better off using the BSDF
> (assuming it was measured).
>
>
>>
>>
>> I guess that I can shorten this question by: what would be exactly the
>> function of the proxy geometry?
>>
> The BSDF, even high resolution tensortree BSDFs, are spatially averaged.
>  A venetian blind that is angled to admit stripes of light modeled with
> only a BSDF will result in a rectangular patch of intermediate brightness.
>  Using proxy geometry results in bright sun alternating with dark shadows.
>
>>
>>
>> 2.- Regarding this, in the tutorial you have to rotate the geometry in
>> order to generate the two xml files (section 6.2) my
>> silly-silly-super-silly question is:  what would be the orientation of
>> the resulting xml file? Are we re-orientating it by the last three values
>> of the orientation vector in the glazing_bsdf.rad ?
>>
> The WINDOW XML file standard says inside is +Z outside is -Z, up is +Y.
> In Radiance we use up as +Z and inside and outside, well it depends on the
> space your modeling.
>
>
>>
>>
>> 3.- I have a final question that just came now when trying the 5Phase:
>> What would be the number to use in rcontrib –bn when creating the
>> direct-sun-coefficient-matrix?
>>
>> As I understand, it represents the number of sky patches, and it will
>> generate the values of the RGB in the output file. But, if I use –e MF:6 –f
>> reinhart.cal –b 5186, I obtain a matrix result with 31116 columns, which is
>> the number of sky patches six times? Please tell me where am I wrong.
>>
>
> There should be three values per skypatch (R G and B) I don't know why you
> are getting twice as many.  Can you send the full command you are using?
>
> Andy
>
>
>
>
>
>
> _______________________________________________
> Radiance-general mailing list
> Radiance-general at radiance-online.org
> http://www.radiance-online.org/mailman/listinfo/radiance-general
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.radiance-online.org/pipermail/radiance-general/attachments/20131103/3e601423/attachment.html>