Questions about BSDF

Questions about BSDF

I understood in a simple way BSDF would be a collection of data “Spectral” (transmission, Reflection - Visible band And solar band) of a certain composition in different angles of observation

Please correct me if I am wrong. the behavior of a solar control glass is varied throughout the day depending on the position of the sun. like the image below

credits of this image to jack de valpine visarc

the catalog data that are generated by the manufacturers are laboratory data with standard illuminant of 65 and perpendicular incidence, that is the worst case in terms of performance (higher transmission and less reflection)

my first question is: When I use an annual grid sim with bsdf file in a 3 or 5 phase method, am I considering the actual position of the sun and the actual behavior of the glass in relation to the angle between the two?

if yes, I understand that it is a better approach to assessing light issues.

My second question would be: Based on the understanding that this methodology is effective for light, would it be efficient to determine the annual radiation in this way?

there is some way of accounting for the (dynamic thermal ) behavior of the glass throughout the year, with the objective that this (extra) precision could decrease the thermal load values. instead of establishing shgc fixed and a fixed transmission during the simulation

Are the energy plus and honeybee tools ready to do these calculations?

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If you read, and comprehend, the entirety of Jacob Jonsson’s research from 2007 to 2017 in chronological order, you’ll have the answers to the above questions (and also the one about frits that you asked previously). You will find full text versions of all his papers and reports on that link.
He is arguably the foremost authority in the world on BSDFs and was the primary researcher responsible for the implementation of BSDFs as we use them today in Lighting (and to a certain extent Energy simulations as well).


I’m going to add Andy’s presentation as another reference to learn about BSDF:

and also his tutorial on genbsdf:

If you search the forum you can find similar topics that has discussed using BSDF in both daylight and energy modeling.


Sarith and Mostapha

Thank you very much for sharing these materials, no doubt an incredible deepening, I believe that with this now I have a definite path to follow. this solves my problem with the two topics