The directional resolution of BSDF is of particular importance if the sun is visible through shading systems featuring a direct transmission component. A common example for such systems are fabrics, which transmit a fraction of the incident sun-light without any scattering through the gaps between their comprising fibres. A systematic evaluation of different modeling and simulation methods in comparison with calibrated High Dynamic Range photography was performed and led to a simulation technique achieving accordance with RMSE < 10% for Daylight Glare Probability evaluations.
The results of the joint research by LBL, EPFL, Bartenbach and HSLU were presented at the International Radiance Workshop in Loughborough in September 2018.
Lee, Eleanor; Wang, Taoning; Jonsson, Jacob; Ward, Gregory; Grobe, Lars Oliver; Wienold, Jan & Geisler-Moroder, David (03.09.2018). Generating high-resolution BSDFs for the direct beam component. 2018 International Radiance Workshop, Loughborough, UK (https://www.radiance-online.org/community/workshops/2018-loughborough/presentations/03-HighResBSDFs.pdf)