02005nas a2200277   4500000000100000000000100001008004100002260001200043653005100055653003300106653001600139653001200155100001700167700001600184700002600200700001500226700001800241700001600259700001700275700001700292245010500309300001100414490000800425520128000433022001401713       2022                            d  c03/202210aBidirectional Scattering Distribution Function10acomplex fenestration systems10adaylighting10awindows1 aGregory Ward1 aBruno Bueno1 aDavid Geisler-Moroder1 aLars Grobe1 aJacob Jonsson1 aEleanor Lee1 aTaoning Wang1 aHelen Wilson00aDaylight simulation workflows incorporating measured Bidirectional Scattering Distribution Functions  a1118900 v2593 aDaylight predictions of architectural spaces depend on good estimates of light transfer through skylights, windows and other fenestration systems. For clear glazing and painted surfaces, parametric transmission and reflection models have proven adequate, but there are many cases where light-scattering, semi-specular shading and daylighting materials defy simple characterization. Something as commonplace as fabric roller shades and venetian blinds may turn daylight prediction into guesswork, and numerous advanced systems on the market tuned specifically to enhance daylight are not sufficiently characterized to distinguish their performance. In this paper, we describe new tools available to handle novel and specialized fabrics, materials, and devices using data-driven modelling of bi-directional scattering distribution functions (BSDFs). These representations are usually tabulated at constant or adjustable angular resolution for efficient point-in-time and annual daylight simulations. We describe a variety of BSDF simulation workflows, including some of the tools and methods that make advanced analysis possible, and highlight some of the current challenges. We conclude with a discussion of future work and how such data might be created and shared worldwide.  a0378-7788