Modeling specular transmission of complex fenestration systems with data-driven BSDFs

作者：Gregory J. Ward, Taoning Wang, David Geisler‐Moroder, Eleanor S. Lee, Lars Oliver Grobe, Jan Wienold, Jacob C. Jonsson · 发表于：Building and Environment · 年份：2021 · DOI：10.1016/j.buildenv.2021.107774 · 被引用次数：33 · 研究领域：Building Energy and Comfort Optimization、Image Enhancement Techniques、Urban Heat Island Mitigation

A Bidirectional Scattering Distribution Function (BSDF) describes how light from each incident direction is scattered (reflected and transmitted) by a simple or composite surface, such as a window shade. Compact, tabular BSDFs may be derived via interpolation, discretization and/or compression from goniophotometer measurements. These data-driven BSDFs can represent any measurable distribution to the limits of their tabulated resolution, making them more general than parametric or analytical BSDFs, which are restricted to a particular class of materials. However, tabulated BSDFs present a trade-off between higher sampling loads versus lower directional accuracy during simulation. Low-resolution BSDFs (e.g., Klems basis) may be adequate for calculating solar heat gains but fall short when applied to daylight glare predictions. The tensor-tree representation moderates this trade-off using a variable-resolution basis, providing detail where needed at an acceptable cost. Independently, a peak extraction algorithm isolates direct transmission from any tabular BSDF, enabling high-resolution beam radiation and glare analysis through transmitting systems with a “vision” component. Our data-driven BSDF methods were validated with a pilot study of a fabric shade installed in an outdoor, full-scale office testbed. Comparisons between measurement and simulation were made for vertical illuminance, specular and near-specular transmission, and daylight glare probability. Models based on high...