Data-driven models replicate the irregular Bidirectional Scattering Distribution Functions (BSDFs) of optically Complex Fenestration Systems in daylight simulation. RADIANCE employs the tensor tree to store the BSDF at high directional resolution. Its application in backward ray-tracing is however challenging, since the density of stochastic samples must match the model resolution. BSDF proxy and peak extraction address this problem, but are limited to cases when either the fenestration geometry, or the shape and direction of the transmission peak are known. Photon Mapping is proposed to efficiently sample arbitrary BSDFs from the known sun direction. The existing implementation in RADIANCE is extended to account for light sources and their reflections in the field of view, that are of particular importance for visual comfort assessments. The method achieves a high degree of accordance with ray-tracing, and reduces simulation times by ≈95% with data-driven models of high resolution.

Abbreviations: BRT: Backward Ray-Tracing; BSDF: Bidirectional Scattering Distribution Function; CBDM: Climate-Based Daylight Modelling; CFS: Complex Fenestration System; DGI: Daylight Glare Index; DGP: Daylight Glare Probability; FPM: Five Phase Method; GPGPU: General Purpose Graphics Processing Unit; LCP: Laser Cut Panel; OoC: Out-of-Core; PM: Photon Mapping; RMSE: Root Mean Squared Error

数据驱动的模型在日光模拟中复制了光学复杂窗系统的不规则双向散射分布函数（BSDF）。R ADIANCE使用张量树以高方向分辨率存储BSDF。但是，由于随机样本的密度必须与模型分辨率匹配，因此在后向光线跟踪中应用它具有挑战性。BSDF代理和峰值提取解决了这个问题，但仅限于开窗几何形状或传输峰值的形状和方向已知的情况。提出光子映射以从已知太阳方向有效地采样任意BSDF。R ADIANCE中的现有实现扩展到考虑到光源及其在视场中的反射，这对于视觉舒适性评估特别重要。该方法实现了与射线追踪的高度一致性，并且使用高分辨率的数据驱动模型将模拟时间减少了约95％。

缩写： BRT：向后追踪射线；BSDF：双向散射分布函数；CBDM：基于气候的日光建模；CFS：复杂的窗饰系统；DGI：日光眩光指数；DGP：日光眩光概率；FPM：五阶段方法；GPGPU：通用图形处理单元；LCP：激光切割面板；OoC：核心外；PM：光子贴图；RMSE：均方根误差