General physically-realistic BRDF models for computing stray light from arbitrary isotropic surfaces
General physically-realistic BRDF models for computing stray light from arbitrary isotropic surfaces
复制标题
用于计算来自任意各向同性表面的杂散光的通用物理真实 BRDF 模型
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
A. W. Greynolds
中科院分区：
文献类型：
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作者：
A. W. Greynolds
25 年前专门针对杂散光计算提出了一种通用 BRDF 模型，该模型自动在所有可能的输入/输出方向上强制执行连续性、正性、互易性和各向同性表面对称性，已在商业光学分析代码中实现。它最初的动机是需要拟合（并可能编目）从抛光光学表面到粗糙漫射黑色的所有测量的 BRDF，合理地将仅面内数据扩展到面外，将数百或数千个测量点减少到相对少量的参数（如玻璃色散公式），以及清理违反物理约束的“马虎”数据或模型。然而，很少有人尝试将 BRDF 与任何实际的表面结构或统计数据联系起来（逆问题）。作为应用示例，该模型成功地将“光滑”阳极氧化铝样品上的数千个测量数据点拟合为 100 系数形式，并将 Aeroglaze Z306 漫射黑色涂料上的数十个测量数据点成功拟合为一般 20 系数形式，然后可能是最简单的 2 参数模型。还提出了变体和其他通用 BRDF 模型。
Proposed twenty-five years ago specifically for stray light computations, a general BRDF model that automatically enforces continuity, positivity, reciprocity, and isotropic surface symmetry over all possible input/output directions has been implemented in commercial optical analysis codes. It was originally motivated by the need to fit (and possibly catalogue) measured BRDFs of everything from polished optical surfaces to rough diffuse blacks, reasonably extend inplane only data to out-of-plane, reduce hundreds or thousands of measurement points to a relatively small number of parameters (like glass dispersion formulas), and cleanup “sloppy” data or models that violate physical constraints. However, there is little attempt to relate the BRDF to any actual surface structure or statistics (the inverse problem). As application examples, the model successfully fits several thousand measured data points on a “glossy” anodized Aluminum sample to a 100-coefficient form and several dozen measured data points on Aeroglaze Z306 diffuse black paint to a general 20-coefficient form then probably the simplest 2-parameter model. Variations and other general BRDF models are also proposed.