Toward a Perceptually Based Metric for BRDF Modeling
Toward a Perceptually Based Metric for BRDF Modeling
复制标题
建立基于感知的 BRDF 建模指标
DOI：
10.2352/cic.2012.20.1.art00025
复制
发表时间：
2012
影响因子：
2.5
通讯作者：
Jinwei Gu
中科院分区：
文献类型：
--
作者：
A. Forés;J. Ferwerda;Jinwei Gu
在计算机图形学中，测量材料用于增强合成图像的真实感。它们通常近似于分析模型，以提高存储效率并允许重要性采样。然而，在优化过程中使用的误差度量不具有感知基础，并且所获得的结果并不总是对应于最佳视觉匹配。在本文中，我们提出了第一步创建一个基于感知的BRDF建模度量。首先，用不同的误差度量和分析BRDF模型近似一组测量的材料。接下来，进行心理物理学研究以比较使用不同误差度量和模型获得的视觉保真度。这项研究的结果表明，立方根度量导致一个更好的感知近似比其他RMS为基础的指标，独立的分析BRDF模型使用。与基于RMS的度量相比，对于尖锐的镜面波瓣获得了使用立方根度量的更多益处，并且随着镜面波瓣加宽，使用立方根度量的益处减小。立方根误差度量的使用将提高使用BRDF近似的渲染的视觉保真度，并扩展测量材料在计算机图形学中的使用。
Measured materials are used in computer graphics to enhance the realism of synthetic images. They are often approximated with analytical models to improve storage efficiency and allow for importance sampling. However, the error metrics used in the optimization procedure do not have a perceptual basis and the obtained results do not always correspond to the best visual match. In this paper we present a first steps towards creating a perceptually-based metric for BRDF modeling. First, a set of measured materials were approximated with different error metrics and analytical BRDF models. Next, a psychophysical study was performed to compare the visual fidelity obtained using different error metrics and models. The results of this study show that the cube root metric leads to a better perceptual approximation than other RMS based metrics, independently of the analytical BRDF model used. More benefit of using the cube root metric compared to the RMS based metrics is obtained for sharp specular lobes, and as the specular lobe broadens the benefit of using the cube root metric decreases. The use of the cube root error metric will improve the visual fidelity of renderings made using BRDF approximations and expand the usage of measured materials in computer graphics.