Identifying Diffraction Effects in Measured Reflectances

Holzschuch, N.; Pacanowski, R.

Identifying Diffraction Effects in Measured Reflectances

Files

031-034.pdf (2.35 MB)

Date

2015

Authors

Holzschuch, N.
Pacanowski, R.

Publisher

The Eurographics Association

Abstract

There are two different physical models connecting the micro-geometry of a surface and its physical reflectance properties (BRDF). The first, Cook-Torrance, assumes geometrical optics: light is reflected and masked by the micro-facets. In this model, the BRDF depends on the probability distribution of micro-facets normals. The second, Church-Takacs, assumes diffraction by the micro-geometry. In this model, the BRDF depends on the power spectral distribution of the surface height. Measured reflectance have been fitted to either model but results are not entirely satisfying. In this paper, we assume that both models are valid in BRDFs, but correspond to different areas in parametric space. We present a simple test to classify, locally, parts of the BRDF into the Cook-Torrance model or the diffraction model. The separation makes it easier to fit models to measured BRDFs.

        @inproceedings{10.2312:mam.20151201
,
booktitle = {Workshop on Material Appearance Modeling
},
editor = {Reinhard Klein and Holly Rushmeier
},
title = {{Identifying Diffraction Effects in Measured Reflectances
}},
author = {Holzschuch, N. and 
Pacanowski, R.
},
year = {2015
},
publisher = {The Eurographics Association
},
ISSN = {2309-5059
},
ISBN = {978-3-905674-83-5
},
DOI = {10.2312/mam.20151201
}
}