caa a22 4500 605541442 CHVBK 20210128100916.0 cr unu---uuuuu 210128e20151101xx s 000 0 eng 10.1007/s00371-014-1033-3 doi (NATIONALLICENCE)springer-10.1007/s00371-014-1033-3 Yamaguchi Satoshi Graduate School of Computer and Information Sciences, Hosei University, Tokyo, Japan aut A parametric reflectance approximation for rendering Japanese lacquerware and Maki-e [Elektronische Daten] [Satoshi Yamaguchi] This paper proposes a reflectance distribution model that is able to express complex reflections from materials such as Japanese lacquerware and Maki-e to produce highly realistic computer graphics. Our method improves the Ward model for materials with anisotropic reflection, and uses the approximate coefficients calculated from measured reflectance distribution data to reconstruct the actual reflectance. Our research derives a Gaussian distribution summation method and a modified Fresnel reflectance approximation function from measured reflectance data. Our Fresnel reflectance approximation function adds parameters to Schlick's approximation function to control the whole curve and extinction component, and is thus closer to the actual Fresnel reflectance. Based on these functions, a decision process is developed for the approximation coefficients, and this makes it possible to easily reconstruct the actual reflectance. The reconstructed reflectance distributions obtained using these coefficients are compared with measured reflectance data using the L2 norm of the difference. In addition, reconstructed Fresnel reflection effects are compared with those from actual sample materials. Using these coefficient values, this paper shows a sample of simulated Maki-e images under two different lighting environments. Springer-Verlag Berlin Heidelberg, 2014 Reflectance nationallicence BRDF nationallicence Measurement-based Modeling nationallicence Japanese lacquerware nationallicence Maki-e nationallicence The Visual Computer Springer Berlin Heidelberg 31/11(2015-11-01), 1553-1564 0178-2789 31:11<1553 2015 31 371 https://doi.org/10.1007/s00371-014-1033-3 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00371-014-1033-3 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Yamaguchi Satoshi Graduate School of Computer and Information Sciences, Hosei University, Tokyo, Japan aut NATIONALLICENCE 773 0- The Visual Computer Springer Berlin Heidelberg 31/11(2015-11-01), 1553-1564 0178-2789 31:11<1553 2015 31 371