Iridescence i s an optical phenomenon of surfaces in which hue changes in proportion to the angles of observation and illumination I ridescent colors can be ob served o n many biological objects including morpho butterflies and J apanese je w- el beetle s . While ordinary color s are induced by pigments in surface , the iridescent color s are caused by interference of light due to micro structure covering the objects To render iridescences in computer graphics , users need to consider a lot of physical parameters such as index of re f raction or film layer thickness . However, in such input systems, users are diff i- cult to predict re n dering results since iridescence is affected by combination of those many physical factors. In this paper, we propose a color palette based interface for bi ological iridescences rendering with which u sers can pass information for rendering iridescences to system by picking color s instead of by inputting physical data of surface . I ncident angle depen d- ency of r eflect ance spectrum is studied in details to achie ve physically sound simulation and color picking user interface . W e also evaluated our sy s tem through rendering results( of morpho butterflies and Japanese jewel beetles and user study in the latter half of this article.

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