A Physically Based Anisotropic Iridescence Model for Rendering Morpho Butterflies Photo-realistically

Rendering the brilliant iridescent colors of the Morpho butterflies has been a challenge in computer graphics. The cause of vivid blue color of the wings of these species is not as the result of the pigments of the wing. They are caused by the physical microscopic structures on the scales of the wing. These micro-structures has been studied extensively in various fields by different expertise [Yinlong Sun . 2006] [FOX, D. 1976] [VUKUSIC, P. AND SAMBLES, R.2003]. In this paper I have addressed the problem of rendering the anisotropic iridescence colors of the Morpho butterflies photorealistically. The developed model is physically based and combines two previously presented models; Multi-layer thin film model [Yinlong Sun . 2006] and separate lamellae model [S.KINOSHITA et al. 2002]. Both of those models fail to describe the anisotropic nature of the light reflectance on these structures. The introduced model in this paper produces an anisotropic model with interpolating between those two isotropic models. The model is based on the physical properties and analytical derivations of the microscopic structures of on the scales of the wings. Rendered images with this model match the experimental description [Fox 1976; Simon 1971] of iridescence properties of the Morpho butterflies.