In this paper, we propose an efficient iridescent rendering method. The iridescent colors on a surface is caused by the different reflection paths of rays with different wavelengths. In microfacet-based rendering model, the dominant reflection path of an incident light ray is statistically described by the microfacet-distribution function (MDF) of the surface. Therefore, the iridescent colors on the surface can be produced by applying different MDFs to different light wave channels. However, it is unnatural for a surface to have significantly different reflection properties in accordance with the light waves. Taking those into account, the proposed method employs identical and anisotropic microfacet distribution function(MDF) for each light wave channel, and rotates the identical anisotropic MDF of each channel with its own angle to produce iridescent reflection. The method also employs multi-peak MDF for the simulation of diffraction effects, and can be successfully applied to iridecent surface such as CD-ROM and mother-of-pearl (nacre) furniture. The experimental results demonstrate that the method enables interactive applications such as games or virtual reality softwares to plausibly express various cases of iridescent surfaces.
RenderingIridescent surfaceMicrofacet distribution