Iridescent Surface Rendering with Per-Channel Rotation of Anisotropic Microfacet Distribution

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 reflection path is determined by the microfacet-distribution function (MDF) of the surface. Therefore, different MDF for each light wave channel will produce iridescent colors on the surface. The proposed method employs identical and anisotropic microfacet distribution function(MDF) for each light wave channel. In order to make the rendered surface iridescent, we rotate the identical anisotropic MDF with different angles in accordance with the channels. Because of the anisotropy of the base MDF, the rotated MDFs for light channels are different from each other and iridescent reflection can be easily obtained.