Many natural objects, and in particular layered materials, have non-linear reflection behavior along the wavelengths. An accurate representation of phenomena such as interference and color dispersion generally requires a fine spectral representation of light instead of the commonly used RGB components. In this article, we introduce and experiment with a general approach to create similar and convincing effects, with a simple RGB BRDF model. We present a model for both specular and a diffuse reflection, and implement them into software and hardware accelerated rendering process.
