Light scattering simulations using complex subsurface models

New techniques are presented for simulating complex surface reflection phenomena. The approach involves the modeling of surface and subsurface microstructures, the simulation of how light interacts with this geometry, and the recording of the scattered light as a bidirectional reflection distribution function. Previous light simulation techniques employed in this method are extended to include subsurface refraction and multilayer interference effects. A complicated modeling and simulation example is presented that involves the structure of a hummingbird feather and multilayer interference. Light reflection measurements are recorded from paper samples, and a second modeling and simulation exercise is undertaken in an attempt to reproduce the measured results. In both cases, first order agreement is achieved between the simulations, the available analytical models, and the measured data.