Thinking in layers: modeling with layered materials

This course serves as a guide to the considerable potential of layered surface models that are available in many commercial products. The key advantage of using such layered materials over traditional shading language constructs is that the end result is highly physically plausible because it simulates real materials more precisely. However, this does not mean that these models cannot be used for artistic purposes. Using simple layered surface models, we demonstrate how a surprisingly large number of interesting and important surface types can be efficiently represented. We also show how handy such an approach is for the end-user, whose main concern is the ease with which one can describe object appearance based only on a few intuitive parameters. We first discuss layered surface models in general and the constraints of modeling object appearance in a physically plausible fashion by explaining basic material properties. We then demonstrate the techniques that are used to analyze such materials, both for high quality offline rendering as well as in a realtime setting. We then give examples of the surface types that can be described in this way and demonstrate how we create them in our company.