Enlight is intended to fill the gap between standard MAX lights and physically based radiosity solutions. Flexible,
user friendly and fast, it is fully MAX/VIZ 3.x compatible and uses the latest enhancements in the MAX software architecture.
With Enlight's Advanced Shadowing System it is very easy to have appropriate illumination and shadowing based upon an objects structure.
Link : http://www.afterworks.com/EnLight.asp