Glass is a shader with built-in optical physics and properties ready to produce realistic glasses.Its main features include reflection-refraction color weightening, reflectivity autobalance based on refraction, internal volume ray calculation, color opacity based on objects volume, Bruster angle calculation and optional extra rays rendering.

You can consider this shader a sort of interface to control raytraced shadows. With this shader you will be able to fake soft-edged shadows without render time penalty, place color on the raytraced shadows and control its saturation, darkness, dropoff, cover area.... A must-have shader.


Bonus shaders™:
The RTS package comes with 3 simple shaders ready to tweak color, ambient and shapes of objects separately. This 3 shaders are a great (and fast!) help combined with Glass and RTShadow shaders, and round-up all the features of the RTS package.