It is the absolutely best 3D package that I have ever used. I will not say that AM99 is easy to use. As with any complex piece of software, it is necessary to carefully and methodically learn how it works. This is the difficult part. Additionally, Hash Inc. is the most responsive software company that I have ever seen.
Refraction is a link to a web page discussing refraction.
It includes a brief document discussing the physics of refraction and my tests of Animation Master 99 and how it deals with refraction. Max's Toy Box - This is a link to images I have made using AM99 of my son's toys.