What are the benefits to using UNIX for 3d animation. I am looking into the field, and most places require a strong background in UNIX. Why is this?

Very broad question, short answer, Unix is an efficient operating system especially for number chrunching, etc (although with the amount of CPU firepower, it is hard to argue otherwise).

3D animation is also historically Sun, Unix dominated, packages are probably more mature on these platforms.

It is interesting to note that the CGI for "Titantic" was rendered on a Linux farm and the graphics for "The Matrix" were rendered on a FreeBSD farm.

Aloysius, I noticed in a thread posted earlier that you were thinking about switching up to Mac OS X. I would definatly recommend that you try that before you switch over to linux or another unix flavor. It's a great way to get your feet wet. Also I thought you should know that Mac OS X isn't really as much like linux as it is FreeBSD (a unix derived from the berkely systems distrobution). But it's still very much Mac-like in it's interface, alot less scary for a first time unix experience, and a great way to learn some unix from the command-line interface.