The Software used for the Homeworks is called Houdini from SideFx. Upon signing up and installing you will be able to use the free version (apprentice) which comes with no drawbacks accept render resolution caps and watermarks.
We recommend installing the 16.5 version of Houdini. This is due to issues with the use of the Python package Scipy in the newest versions. Please head over to this daily build site to install the 16.5 version.
Why Houdini? It is the leading VFX tool and has, has a nice GUI and comes with a lot of tools and has nice rendering.
Here are some of our previous projects done with Houdini.
Other people:
More cool stuff because of SIGGRAPH