From 2001 up to 2007, I only used AutoCAD in making 3d models and environments. Not only that this is the only software I know how to use, but the only one I have access to. My job as a CAD operator gave me the opportunity to explore the capabilities of the program. Even though my company does not require us to do 3d modelling, I just did it as a hobby. It is also nice to maintain another set of skills other than drafting.