Blender is the go-to 3D program when other commercial tools are outside of the budget. It is open-source under a GNU GPL license, which means that it is completely free to use, including for commercial, for-profit purposes. Visit their site and download here: www.blender.org. Blender was founded in 2002 and has grown substantially ever since. It is capable of tackling the entire 3D pipeline along with offering a game engine and a compositor. While it can be a steep learning curve for anyone switching over from other 3D programs, it is a valuable asset and is worth taking the time to learn.