The free open source software “Art of Illusion” features 3D modelling and rendering.
The Software Art of Illusion, developed by Peter Easterman, enables the user to create 3D models using a plugin extension. A number of tutorials as well as extensive documentation are available. The software is covered by the public GNU license and can be downloaded free of charge for Windows, Mac and Unix systems.
Art of Illusion Tutorials by Rage Gently:
(c) Picture & Link: Art of Illusion