Attached Link: http://www.strata.com

Another decent 3D program that you can get for free is Strata 3D. They even have quite a few plugins that can be purchased. They even have a sale for all plugins for $99. If you opt for the Pro version, it has Radiosity as a renderer. Can't touch it without spending a few thousand dollars. I believe the Pro version sells for like $300 or $400. I added their link above