Hi guys yesterday I found this cool soft, in the Ubuntu index... Sweet Home 3d.. Open Source and totally free.
Basically works for make Buildings, but it's really speed make something, only a few seconds and you have a simple building, with inner parts, and models (have an internal library expandible for you self or with another online libraries)...
With a bit of work I think can be use in GLbasic, for make a FPS game or if you want launch renders for backgrounds or another kind of graphics...
Really I find very usefull this soft, micing with another for a better textures and better lighting-
Don't worry if you don't have 3D skills , you don't have to do anything, only launch a couple of lines and put the object where do you want....
http://www.sweethome3d.com/es/importModels.jspFor Linux, Win and Mac and I think they have an online version.