Any free useful CAD programs for OpenGL?

Last summer, I began working on a 3D game.
The goal is to shoot a moving dragon with a
tank. I’ve created the tank, the dragon, and a flat patch of grass so far.

The problem is this: Creating the objects
by editing the code with a text editor and
having to calculate where each vertex should
go is just taking too long. And the objects I’ve created still look crummy.

If you know of a free graphics editor that saves 3D images in a format recognized easily by OpenGL programs, just let me know.
images

Check otu OpenFX…or else check out MilkShape…i mean it’s ONLY 20 dollars…and for the power it has that’s basically free

Another one is Blender, which was just purchased by the free software community.