Well, if you still have those people around maybe this can help you out: Did you know that there are several open source 3D engines and physics engines out here?I had worked with some people, 8 of us total (astral studios) in which we had a real chance of making a game that people would like to play. It was single-player with a SystemShock meets Halo kind of feal to it. Most of the people in our group were doing Balasitic Simulations for BAE Systems, so it was small in crowd of physics majors.... it is easy to set a vision and get people to contribute ideas, be excited and drink lots of beer. It is a hard thing to get people to agree on the details. Razz Astral Studios is still around, but the game never took off outside of header files and some 3d engine source code. Game design can be fun, but when it gets to implementation... you need a strong work ethic to see it through.
The most open graphic engine is irrlicht http://irrlicht.sourceforge.net/ . It works on windows, linux and mac, it has both OpenGL and DirectX in it, and it has the best license of all: You can do anything you want with the engine as long as you credit an author http://irrlicht.sourceforge.net/license.html . Engine has tons of features supports shaders, you can generate a terrain using heightmaps etc.
Second option is OGRE engine http://www.ogre3d.org . It is based on OpenGl. It lokks somewhat cooler than irrlicht, but it has more restrictive license: Although you can use engine in commercial projects and you do not need to publish a source code of your game, if you change the engie, you have to publish changed version.
About physics engines:
There are several but best option is probably ODE engine http://www.ode.org/ . Its license is completely unrestrictive.
Second option is Newton, but it is not open souce. http://www.newtondynamics.com/
good luck.