Ogre3D

OGRE (Object-Oriented Graphics Rendering Engine) is a scene-oriented, real-time, flexible 3D rendering engine (as opposed to a game engine) written in C++ and designed to make it easier and intuitive for developers to produce applications utilizing hardware-accelerated 3D graphics. The class library abstracts the details of using the underlying system libraries like Direct3D and OpenGL and provides an interface based on world objects and other high level classes.