G3D is an engine for rapid development of 3D applications that allows access to the underlying structure.  This allows you to develop new high-performance algorithms quickly. It has been used in SIGGRAPH papers, commercial games, and military simulators. It provides access to data in popular formats including MPEG, PNG, 3DS, JPG, and X, and contains a native OpenGL GUI.

G3D abstracts OpenGL extensions across vendors and emulates them on older hardware. It automatically minimizes state changes and provides an easy-to-use interface for GLSL shaders and render to texture.