Fahrenheit graphics API

Fahrenheit was an effort to create a unified API for 3D computer graphics. It was designed by Microsoft and SGI to unify Direct3D and OpenGL. Much of the original Fahrenheit project was adbandoned, and SGI eventually gave up on attempting to work with MS. In the end only the scene graph portion of the Fahrenheit system was released, now known as XGS, which disappeared shortly after release.

Microsoft had initially licensed OpenGL from SGI to be put into their Windows NT operating system as its basic 3D system, in keeping with MS's positioning of NT as a workstation-class system.

At the time, the mid-1990s, Microsoft was also investing heavily in a new project aimed at producing tile rendering[?] hardware that they believed would lead to an entirely new level of performance for "low end" machines like PCs. OpenGL's scene graph description system was not well suited to describing a tile based scene, and a parallel effort was underway to produce a new API dedicated to supporting the new hardware.

The new API would actually ship first, as Direct3D. However the hardware was not ready at the time, and the tile based API was not appropriate for the scene graph based video cards that were just starting to become common. The result was that their operating system supported either OpenGL, which was too complex to be supported on common cards, and DirectX, who's architechual decisions meant it was at odds with that same hardware.

Some sort of superset API was an obvious development. In late 1997 both SGI and Microsoft started work on a new system to combine the features of OpenGL and Direct3D into a single "scalable" system, called Fahrenheit. Fahrenheit would include a new scene graph based API that would work on top of either existing system, with no performance penalty when converting down to the underlying system. At the same time, Fahrenheit would offer considerably better high-level interfaces for a more robust object oriented development enviornment.

Fahrenheit became the primary focus of both SGI and Microsoft. SGI dropped work on a number of ongoing projects in favour, including Open Inventor[?], Cosmo3D[?] and [[OpenGL++]], which was being developed by SGI Intel and IBM. A project to generalize the OpenGL scene graph, the Scene Graph API, was then used as the basis for the scene graph of Fahrenheit.

In the end, little came of the project. SGI, worried about the encroachment of NT into its Unix workstation market was trying to position itself as the natural 3D partner for developers on MS platforms, but were never able to do this and today are a shadow of their former selves. MS in the meantime continued to develop Direct3D to the point where it included all of the low end functionality of OpenGL, and then cut their ties with SGI completely. OpenGL support was dropped from Windows 2000.

Scene Graph was released as XGS in June 2000. No new versions were ever released, and all of the pages related to either Fahrenheit or XGS on both the Microsoft and SGI web pages have since disappeared.