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We no longer support VRGL, but it remains useful, and several installations still use it.

VRGL is a modified OpenGL library, which allows the programmer to introduce off-axis and spherical projection effects into the display of any OpenGL application. It exists as a compiled library, (a *.dll file in Windows(R) which masquerades as the standard OpenGL library the application normally uses. VRGL intercepts the application's OpenGL calls, introduces needed changes, and passes the requests on to the true OpenGL library. VRGL is intended to work closely with CaveUT.

Theoretically, VRGL could work with any OpenGL program, but we have only made sure it works with Unreal Tournament 2004 and earlier versions. Because of this, it is finely tuned to cater to the needs of the 2.5 (and earlier) versions of the Unreal Engine produced by Epic Games. VRGL works closely with CaveUT.

VRGL supports moderate spherical warping needed for multi-projector dome displays. The best example is the Earth Theater's partial dome display which uses standard LCD projectors, VRGL 2.5 for the warping, and CaveUT 2.5 to handle the multiple projection areas on the main screen. VRGL will function on most modern video cards, employing shader code for better performance. It comes with support for color correction and some degree of edge blending. Finally, VRGL 2.5 continues to support off-axis projections for flat screen displays, the essential building block for multifaceted CAVE-like and video wall displays. We are no longer supporting or developing VRGL. You can get the final version here, along with CaveUT, and a couple of other useful tools.

The older VRGL 1.5 supports single-projector dome displays with UT2004, such as the vision station shown at the top of this page, a small single-projector dome shown in the middle, and the inflatable Discovery Dome. The projection area is limited to approximately 120° in this build software. To use it, you need the VRGL 1.5 installation package, a standard PC with a geForce chipset video card, a fully or partially spherical dome projection surface, and a projector with a special fish-eye lens or a standard projector and a hemispherical mirror. Talk to a dome display provider for more information.

The old VRGL 1.0 is still available, and amazingly continues to work on any geForce chipset video card. Because it is so simple, it makes a good starting point for those who wish to make their own OpenGL fake library application.


Our everlasting appreciation goes to Willem de Jonge, who wrote VRGL 1.0 in 2003. Without it, or something like it, CaveUT and VRGL would never have progressed beyond a student project.

Our utmost thanks to Epic Games for providing to us a read-only license to every version of their Unreal Engine, a powerful software platform for graphics rendering, physics, and networking. While VRGL is technically generic, the needs of the engine are so complex that we had to see the code to understand how to support it.

Bob Kuehne of Blue Newt Software wrote VRGL 2.5 in 2006, making it stable, efficient, and modern.

Since 2004, The Elumenati helped this project in many small but important ways, giving advice, making introductions, helping with testing, and helping with publicity. They provided both of the images on this page.

Our thanks to the Interactive Dome Project team at the Entertainment Technology Center for their help with testing VRGL 1.5 in their small dome.

Suresh Balu built VRGL 1.5 from version 1.0 in 2005, by adding the spherical projection capability. He used Elumens' now defunct SPIClops API for spherical projection. For our next serious rebuild of VRGL, we will use Elumenati's Omnimap software.

Jeffrey Jacobson wrote the precursor to VRGL, a six-line hack in the open header code of the 1999 edition of Unreal Tournament (v436). For all later versions of VRGL, Mr. Jacobson developed the detailed requirements, conducted all testing, wrote all documentation, and supervised the project generally.

Latest News:

Many K-12 dome shows this year funded by Nord Family Foundation, NASA, and NSF. Ancient Greek farmer puppet/avatar. A collaboration with VIZIN Helping with a workshop in digital puppetry.

Archive Project No Longer Active.