Brown Cave Software History

History of Cave Software at Brown University

3rd party software

1. World Toolkit
   1. Pros: This was the first software we used to drive the Brown Cave when it was installed in 1998. World Toolkit had lots of documentation. It handled synchronization of driving 4 displays in our 1998 Cave. It supported semi-sophisticated graphics such as alpha values and through some mechanism we never understood (though would have liked to) would draw semi-transparent geometries correctly-- normally, semi-transparent geometries are tricky technically to draw because you have to sort geometry back to front. It was scenegraph-based which sometimes was useful and sometimes was a hassle. It could import a variety of CAD models which was useful for some applications like Petra. Artery and Petra ran on WTK, plus some smaller applications. An early version of CavePainting may have run on WTK.
   2. Cons: Some visualization ideas we had we could not implement because WTK did not let us control enough of the rendering engine. It went out of business. There wasn't good support for linux at first, and when we moved from SGI to linux graphics computers it wasn't easy to port applications like Artery and Petra.
2. Ensight Gold (http://www.ensight.com/ensight-gold.html)
   1. Pros: DOE uses this commercial software for visualization at desktops and Caves. LANL in particular uses it for Cave visualization. It is a very high-quality and powerful scientific visualization software.
   2. Cons:Its support for Caves is limited, though, providing: stereo rendering, cluster-graphics support, and a heads-up-display containing a small user-defined subset of its total functionality configured in a text file. No head-tracking is provided. The code is not available for extension/modification.
3. VRJuggler (http://www.vrjuggler.org/)
   1. Pros: University of Iowa has developed and supported this software for many years. It has extensive documentation online and runs on multiple platforms.
   2. Cons: In our experience, it has grown to a large size that makes doing simple things hard. We have found most people want a small stepping stone from OpenGL/Cg to Cave-development and that VR Juggler is too big a step that overwhelms developers.
4. OpenScenegraph
   1. Pros: Juergen Schulze used this for some applications at Brown during his time as a post-doc here. It provides a scenegraph which is helpful for some tasks.
   2. Cons: It cannot drive a Cave, but Juergen used it with Brown's "Inspace-2.0" (see below) to develop "CaveVOX".

Brown-built software

1. DOGL (Distributed OpenGL)
   1. Pros: This was the first software we used to drive the IBM cluster we used in 1998. Dmitri Lemmerman did much of the work on it. It was developed in parallel to Chromium and some of the other solutions to driving graphics clusters. It worked by using an interposed OpenGL library to capture OpenGL calls and distribute them with MPI to the nodes of the cluster. I believe some special additional commands were used to handle setting up a viewpoint for a Cave-like display.
   2. Cons: DOGL fell out of use because of its complexity and need for maintenance.
2. Inspace-2.0 - http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.10.6599
   1. Pros:
   2. Cons: