Technical information on the PDC six-surface VR-CUBE system

The Cube

The PDC VR-CUBE (the Cube) is a fully immersive visualization environment, 3m x 3m x 2.5m (W x D x H). The unique feature of this virtual reality system is the display of images on all surrounding surfaces, including the floor and the ceiling.

Because all images must be projected from outside the room, the floor is raised 2.5m to provide space for projectors and mirrors.

To enable projection on the floor from underneath, the floor is made of 40mm-thick acrylic glass. For projection reasons, the glass is covered by the same fabric that covers the walls and ceiling.

One of the Cube's walls serves as a large door, which is hinged on the outside and is swung open to allow access to the room. Just outside the Cube, on the same level as its floor, is a 5x6m platform.

Hardware

Driving the VR-CUBE system is a two-rack SGI Onyx2 with 12 R10000 CPUs, 4GB memory, 100+ GB disk and three InfiniteReality graphics pipes with two 64MB raster managers each. Each pipe manages two of the six surfaces.

The floor and ceiling are currently configured to run with a resolution of 1024 x 1024 pixels at a frequency of 96Hz (i.e. 48Hz per eye, due to stereo projection). The walls run at 1024 x 852 to keep the pixels square and to keep the resolution constant along the edges.

Software

Before the construction of the Cube the VR activity at PDC was centered around an ImmersaDesk. The software platform used was the CAVE libraries (CAVElib) from EVL. The bulk of our local applications are still based on CAVElib, although we also use several other packages in different projects. We intend to continue to use different platforms until the field of VR software has matured and some standards have emerged.

Projects

A number of projects that use the Cube have been initiated. These include science-oriented applications (e.g. analysis of glacier flows, volume rendering of biological data, and flows in a jet engine), and applications from other fields such as architecture.

Infrastructure

Part of the PDC design philosophy is to integrate new resources into an existing infrastructure. At PDC there are no stand-alone systems, but rather a collection of various integrated systems that improve over time. User accounts, file systems, storage facilities, and security systems have been distributed among the different computing resources for several years. The Cube is integrated in the same way and is therefore directly accessible to any PDC user with a suitable project.

Networking

The PDC bulk data transfer network is HiPPI-800 between most of the larger systems, including the SGI Onyx2 driving the Cube. Apart from HiPPI, internal networking topology consists of a mixture of 100Mbit FDDI and FastEthernet.

External connections are excellent, since PDC is directly connected by fiber to KTHNOC, where the main interconnect for both SUNET (Swedish University Network) and NORDUnet (Nordic University Network) is located. Even apart from academic networks, KTHNOC is one of the largest interconnects on the Internet today.