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Hardware Resources |
| FLEX Virtual Reality Theater | Motion Capture | Tiled Wall Display | Access Grid | RP System | Haptics |
FLEX Virtual Reality TheaterVirtual Reality (VR) refers to ¡°immersive, interactive, multi-sensory, viewer-centered, three-dimensional, computer-generated environments and the combination of technologies required to build these environments¡± (Cruz, 1995, p. 2). VR Theaters immerse users in the environment they are viewing. The users are not just passive observers in the computer-generated world, but are interacting with the various components of the environment in real-time. Envision's VR Theater (Figure 1) is a Fakespace FLEXTM system featuring three ten-foot by eight-foot panels for rear projection of large-scale 3D images. These movable screens can be easily and rapidly rearranged to form a semi-enclosed room with three walls plus a fourth panel as the floor. This arrangement creates a 3D immersive virtual environment. The VR Theater is also equipped with a state-of-the-art tracking system that allows correct perspective rendering and direct interaction with the virtual environment. A 5 channel speaker system in the corners of this facility further contributes to the effect by adding surround sound cues to the virtual reality environment. Depending on the task at hand, the VR Theater is driven either using a 32-bit Windows PC cluster or a 64-bit dual Opteron Linux PC cluster.
Figure 1: An Envision student using the Chinese Garden application in the FLEXTM
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Motion CaptureThe process of recording a person's movements or other live motion event, and converting those movements into a digital, 3D representation of the motion is called motion capture. The Envision Center houses an STT Motion Captor optical motion capture system (Figure 2) that is operated in collaboration with the Department of Visual and Performing Arts. This system is composed of six infrared cameras on tripods and as many as three linked computers. The motion capture system is portable and is capable of capturing the movements of two people simultaneously. Graduate and undergraduate student groups from the Computer Graphics Technology program at Purdue University used this system to produce an interactive dance performance in association with the Department of Visual and Performing Arts. A solo dancer wore the motion capture suit on-stage during the performance. Data gathered from the suit was used to create imagery which was then projected onto 2 large screens on-stage.
Figure 2. Dancer wearing retro-reflective markers for the motion capture system.
Tiled Wall DisplayThe tiled display wall at the Envision Center is a 12' x 7' high-resolution display made up of a grid of 12 smaller projection displays controlled by many computers working together. The wall is capable of displaying 4096 pixels horizontally and 2304 pixels vertically for a total of 9.4 million pixels ¨C which is about 5 times the resolution found on a typical desktop workstation. The display system is extremely versatile and can be used for 2D, 3D, or stereo production of single, large-scale continuous images (Figure 3). This capability is particularly useful when working with satellite imagery of geographical areas and has immediate implications for Homeland Security and Environment Protection initiatives. The tiled wall can also be used to show different graphics on each individual screen, or utilize a combination of screens in the grid for a variety of media displays. Image generation for the tiled wall is driven by a cluster of 12 high-performance PCs with high-end graphics cards.
Figure 3. An Envision student interacting with the Catalysis application using the tiled wall.
Access GridThe Envision Center places a premium on collaborating with researchers and student groups spread over the entire world. ¡°The Access GridTM is an ensemble of resources including multimedia large-format displays, presentation and interactive environments, and interfaces to Grid middleware and to visualization environments.¡± [Source: http://www.accessgrid.org]. The Access Grid (AG) (Figure 4) allows participants from many geographically distant sites to communicate and collaborate with each other easily and inexpensively. Unlike traditional videoconferencing, AG runs over Internet2, using open source software developed by Argonne National Labs. The software is quite flexible, allowing each site to operate using a variety of hardware setups, ranging from individual laptop-based nodes to large classrooms with multiple projected displays. The AG also allows participants to share more than video streams, by creating shared applications and tools. In the spring semester of 2004, the Envision Center developed an Introduction to Virtual Reality course jointly taught by faculty at Purdue University and Indiana University via the Access Grid. The class was also offered in Fall 2004 between Purdue University and Iowa State University. One of the students in the spring class began development of AGJuggler ¨C a toolkit that allows sharing of virtual environments and stereographics over the Access Grid. AGJuggler has since been released publicly under an Open Source license.
Figure 4. Purdue students in the Fall 2004 Introduction to Virtual Environments class observe a lecture delivered from Iowa State University.
RP System
Information below is provided for creating a rear projected visualization system like the one the Purdue Envision Center uses. Items listed with a * are optional - they are not required for your system to work, but they provide additional functionality you may desire. All pricing given is approximate and based on prices advertised in summer and fall 2003 - as technology changes many of these items may actually decrease in cost. |
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PHANTOM DesktopTM Haptic Device
OMEGA Haptic Device 
The 6-DOF Delta Haptic Device 
The Novint Falcon Haptic Device