Geowall
Encyclopedia
A GeoWall is a low cost interactive 3D stereoscopic
projection system. It consists of a computer with a dual-output graphics card, two projectors, a rack to hold them, polarizing filters, silver screen, a pair of cheap polarized glasses
for each user, and (optionally) one or two monitors. This can be put together for well under US$10,000, or bought as a turnkey system at a higher price from various vendors. There are equivalent systems under other names e.g. passive 3D display.
This article uses the word 'GeoWall' as a convenient trisyllabic equivalent for "low-cost polarization-based dual-projector interactive 3D stereoscopic system". Interactivity is a crucial aspect to GeoWalls, particularly for real-time data exploration. Without interactivity, a GeoWall is merely a system for viewing 3D films
— a cheap 3D IMAX
on a smaller screen.
GeoWalls are examples of passive Virtual Reality
, in the sense that there is no head tracking. Instead of a complete immersive experience for one user, there is a partial immersive experience for multiple users. This makes it suitable for classrooms, group presentations, and interactive museum shows.
(EVL) at the University of Illinois at Chicago
, home of the Cave Automatic Virtual Environment
(CAVE), when asked by Paul Morin if a stripped-down single-wall CAVE would provide a level of 3D immersion acceptable for exploring geoscience data at a price affordable to smaller institutions like museums and academic departments. So instead of a complete CAVE, it was only a single wall, and being used primarily for geology, it was a "geology wall" or GeoWall.
Shortly after the first GeoWall was built, the GeoWall Consortium was created to support the development and distribution of software and data for the GeoWall users. Today, the GeoWall Consortium remains an active user group, whose members have made available free and/or open-source software, content, and documentation. Over 500 GeoWalls have been built since 2005 and the numbers continue to grow. The GeoWall Consortium can be accessed through its website geowall.org and mailing list.
Nick Schwarz has a list of more GeoWall resources.
Stereoscopy
Stereoscopy refers to a technique for creating or enhancing the illusion of depth in an image by presenting two offset images separately to the left and right eye of the viewer. Both of these 2-D offset images are then combined in the brain to give the perception of 3-D depth...
projection system. It consists of a computer with a dual-output graphics card, two projectors, a rack to hold them, polarizing filters, silver screen, a pair of cheap polarized glasses
Polarized glasses
Polarized 3D glasses create the illusion of three-dimensional images by restricting the light that reaches each eye, an example of stereoscopy which exploits the polarization of light....
for each user, and (optionally) one or two monitors. This can be put together for well under US$10,000, or bought as a turnkey system at a higher price from various vendors. There are equivalent systems under other names e.g. passive 3D display.
This article uses the word 'GeoWall' as a convenient trisyllabic equivalent for "low-cost polarization-based dual-projector interactive 3D stereoscopic system". Interactivity is a crucial aspect to GeoWalls, particularly for real-time data exploration. Without interactivity, a GeoWall is merely a system for viewing 3D films
3-D film
A 3-D film or S3D film is a motion picture that enhances the illusion of depth perception...
— a cheap 3D IMAX
IMAX
IMAX is a motion picture film format and a set of proprietary cinema projection standards created by the Canadian company IMAX Corporation. IMAX has the capacity to record and display images of far greater size and resolution than conventional film systems...
on a smaller screen.
GeoWalls are examples of passive Virtual Reality
Virtual reality
Virtual reality , also known as virtuality, is a term that applies to computer-simulated environments that can simulate physical presence in places in the real world, as well as in imaginary worlds...
, in the sense that there is no head tracking. Instead of a complete immersive experience for one user, there is a partial immersive experience for multiple users. This makes it suitable for classrooms, group presentations, and interactive museum shows.
Origins of the name
The first GeoWall was built in January 2001 by Prof. Jason Leigh at the Electronic Visualization LaboratoryElectronic Visualization Laboratory
The Electronic Visualization Laboratory is a cross-disciplinary research lab at the University of Illinois at Chicago. It brings together faculty and students from the Art and Computer Science departments of UIC...
(EVL) at the University of Illinois at Chicago
University of Illinois at Chicago
The University of Illinois at Chicago, or UIC, is a state-funded public research university located in Chicago, Illinois, United States. Its campus is in the Near West Side community area, near the Chicago Loop...
, home of the Cave Automatic Virtual Environment
Cave Automatic Virtual Environment
A Cave Automatic Virtual Environment is an immersive virtual reality environment where projectors are directed to three, four, five or six of the walls of a room-sized cube...
(CAVE), when asked by Paul Morin if a stripped-down single-wall CAVE would provide a level of 3D immersion acceptable for exploring geoscience data at a price affordable to smaller institutions like museums and academic departments. So instead of a complete CAVE, it was only a single wall, and being used primarily for geology, it was a "geology wall" or GeoWall.
Shortly after the first GeoWall was built, the GeoWall Consortium was created to support the development and distribution of software and data for the GeoWall users. Today, the GeoWall Consortium remains an active user group, whose members have made available free and/or open-source software, content, and documentation. Over 500 GeoWalls have been built since 2005 and the numbers continue to grow. The GeoWall Consortium can be accessed through its website geowall.org and mailing list.
Data Interactively Explored with GeoWalls
GeoWalls have been used to explore data in several domains. Stereo photographs and movies can be viewed on a GeoWall, as well as most 3D models. Here are some examples of other data sets that are freely available. All can be modified to work on regular single-screen computers.- GeoWall Consortium has several visualizations, including
- Global Earthquakes.
- Virtual Harlem : Recreation of the New York suburb from the 1930s. Linux only.
- Interactive San Diego Flythrough
- AstroWall : Simulations of stars orbiting under Newton's Law of Gravity in a Plummer potential, Moon orbit details. Windows only.
- Cosmic Ray Showers : animated simulations showing what happens when a high-energy particle from outer space hits the Earth's atmosphere and creates a shower of other subatomic particles. Windows/Linux.
- Large Scale Structure of the Universe : Hundreds of thousands of galaxies mapped by the Sloan Digital Sky Survey. Windows/Linux.
- Visualization of 3D Mathematics : Surfaces associated with several equations, Klein bottles, etc. Very pretty.
- Black Hole Discovery : Observed and extrapolated orbits of a dozen stars orbiting the center of the galaxy. This data was used by UCLA researchers in a 2000 Nature paper to demonstrate that there is a black hole at the center of the Milky Way. Windows/Linux.
- TerrainFly : simple flight simulator, but over Mars.
- Z-Flux : Interactive, real-time rendering of various astronomical animations, originally designed for educational purposes. Free, Windows.
Nick Schwarz has a list of more GeoWall resources.
Software that works on GeoWalls
- Wallview : a simple 'Powerpoint for GeoWalls' that can display stereo photograph pairs. Very useful, despite interactivity limited to zooming and moving pictures about. Free, Windows only.
- Immersaview : displays 3d data in IV (Open Inventor) and VRML formats, both single models and time-varying model sequences. Comes with demos of ant innards, earthquakes zones, etc. Open Source, Windows/Mac/Linux.
- Partiview : displays large, static or dynamic, particle-based datasets. Particles can be textured. Open Source, Windows/Linux. (Documentation on how to use Partiview on GeoWalls.)
- PokeScope. For aligning pairs of stereo photographs. Commercial, Windows only.
- WalkAbout. For exploring VRML models, particularly for earth science data. Open Source, Windows/Mac/Linux
- gOpenMol. Molecular visualizer for computational chemistry. Works on GeoWalls when run in side-by-side stereo mode. Free, open source, Windows/Linux/Sun/AIX.
- ArcGIS : commercial mapping software. Any ArcScene image can be displayed on a GeoWall.
Graphics Cards for GeoWalls
The following graphics cards have been reported as capable of supporting GeoWalls. Geowall.org says that "on the most general level the graphics card needs to have two monitor outputs to provide output to left and right projector".- NVIDIA GeForce2 Twinview
- NVIDIA GeForce4 Ti4400/Ti4600
- Quadro4 550,700,750, 900 XGL, FX2000
- ATI Radeon X800 XT