1 / 37

Commodity Passive Stereo Graphics

Commodity Passive Stereo Graphics. Vikas Chowdhry Atul Nayak Jason Leigh. Goal. Allow users of Access Grid to immersively share 3D content. Design Criteria. Should be inexpensive for the solution to be feasible and replicable across the AG community. Enter Passive Stereo. What is it?

barid
Download Presentation

Commodity Passive Stereo Graphics

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Commodity Passive Stereo Graphics Vikas Chowdhry Atul Nayak Jason Leigh

  2. Goal Allow users of Access Grid to immersively share 3D content

  3. Design Criteria • Should be inexpensive for the solution to be feasible and replicable across the AG community.

  4. Enter Passive Stereo What is it? • Two projectors are used for the single screen one for each eye's view. • Differently polarizing filters are placed in front of each projector lens. • Users wear polarizing glasses where each lens only admits the light from the corresponding projector.

  5. CircularPolarizers Left Eye Right Eye Passive Stereo Schematics

  6. Advantages of Passive Stereo • Allows us to use DLP projectors. • As compared to CRT projectors these are: • Cheaper. • Brighter. InFocus LP500

  7. Other Advantages • Polarized stereo glasses cost much less than the LCD shutter glasses used in active stereo. • Less fragile (you can stop worrying about collecting the glasses after the show is over).

  8. Constructing An AGAVE

  9. Recommended Hardware Specs • Dual Processor Pentium III 750 Mhz or higher. • Atleast 512 MB RAM.

  10. Hardware Specs • Graphics Card • Should support Twin View • Tested With • GeForce 2 MX. • Alternatives (also tested) • Matrox G450. • Alternatives (currently being tested) • FireGL4. • Radeon. • GeForce4 Ti 4600.

  11. System Software • Linux (tried with Red Hat 7.2 and Suse 7.2). • www.redhat.com • Prefer fvwm window manager for Suse. • www.fvwm.org • Any window manager for Red Hat.

  12. Application Software • Coanim • Collaborative Animator • application for viewing 3D content over AGAVE • provides a  flip-book playback of 3D models • http://www.evl.uic.edu/cavern/agave/coanim.html

  13. Application Software • Coanim • Requires • Linux/SGI • OpenGL Performer • http://www.sgi.com/software/performer/ • CAVElib • www.vrco.com • CAVERNsoft • http://www.evl.uic.edu/cavern/

  14. Application Software • ImmersaView • Open Inventor model viewer for the GeoWall/AGAVE. • The data can be a single Inventor model or a flipbook of models • http://www.evl.uic.edu/cavern/agave/immersaview/index.html Screenshot of Immersaview

  15. Application Software • ImmersaView • Requires • Windows/Linux • fltk (fast and light toolkit). • Open Inventor • http://www.coin3d.org

  16. Projector Alignment • In order for the passive stereo to work, the images from the two separate projectors must match up on the screen. • We usually stack projectors vertically as shown. A typical projector mount setup

  17. Polarizers • Circular • Work better because light is circularly polarized. • Effect is not dependent. on alignment of viewer’s glasses. • Are more expensive. • Required for tracking.

  18. Polarizers • Linear • Less expensive. • Stereo effect gets diminished with movement of viewer’s head.

  19. Polarizers • We use velcro to stick polarizers in front of the projectors. • Use this test pattern file to make sure the projectors are aligned. • http://www-users.cs.umn.edu/~wburdick/geowall/ GeoWallAlignmentImage.ppm.gz

  20. Projector Alignment

  21. Projectors Mount • Front Projection • Easier to setup. • Cannot move too close to the screen as shadow causes loss of immersive experience.

  22. Projectors Mount • Rear Projection • Better utilisation of front space. • Ability to go closer to the screen without shadows disrupting the immersive experience. • Space required behind the screen.

  23. Projection Screen Issues • Standard projection screens do not preserve polarization. • Causes ghosting. • Experimentation has led us to use ``Disney black diffusion film'' (Dbd) for rear projection.

  24. Tracking • Tested “Flock of Birds” head tracking system. • http://www.ascension-tech.com/products/ flockofbirds/ • EVL tracking research. • evl.uic.edu

  25. Cost Of Parts

  26. Added Incentives • Rob Gag (RobGag@tierneybrothers.com) sells Geowall bundle • Contains • Projectors • Mounts • Road Case

  27. Going Beyond Goals • AGAVE is reaching beyond its initial goals. • Being used wherever portability and cost outweigh the need for complete immersion as represented by CAVE.

  28. Geowall Consortium • AGAVE is the basis of Geowall. • Utilizes AGAVE to visualize the structure and dynamics of the earth in stereo. • www.geowall.org.

  29. Geowall/AGAVE at University of Michigan

  30. The Mac AGAVE • Created by Andy Johnson at EVL. • Being used to teach sixth graders scientific enquiry. • Meant to replace more expensive immersadesk being used till now. • Details at: • evlweb.eecs.uic.edu/aej/macagave.

  31. AGAVE in Chile • AGAVE was part of the demos at the Internet2 conference in Chile. • Proof of “Pack and Go” stereo.

  32. Stereo Photography • Used by geologists to document expeditions and sites in stereo. • http://www.evl.uic.edu/cavern/agave/EVLStereo/

  33. Sites that have built AGAVEs • Electronic Visualization Lab, Univ. Illinois at Chicago. • The GeoWall Consortium. • Dept. Geology and Geophysics, Univ. Minnesota. • Dept. Astronomy, Univ. Minnesota. • Institute for New Media Studies, Univ. Minnesota. • Visualization and Digital Imaging Lab, Univ. Minnesota- Duluth. • Dept. of Computer Science and Mathematics, Fond Du Lac Tribal and Community College. • Northern Arizona Univ. • Arizona State Univ. • Dept. of Curriculum and Instruction, Univ. Minnesota. • Eros Data Center, US Geological Survey (USGS). • Dept. of Geological Sciences, Univ. Michigan. • Media Union, Univ. Michigan. • Geological Sciences, Indiana University, Bloomington.

  34. Future • Agave in a box – making installation easier. • Add a GyromouseTM/game controller for intuitive navigation. • Camera based hand and head tracking • Standardize specs.

  35. Future • Make more applications available for AGAVE. • Encourage people to build and deploy AGAVE where cost savings justify lack of immersion as compared to CAVE or immersadesk.

  36. Questions?

More Related