VIRTUAL ENVIRONMENT ARCHITECTURES:
INTEROPERABILITY AND INFRASTRUCTURE
Table of Contents:
- Principal Investigator.
- Productivity Measures.
- Summary of Objectives and Approach.
- Detailed Summary of Technical Progress.
- Transitions and DOD Interactions.
- Software and Hardware Prototypes.
- List of Publications.
- Invited and Contributed Presentations.
- Honors, Prizes or Awards Received.
- Project Personnel Promotions.
- Project Staff.
- Multimedia URL.
- Business Office.
- Book Plans.
- Sabbatical Plans.
- Related Research.
- PI Name: P. David Stotts
- PI Institution: Univ. of North Carolina
- PI Phone Number: 919 962 1833
- PI Fax Number: 919 962 1799
- PI Street Address: Dept. of Computer Science, CB 3175, Univ. of North Carolina
- PI City,State,Zip: Chapel Hill, NC 27599-3175
- PI E-mail Address: firstname.lastname@example.org
- PI URL Home Page: http://www.cs.unc.edu/~stotts/
- Grant Title: VIRTUAL ENVIRONMENT ARCHITECTURES: INTEROPERABILITY AND INFRASTRUCTURE
- Grant/Contract Number: N00014-94-1-0440
- Mipr Number:
- R&T Number: 1118002RFW02
- Period of Performance: 01 Jan 94 - 31 Dec 96
- Today's Date: 21 Dec 95
- Number of refereed papers submitted not yet published: 3
- Number of refereed papers published: 1
- Number of unrefereed reports and articles: 0
- Number of books or parts thereof submitted but not published: 0
- Number of books or parts thereof published: 0
- Number of project presentations: 4
- Number of patents filed but not yet granted: 0
- Number of patents granted and software copyrights: 0
- Number of graduate students supported >= 25% of full time: 1
- Number of post-docs supported >= 25% of full time: 0
- Number of minorities supported: 0
Summary of Objectives and Approach.
- Virtual reality (VR) is emerging as an important approach to the modeling
and simulation of complex systems. But software technology for scientists
to build VR-based applications fosters development of closed applications
each built from scratch. A scientist's ability to merge models and systems
once developed is solely dependent upon their ability to `hack' software,
since the principles of VR system interconnection are poorly understood and
no software engineering guidelines have ever been developed for use in VR
- We are studying the issue of interoperation between VR systems, that is
the virtual environment, in order to discover essential principles governing
their construction and effective use. Our approach focuses upon the control
properties of interfaces between VR applications: existing VR applications
will be examined in order to expose commonalities, and our abstractions of
VR control behavior will be specified in terms of the software bus model of
interconnection. As principles of VR interoperation emerge, we will build
prototype implementations of corresponding software interconnection tools to
evaluate the application of those principles back in the domains from which
our test problems were drawn. As a result of this research, scientists who
use VR technology will have a sound basis for leveraging existing resources
in new applications, and similarly, they will have an appropriately abstract
framework for specifying how multiple models should be merged operationally.
Detailed Summary of Technical Progress.
- We have developed three prototypes, explained in detail in
following items. Each prototype combined two VE systems of
differing complexity or functionality. In each experiment we
sought to identify the various abstractions in the VE software
architecture that needed to be specified for Polylith manipulation.
- The first prototype involved interconnecting two copies of
one process, a VE allowing building walkthrough using two
joysticks and flatscreen graphics.
We learned which components of the VE datastructures needed to
be exchanged among processes, and found that the overhead of
Polylith did not degrade response time in the VE.
There were no data format or function mismatches to manage.
- The second prototype combined the walkthrough process from
prototype one with a different building walkthrough using
a immersive head-mount I/O environment. There were some
function mismatches that we translated with Polylith calls
but the data formats were the same.
- The third prototype was a maze walking program that
involved multiple immersive VE processes from prototype 2
and several 2-D maze walking processes (supplied by UMD,
running with traditional engineering workstation screen
graphics and controlled from the keyboard).
This interoperating VE had different user interfaces
providing views of one maze: the immersive VEs gave a
3-D view, showing the maze as a "dungeon" with stone walls
floor and ceiling. Other walkers appeared as 3-D figures
in the maze. The 2-D processes showed the same maze from
a "floorplan" view, from above, and the locations of all
walkers were seem at all times. This version has data format
mismatches, user interface mismatches, and function mismatches.
We experimented running this version over the Internet
between UMD and UNC with acceptable results.
- We are developing specifications that allow compact
expression of the abstractions we have identified in
interconnecting the three experimental distributed VEs.
Transitions and DOD Interactions.
- PI is participating in an ARPA CAETI grant in which we are
investigating application of MUD/MOO-style OODB methods to
storage, retrieval, and manipulation of imformation required in
collaborative and interoperating VEs. The CAETI work is leveraging
our results from the ONR grant, and conversely we expect the results
of the CAETI work to have some impact on this ONR project.
Software and Hardware Prototypes.
List of Publications.
- Virtual environment architectures: interoperability through
software interconnection technology.
P.D. Stotts and J. Purtilo.
Proceedings of Third IEEE Workshop on Enabling Technologies:
Infrastructure for Collaborative Enterprises, Morgantown WVa,
IEEE Computer Society Press, (April 1994), pp. 211-224.
J. Duff, J. Purtilo, M. Capps, and D. Stotts,
"Software Engineering of Distributed Simulation Environments,"
submitted to Distributed Somputing Systems '96.
M. Capps, J. Duff, J. Purtilo, and D. Stotts,
"Engineering Interoperable Virtual Environments,"
submitted to VRAIS '96, San Francisco, March 1996.
M. Capps, J. Duff, J. Purtilo, and D. Stotts,
"Software Interconnection for Virtual Environments,"
submitted to Configurable Distributed Systems,
Annapolis, MD, May 1996.
Invited and Contributed Presentations.
- Research presentation, ONR VE grantee meeting, Virginia, March 1995.
- Research presentation, ARPA CAETI/CAPER participants meeting,
George Mason Univ., Sept. 1995.
- Invited talk, Computer Science Dept., William and Mary College,
Williamsburg VA, April 1995.
- Invited talk, Computer Science Dept., Hampton Univ., Hampton
VA, April 1995.
Honors, Prizes or Awards Received.
Project Personnel Promotions.
- Assoc. Professor Stotts (PI) was recommended for tenure at UNC
in Sept. 1995, to be effective Jan. 1996.
- Name: Dr. David Stotts
- Position: Associate Professor, Computer Science Dept., UNC
- Task: Project PI
- QUAD FY95
- The UNC CS Department brochure (print media) for 1995-96
for 1995-96 graduate recruiting features this project.
Here is an
excerpt showing the photos from the brochure.
- Video Tape: We have a short (4 min) video tape
available showing two of our interconnection protoypes in operation.
A copy can be obtained for viewing from
Dr. David Stotts
- software architecture
- module interconnection
- virtual environment
- Business Office Phone Number: 919 962 1777
- Business Office Fax Number: 919 962 1799
- Business Office Email: email@example.com
- Est. FY96: 100%
- FY95: 100%
- FY94: 100%
- FY93: N/A
- Name: Mr. Michael Capps
- Position: Graduate RA, Ph.D. candidate
- Nationality: USA
- Available for Summer at DoD Lab: Yes
- Task: design and implementation of Polylith specs and graphics programs
- Thesis: Interoperabile Virtual Environments
- ARPA CAETI program
or more specifically,
part of it