UCLA VIRTUAL WORLD DATA SERVER PROJECT

Richard R. Muntz*
Walter Gekelman**
William H. Jepson***
Walter Karplus*
D. Stott Parker*

(*) Computer Science Department
University of California, Los Angeles

(**) Physics Department
University of California, Los Angeles

(***) Department of Architecture & Urban Design
University of California, Los Angeles

Contact Information

Richard R. Muntz
3732 Boelter Hall
Computer Science Dept., UCLA
Los Angeles, CA 90095-1596
City, State ZIP
Phone: (310) 825-3546
Fax : (310) 825-2273
Email: muntz@cs.ucla.edu

WWW PAGE

http://mml.cs.ucla.edu

Keywords

Multimedia Data Server, Real-time I/O, Randomized Data Allocation, 3D Virtual World, Video on Demand, Scientific Visualization.

Project Award Information

Award Number: IRI-9527178
Duration: 3rd year
Title: UCLA Virtual World Data Server Project

Project Summary

We have developed a general real-time multimedia data server using parallel disks, that can simultaneously deliver data to heterogeneous applications with real-time requirements, such as 3D interactive virtual worlds, interactive scientific visualizations, video on demand, etc.

Goals, Objectives, and Targeted Activities

The goals for the next year include:

Finish porting our current working version of the Virtual World Data Server to a distributed architecture based on a cluster of commodity PCs.
We have developed some new approaches to traffic shaping, admission control and scheduling that are particularly tailored to the continuously interactive type of application represented by interactive visualization. In the coming year, implementation and evaluation of these schemes will be completed.
Continue work on optimization of the 3D interactive urban simulation application in order to reduce the current bandwidth requirement of individual "fly through" sessions. This will include, compression and progressive transmission of texture images, development of back facing culling algorithms that will avoid retrieving unnecessary objects that are not currently visible, and possibly other techniques to be determined.
Finish development of the infrastructure necessary to make the VWDS available to the UCLA scientific community to store and deliver data for both real-time and non real-time scientific applications that require high storage capacity and bandwidth. Potential users include researchers at the departments of Architecture & Urban Design, Atmospheric Sciences, Neural Science and Physics.

Indication of Success

A prototype of the VWDS Data Server supporting simultaneous delivery of MPEG encoded videos and 3D urban simulation city models for multiple users has been implemented and successfully demonstrated at several events. Demonstrations, presentations and talks have been invited at more than 50 events including:

ACM 50th Anniversary Celebration.
ACM Multimedia 98.
IEEE Computer Performance and Dependability Symposium.
Workshop on Distributed Interactive Simulation and Real Time Applications.
Multimedia Information Systems Workshop, West Point, New York.
Internet 2 Demo, Washington DC, April 1998.
The American Planning Association (APA) National Conference.
The California and Los Angeles Chapter's of the APA annual conferences.
The Washington State Chapter of the APA annual conference.
The A/E/C (architecture, engineering, construction) Systems Conference.
I/ITSEC '97 (the Interservice/Industry Training, Simulation and Education Conference).
Intel's National Conference on Graphics.
Schloss Dagstuhl, Germany.
ACADIA (Association for Computer Aided Design in Architecture, National Conference).
Council for Technology and the Individual, Roundtable in Multimedia Visual Simulation and Interaction Conference.
FAA, Los Angeles, CA.
National Meeting American Planning Association.
Los Angeles Emergency Preparedness.
Museum Computer Network Conference.
Virtual Worlds and Simulation Conference.
Los Angeles Police Department.
California Institute of Technology.
Harvard University.
Massachusetts Institute of Technology.
University of Pennsylvania.
University of Washington.
Columbia University.
Yale University.
University of Pennsylvania

Project Impact

The project has enabled collaborations with the following organizations:

Intel Corporation
Microsoft Corporation
Silicon Graphics Inc.
MultiGen Inc.
Bay Networks
Mayor's Office, City of Los Angeles
Los Angeles Police and Fire Departments
Los Angeles World Airports
Metropolitan Transportation Authority (Los Angeles)
Los Angeles Community Redevelopment Authority
Getty Information, Conservation, Education and Antiquities Institutes
San Diego Supercomputer Center

The project has provided research opportunities for several graduate students. Jose Renato Santos graduate with his Ph.D this past year. Chris Mitchell graduated with his Masters degree in CS. Current graduate students working in the project are: Damon Liu, Wai-Man R. Wong, Yasuyuki Sato, and Scott A. Friedman, all in the Ph.D. Program, UCLA CS Department.

A two-quarter course curriculum devoted entirely to real-time Urban Simulation has been developed and taught in UCLA Department of Architecture and Urban Design. Courses in high performance storage systems and multimedia information systems have been developed and taught in the CS Dept.

Project References

J.R. Santos, R. Muntz. "Performance Analysis of the RIO Multimedia Storage System with Heterogenious Disks". 6th Int'l. ACM Multimedia Conference (ACM Multimedia 98)., Sept. 1998.

R. Muntz, J.R. Santos, S. Berson. "A Parallel Disk Storage System for Real-time Multimedia Application". Special Issue on Multimedia Computing Systems of the International Journal of Intelligent Systems, Dec. 1998.

F. Fabbrocino, J.R. Santos, R. Muntz. "An Implicitly Scalable Real-Time Multimedia Storage Server". Int'l Workshop on Distributed Interactive Simulation and Real Time Applications (DIS_RT), July, 1998. March 1998.

W. Jepson, S. Friedman. "An Efficient Environment for Real-Time Visualization". I/ITSEC '97 19th Interservice/Industry Training Systems and Education Conference, Orlando, Florida, December 1997.

W. Jepson, S. Friedman. "Virtual LA, Urban Simulation in Los Angeles". Planning Magazine, July, 1998.

W. Jepson, S. Friedman. "SimCity of Angeles". Civil Engineering, Journal of the Amer. Soc. of Civil Engineers, June, 1998.

F. Hamit. "The Urban Simulation Lab's Image-Based Model of the Future of Los Angeles". Advanced Imaging Magazine, July, 1998.

A. Emmett. "Virtual Journeys". Computer Graphics World, May, 1998.

A. Sullivan. "Urban Simulations". Architecture Magazine, May, 1998.

R. Chan, W. Jepson and S. Friedman. "Urban Simulation: An Innovative Tool for Interactive Planning and Consensus Building". Proc. American Planning Association National Conference, April, 1998.

B. Marovic. "Interactive Visualization of 3D Fields and Images Using VRML". Proc. Medicine Meets VR, Jan. 1999.

Area Background

We address the problem of storing and delivering data to multimedia real-time applications. These applications access large amounts of data that typically do not fit in main memory and need to be continuously retrieved from disks. These continuous media data impose deadlines on the retrieval and delivery of information, which must be satisfied to avoid undesired discontinuities on data visualization by the end user. High utilization of resources is desirable to achieve a good cost/performance ratio. However, high utilization is inconsistent with guaranteed real-time service and statistically varying service requirements.The challenge of real-time data servers is to achieve high utilization of system resources and still be able to guarantee low delay bounds on data delivery.

Most of the work on multimedia storage servers has concentrated on video and audio playback, which has highly predictable access patterns. Once a video playback stream is started, data is sequentially read from the storage system at the playout rate. This predictability is exploited in many video servers that carefully layout data on disk to achieve good load balance and high real-time performance. We, however, consider much more general applications, such as 3D interactive virtual worlds, where the high degree of user interaction makes the workload much less predictable. We have developed and implemented,in our Virtual world Data Server, novel solutions for data storage and retrieval that allows the system to provide statistical real-time guarantees with high utilization of resources, for general workloads with unpredictable access patterns.

Area References

[1] P.W. Agnew and A.S. Kellerman. "Distributed Multimedia". Addison Wesley, 1996.

[2] D.J. Gemmell, H.M. Vin, D.P. Kandlur, P.V. Rangan, L. Rowe. "Multimedia Storage Servers:A Tutorial". IEEE Computer, May 1995, pp. 40-51.

[3] T. Funkhouser and C. H. Sequin, S. Teller. "Management of Large Amounts of Data in Interactive Building Walkthroughs". ACM SIGGRAPH Proc. of the 1992 Symposium on Interactive 3D Graphics. 1992.

Potential Related Projects

Some ideas of future research include:

Extension of the 3D Virtual World application to support "avatars", "virtual/ synthetic actors", dynamic interaction between multiple participants, etc.
Support for delivering heterogeneous media types on a single user session, as for example video, audio or text associated with different 3D objects of a virtual world model.
Authoring systems for "knowledge repositories" oriented around 3D models. For example, enabling scholors of ancient Rome to annotate a model of Trajan's Forum so that it ventually becomes the container for the world's knowledge of this historical site an a resource for students and scholars alike.