Marcelo de Paiva Guimares paivalsi'usp'br

1
Graphical Interaction Devices for Distributed
Virtual Reality Systems

• Marcelo de Paiva Guimarães paiva_at_lsi.usp.br
• Bruno Barberi Gnecco brunobg_at_lsi.usp.br
• Marcelo Knorich Zuffo mkzuffo_at_lsi.usp.br
• Integrated Systems Laboratory
• Polytechnic School - University of São Paulo -
  Brazil
• 2004

2
Introduction

• The contribution of the present research project
  is to simplify the design of graphical interfaces
  and their interaction with the VR application
• freeing the designer from having to know all the
  details of the individual technologies, and to
  use PDAs as interaction device
• No programming knowledge from the GUI designer

3
Introduction

• The PDA application communicates transparently
  with a cluster, via any underlying network
  system, which processes the events and maintains
  the synchrony of the rendered images in real-time
• the interface and its configuration can be
  changed at run-time
• This solution is part of Glass

4
What is Glass?

• A library for distributed computing
• Extensible and flexible
• Portable and interoperable
• Easy to use and learn transparent
• High performance
• Network protocol independent
• Reliable and fault tolerant
• Completely thread safe

5
Overview

• Written in C
• Easy to interface with C, C, Java, etc
• All functionality is provided by plugins
• Glass core provides internal functionality
• Network system
• Plug-in management (Barriers, Events,Alias...)
• Node management
• Fault tolerant
• If a node dies, Glass detects and deals with it.
• Computation does not stop
• Deadlocks are prevented

6
PDA Editor

• Born from desire to control our CAVE with a PDA
• Glass runs in PDA
• Editor generates GUI in a straightforward,
  graphical way
• No programming knowledge required

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PDA Editor

• Code is generated automatically
• Programmer has only to write an event handler
• Interface is in Java
• Run it anywhere PDA or desktop

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PDA Editor
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PDA Applicaton screenshot

• All input are propagated as asynchronous events,
  which can be either polled or handled by
  callbacks on the application.
• Theres no limit to the number of PDAs that can
  be used simultaneously in an application
• Each PDA may be controlling a different vehicle,
  or the participants may share a GUI and work
  collectively on a project.

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The PDA is a cluster node

• Glass is used underneath
• To Glass, the PDA is just another node

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PDA software layers
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Celestia Application
13
Cathedral Application
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Conclusions

• PDAs
• improve the user interaction in immersive
  environments
• can be used to control the VR system itself
• running applications
• controlling lights and projectors, etc
• Its an efficient way to manipulate large volumes
  of data
• the user is already familiar with the GUI
  approach used

15
Conclusions

• The tool for designing GUIs presented
• which generates code automatically, requiring no
  knowledge of computer programming from the user
• The interface runs on Java, which has the
  advantage of easy portability to any platform
• The routine for treatment of events on the main
  application is also generated automatically

16
Conclusions

• The interface integrates directly with the main
  application, which is running on a cluster.
• As future work, we plan to enhance GUIs to be
  multimedia, including animations and sounds