Marcelo de Paiva Guimarães paiva@lsip.br Bruno Barberi Gnecco brunobg@lsip.br

1. Graphical Interaction Devices for Distributed Virtual Reality Systems Marcelo de Paiva Guimarães paiva@lsi.usp.br Bruno Barberi Gnecco brunobg@lsi.usp.br Marcelo Knorich Zuffo mkzuffo@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

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

8. PDA Editor:

9. PDA Applicaton: screenshot • All input are propagated as asynchronous events, which can be either polled or handled by callbacks on the application. • There’s 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.

10. The PDA is a cluster node • Glass is used underneath • To Glass, the PDA is just another node

11. Application Java Java Virtual Machine JNI Glass Operational System (Linux, Windows CE, Windows) PDA software layers

12. Celestia Application

13. Cathedral Application

14. 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 • It’s 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