Distributed Virtual Environments and VRML: an Event-based Architecture

1. Distributed Virtual Environments and VRML: an Event-based Architecture HP Labs BristolFilton Road, Bristol BS12 6QZ, UK http://keryxsoft.hpl.hp.com/ Rycharde Hawkes rjh@hplb.hpl.hp.com Mike Wray mjw@hplb.hpl.hp.com

2. Overview • Keryx Notification System • Distributed Virtual Environments • VRML • Living Worlds • Applications • Summary

3. Reaction Keryx Notification System • Publication • Anyone can declare an intention to send notifications • Notifications are undirected • Subscription • Anyone can register an intention to receive notifications • Notifications filtered by a content template Reaction • Notifications • Self-describing packages of information about something that has happened (an event) • Propagation • Supporting servers send notifications to end-users • Propagate only if interest exists

4. Self-describing Data Representation { system { message-id 97 } type ( emit ) content { type ( mutech zone ) sender "15.144.30.194/123/1" id "zone0" op ( object update ) oid "15.144.30.194/123/47” update { pos ( 1.01 2.23 1.57 ) ori ( 0 1 0 1.237 ) } }} • http://keryxsoft.hpl.hp.com/documents/sdr/draft-low-sdr-00.txt

5. WWW Browser Web Server Event Distributor Video Camera Active Badge ‘Smart Seat’ Keryx Notification System Internet Events Events Events Events WWW Site Watch Events Open Set of Devices Events Events Enterprise Telephony Electronic Mail PBX

6. Distributed Virtual Environments • What are they? • Shared, virtual worlds on the Internet. • Why distribute them? • Too large to manage in one place. • Enables multiple participants. • Decentralises ownership. • What does a DVE need? • Scalability. • Interoperability. • Extensibility. • Openness. • Consistency. • Persistence. • Interpersonal communications.

7. Rych Mike Managing DVEs EventDistributor Zone A Zone B ZoneServer Zone C Zone D

8. WWW Browser JavaApplets,etc. VRML Browser EAI VRML World Java Scripts External Services, e.g. KNS Network VRML & Living Worlds • VRML • “3D on the Internet”. • Single user. • Living Worlds • Standard multi-user extensions to VRML. • Java • VRML browser and WWW browser share same Virtual Machine. • Embeddable in VRML. • Applets can use External Authoring Interface. • Either can interface to other services.

9. Living Worlds • VRML events intercepted and injected by Living Worlds nodes. • Multi-user technology (MUtech) is vendor-specific. VRML WorldLiving Worlds VRML WorldLiving Worlds MUtech MUtech KNS KNS Web of ZoneServers Network Network Client 1 Client n

10. Living Worlds Client A Client B Client C Pilot Drone 1 Drone 2 Zone Client Zone Client Zone Client EventDistributor ZoneServer MUtech

11. CubeWorld

12. Virtual Helsinki • http://www.helsinkiarena2000.fi/

13. Virtual Helsinki Models created by Arcussoft, Finland.

14. 3D Tele-Conferencing HRTF

15. Summary • Keryx Notification System features: • Publish-subscribe paradigm. • Publishers do not (need to) know who their subscribers are. • Filtering performed in the Event Distributors. • Language neutral. • General DVE Support • Implemented on KNS. • Basic services such as zoning and state updates. • Living Worlds MUtech • Higher level adds advanced services, e.g. data consistency. • What about… • Scalability, Interoperability, Extensibility, Openness, Consistency, Persistence, Interpersonal communications.