Don Brutzman Naval Postgraduate School VRML and large-scale networking VRML Consortium Summit 7-8 NOV 97

Presentation overview This is my trimmed-down presentation on “VRML + Java + Networking” New points relevant to our summit are highlighted in green throughout Summary conclusions don’t “fix” VRML 97, it works large-scale virtual environments now possible network research/experimentation in progress

VRML Overview2 Large-scale internetworked 3D worlds are now possible Scaling up is both technical challenge and “people” challenge VRML is what we’ve been waiting for! Stable and compliant browsers are still biggest need - BUT recent release of CosmoPlayer 2 appears to fix that. Thank you, thank you, thank you!

VRML Overview3 Dynamic 3D scene description language with behaviors andanimation Rich set of graphics primitives gives common-denominator file format Well documented, ISO standard 20 year history of fracture and incompatibility in 3D graphics means we have every reason to fail. We can continue to defy those odds.

VRML Overview4 Web-capable similar to HTML: authors can insert/add objects to scene (Inline node) or replace entire scene (Anchor node) Interpolator animation and interaction Script nodes for Java and JavaScript Any kind of animation is possible First law of engineering: if it ain’t broke, don’t fix it

VRML Overview5 Open technology, developed by working group, ISO standardization VRML Repository OUT OF DATE VRML Consortium page SUCKS (long after a great setup by Rikk Carey) how about volunteers for web page? Working groups: losing juice?

Java Numerous desirable attributes for the LSVE application domain cross-platform, portable code recompilation not required network support VRML compatibility minor problems exist, can work around serious programming, examples help

Integrating Java + VRML 1 Class libraries specified for Java-VRML interface Script nodes encapsulate Java objects embeddable in the VRML scene ROUTEs link Java object fields/eventIns/eventOuts to 3D node fields it works

Integrating Java + VRML 2 Java objects can query (and interact with) browser as well as Web createVRMLFromString method enables Java objects to generate arbitrary VRML geometry a good fit

Integrating Java + VRML 3 See Annex C of VRML Specification for Java Script Authoring Interface (JSAI) External Authoring Interface (EAI) is draft work in progress which provides alternate Java-VRML-browser methodology Cosmo Player still has me so pissed off ¤ now has me so happy!!

General entity solution VRML Java renderingcomputation data sharing network Simple is Good!

Four key network components for LSVEs rationale for vrtp Light-weight interactions Short state/event messages via multicast Network pointers URLs to information resources Heavy-weight objects reliable client-server response Real-time streams - audio, video etc.

IEEE standard DIS protocol Large-scale multicast applications = Web Truly many-many communications Single entity bandwidth ranges from ,000 bps (bits per second) Latency & jitter compensated by timestamps & dead reckoning Example behavior/interaction protocol

DIS-Java-VRML Networking is the key hardware bottleneck, not 3D graphics rendering We think we can create virtual worlds open standards portable and scalable physics-based easy as building a web page

Java used for DIS library Can be used to animate VRML scenes via Script nodes Multicast capable (using JDK 1.1) Available: Netscape, Internet Explorer Portability across platforms enables scaling up to many users Initial performance is adequate (just-in-time Java gets ~80% C++ speed)

DIS-Java-VRML Data Flow intended message: it’s pretty simple

Goals: DIS-Java-VRML WG Complete freely available Java/C++ implementations of DIS protocol Easily stolen examples Produce recommended practices for mapping between DIS & VRML Utilities: record/playback, viewers etc. Math libraries and physics libraries

DIS-Java-VRML WG admin following the usual keys to success (which not all working groups have done) Open membership Meeting 21 November Archived mail list VRML Consortium

DIS Testing Build testbed lab at NPS 5-10 Linux boxes, masters student Round-the-clock exercises statistics, toolset development Low bandwidth going global on MBone Emphasis on end-user results Other sites welcome to collaborate slowww but steady progress

Test results crucial Determine pertinent parameters and corresponding values/distributions Large-Scale Multicast Applications (LSMA) IETF working group requirements IRTF Reliable Multicast RG Walk-before-run exercise complexity Build awareness what LSMAs look like

Internet-wide VRML animation Putting physically realistic entities (meaning real physics, F=ma) all interacting together on a live 3D Web

Dial-a-behavior protocol We are building a DIS-like data protocol, modifiable on-the-fly, that will allow rapid development of network communications tuned for applications large-scale multicast Public domain software written in Java Virtual Reality Modeling Language (VRML) compatible and scalable

Why dial-a-behavior protocol DIS entity state protocols hard to modify due to hard-coding, slow standards process Entity interaction protocols are a crucial network capability that need better testing Formal grammars and agents can provide a rapid modify/test/revise methodology Support testing and experimental results!

Protocol Definition Interface Grammar parser builds replacement protocol manager Multiplaye r networked Applicatio n Data Units AOIM - Area of Interest Managers Shared 3D VRML Worlds protocol-redefinition architecture driven by application needs

large-scale virtual environments LSVEs are now possible interactive 3D graphics using VRML fully internetworked (need a vrtp) extendible in every direction scales with the World Wide Web that means as easy as building a home page details details:

multicast networking crucial many-many communications, blah blah still pretty complicated, slowly improving filter packets at network interface card Global MBone “works,” also built in IPv6 partition network traffic (Macedonia) spatial, temporal, functional, your choice exploiting reality to better use network experimentation & testing are essential

use client/server or peer-peer? troublesome cul de sac: many conversations always seem to end up here must we choose only one? client/server: browsers, http, object request peer-peer: DIS PDU, other MBone streams realization: networking is not bipolar, rather a spectrum of functionality. Use all of it well.

why not use the full spectrum? client server peer http web browser multi-user worlds audio video DIS behaviors

examples in midspectrum client server peer http web browser multi-user worlds audio video DIS behaviors “reliable” multicast group-cached http servers (NCSA)

what does desktop look like? client looking at someone else’s world server showing others your world peer scalable many-many behavior interactions “everything just works”

what else is on desktop? client looking at someone else’s world server showing others your world peer scalable many-many behavior interactions “everything just works” means that network monitor capabilities are needed nobody! does this yet (even net gods)

so where does virtual reality transfer protocol (vrtp) live? HTML VRML 2.0 http vrtp

vrtp IS NOT... possible using just http yet another transport protocol a competitor to existing protocols a step in an untested direction about adding complexity hard for users to understand a push to change VRML, just support it

vrtp IS... a framework for combining essential best- of-breed protocols a combination of existing software a way to give user scenes easy access to a full spectrum of network capabilities URL extensions: client/server/multicast easy to use all about simplification & streamlining intended to best support networked VRML

VRML Symposia in Monterey VRML 97 Symposium 500 attendees (sellout) VRML 98 Symposium February Mon-Thurs breakeven 400, cap 900 ece.uwaterloo.ca/vrml98 sponsored by ACM SIGGRAPH and SIGCOMM in cooperation with VRMLC

VRML 98 February Monterey Monday & Tuesday Tutorials and working groups SGI Cosmo dinner at Aquarium Wednesday & Thursday 17 papers (44 submissions) 4 panels, to be determined Exhibitor booths (not World Movers...) Design show, Demo SIG Sponsorships available Add a day for VRMLC + web designers??

Contact Don Brutzman Code UW/Br, Naval Postgraduate School Monterey California USA voice fax