Distributed Interactive Simulation |
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Work List |
Discussion on current efforts, open issues and future work happens via the dis-java-vrml mailing list at dis-java-vrml@stl.nps.navy.mil. You must subscribe before you can post to the dis-java-vrml list - this policy prevents e-mail spamming. Mail traffic is documented in the hypermail archive at www.stl.nps.navy.mil/lists/dis-java-vrml/mailingList.html.
Goals and Expected Results | Status: Who What & When |
Current priority problems: |
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Freely available implementation of the DIS protocol using VRML and Java. | We are most of the way through the initial protocol data units (PDUs). The full set of software is available for download via the Software Distribution page. All of the source programs are fully documented via the Software Reference page. Additional contributions are welcome. |
What about the other Protocol Data Unit (PDU) types? | The IEEE DIS standard is a big standard to implement. We have implemented
several including Entity State, Fire, Detonation and Message PDUs.
Thus our implementation of the full DIS specification is incomplete.
Here are the status pages on
implemented PDUs
and
implemented records.
The DIS class library is documented and designed to be easily extensible so that other contributors might easily add the remaining PDUs. If you are implementing additional PDUs, please let us know (to avoid duplication of effort) and follow the Code Design and Coding Standards guidance. |
A set of recommended practices and example code for using DIS with VRML. | Basically, building this library and including example applications accomplishes the recommended practices task. When we get closer to a complete implementation, we intend to produce a "Recommended Practices for DIS-Java-VRML" proposal for the VRML Review Board (VRB). |
Utilities: AWT DIS viewers, data loggers and PDU playback, etc. | AWT PDU viewer
provided for Entity State PDU (Espdu).
AWT Espdu Sender can generate Espdu traffic easily easily. Students at George Mason University might be doing data loggers/playback routines... More work is needed to provide other utilities. |
Math and physics libraries | Basic quaternion math library provided by Kent Watsen. Still need geographic coordinate conversion routines, perhaps a tutorial too. Additional dynamics models for different vehicles are optional but can be added (full underwater vehicle hydrodynamics is a popular example around here). Some day (in the wonderful future) NPS will likely attempt to provide standard physics libraries that provide specific parameterized equations of motion for a variety of vehicle types. |
Examples updated, update readme & how-to files. | The Software Reference can always be improved. We do pay attention to suggestions (hint hint)! If you encounter something inscrutable, or can't find an answer you need, please tell us. |
Where are the bug lists? | We try to document bugs local to the problem, meaning that problem statements
(and guesses about how to fix them) are usually right in the source code
documentation. Thus we haven't built standalone bug lists.
Please look in the various Readme.txt files (available via the
example applications
page), in the
JavaDoc documentation for each class, or in source code comments.
Looking back in the mailing list hypertext archive will show previous dialog. We need to add a search engine - software suggestions are welcome. If www.vrml.org gets a search engine for all working groups, we might transfer the mail archive there. Got a bug? Please subscribe to the dis-java-vrml mailing list and report it to dis-java-vrml@stl.nps.navy.mil |
Browser combinations under test | Cosmo Player 2.0 & 2.1B
running under Netscape Communicator 4.05, WinNT/Win95
Intervista Worldview 2.1 Beta running under Internet Explorer 3.02, WinNT/Win95 Intervista Worldview 2.0 running under Netscape Navigator 3.01, WinNT/Win95
still no Java through the Script node, and thus unusable:
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How do changes in Netscape Communicator/Internet Explorer 4.0 affect the lack of multicast capabilities in prior browsers? What are the changes in the browser security models? Can we provide authentication capability using signed applets to permit native multicast access? | This is a major problem area. Currently we are working with Cosmo Player 2.0
and WorldView 2.1. There has been a lot of behind-the-scenes agony,
uh... unresolved work, which is occasionally summarized on the mail list.
ViewUDPTestApplet exercises the biggest bug: UDP packets throwing exceptions in Netscape. Currently NetworkMonitor hacks around it by rereading UDP datagram contents while inside the exception. |
Effective code contributions added to the dis-java-vrml archive. | Where are you people?!? A recent count showed 139 lurkers and 4 contributors.
No kidding.
We hope that getting dis-java-vrml examples to work with a single click - plus global MBone testing of demonstration applications - will be widely useful, eventually. |
Why won't multicast travel over a modem line? | We think this is a problem with the
Point-to-Point Protocol (PPP)
which is
Request for Comments (RFC) 1661
at
ftp://ftp.isi.edu/in-notes/rfc1661.txt.
More investigation is needed. Script
remoteBridge.bat
has worked for a few datagram PDUs, but the PPP modem link soon crashes.
We have worked around this problem by building a unicast UDP version of the MulticastRelayClient/MulticastRelayServer. The Examples page and Bridge directory contains relevant software efforts. |
Technical paper on DIS-Java-VRML design. | Don Brutzman and Don McGregor plan to do this someday. |
Recent and upcoming events:
| Demos are possible during each event.
We are starting with small-scale exercises and intend to eventually perform large-scale multicast application (LSMA) demonstrations. |
Available projects:
| "Your name here" to participate in any of these tasks? |
Specific fixes needed:
| "Your name here" for any of these? |
Create a public-domain C++ DIS library archive, for developers who want to freely bundle similar DIS functionality in other programs (such as browsers written in C++). | The
NPSNET
C++ code for DIS is available via the
dis-java-vrml distribution
page.
Any other public domain C++ DIS distributions can be publicly distributed via the dis-java-vrml site, if they are openly released under the terms of the GNU General Public License. |