[X3D-Public] XMPP or not XMPP

Sven-Erik Tiberg Sven-Erik.Tiberg at ltu.se
Fri Nov 19 05:57:33 PST 2010


Thank you all for your advises.
We have just started up our QSIM motionbase 6 D.O.F. simulator (http://wbsp.arb.ltu.se/Motionbase/motionbase-ltu-applications/Labb-motionbase-f.JPG/view), two ejabberd servers and are now testing python and C-libs for XMPP interfaces.
Our first approach are to:
Connect CarSim RT/DS with QSIM Motionbase over XMPP packages.
Later make a Maya/Python VR Motionbase and connect it to the "XMPP confereration". 

This is a nice test for the XMPP package bandwidt and to suggest a state naming cheme.

Wouldn't be that hard to swap from Maya / Phython to X3D Browser / JS in the future nock nock.

Will let you know how this will work / not work.


-----Original Message-----
From: x3d-public-bounces at web3d.org [mailto:x3d-public-bounces at web3d.org] On Behalf Of Alan Hudson
Sent: den 7 september 2010 18:26
To: x3d-public at web3d.org
Subject: Re: [X3D-Public] XMPP or not XMPP

On 8/31/2010 5:47 PM, Tony Parisi wrote:
> Hi Sven-Erik,
> I think you can do it. I was considering trying it as an alternate to 
> our SWMP protocol at Vivaty. But I didn't get around to experimenting 
> with it before um everything went blooey over there.
> I would be most concerned with response times for MU messages. XMPP 
> was primarily designed to transport chat text. (I know it's more 
> general than that but I'm talking about in a practical sense). Then 
> again, networks keep getting faster so maybe response time is no longer an issue.
> There's also message size to worry about-- I am not sure what those 
> limits are in XMPP, and you probably don't want to transfer LARGE 
> messages for updates to scene graph state anyway. i.e. don't push 
> IndexedFaceSets around in this fashion ;->
> So I say go for it. At least build a prototype, it will be worth the effort.

response time for me was pretty good up to about 50K packet size.  When I tried to push scenes across it got too laggy.  For position/rotation updates its fine.  I seem to remember having about 50 clients in a room without trouble.

Using short form xml is best, ie something like this

<ap id="123456788" p="1 2 3" r="0 1 1 1.567" />

ie keep all the elements/attributes to 1-2 chars.

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