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Re: HyperGrids -- connecting virtual worlds for OpenSim and web arch

From: Cristina Videira Lopes <lopes@ics.uci.edu>
Date: Mon, 1 Mar 2010 15:43:33 -0800
Message-Id: <0106F3A4-30E4-4C7C-A0B5-BA068D2269C9@ics.uci.edu>
To: www-tag@w3.org

OpenSim is a 3D simulator which accesses resource services via HTTP,  
and which can be accessed via HTTP. Resource services include  
identity, assets, inventory, social network, instant messaging, etc.  
OpenSim worlds can run as walled-gardens (a-la Second Life, Wow, etc)  
or as a web of interconnected independently-operated worlds via the  
Hypergrid, like the Web. In the Hypergrid, unlike on the Web, identity  
is maintained throughout the user's session as the user goes from one  
organization's world to the next, in a seamless and relatively secure  
manner (*).

So, to answer the question: yes; for example, here's the address of my  
own world: ucigrid01.nacs.uci.edu:9001. I didn't include the protocol  
handler, because that can vary and it will have different results. If  
you type http://ucigrid01.nacs.uci.edu:9001 on your web browser,  
you'll get the standard "Oops" page from my world, meaning that it's  
alive, but it's not serving any interesting html content. There's a  
bunch more URIs that are served from it for doing specific functions.  
For example, agent transfers are done via HTTP POST operations.

If you click on this other link secondlife://ucigrid01.nacs.uci.edu: 
9001, it will try to launch the SL viewer, but you won't be able to  
visit because it will try to log you into Second Life. (SL doesn't  
support the Hypergrid or any other interop protocol yet, it's still a  
walled garden)

Once you are successfully logged in to an Hypergrided OpenSim world  
(needs some configuration plumbing on the viewer), you can then  
navigate seamlessly in the Hypergrid via handlers that have the secondlife:// 
  form, but will probably have some other name in the future.

Work in progress, still a lot to do, but I hope you'll get the idea of  
where this is going: complete compatibility with the 2D Web. But  
equally important are (1) architectures for supporting portable  
identity among different worlds; (2) architectures for supporting fast  
state updates between a world and the clients; and (3) server-side  
architectures for performance optimization on serving scenes to clients.

WRT (1) anonymity will be supported, but identity is critical in VWs;  
enough people within the OpenSim community believe that it's time to  
fix this problem once and for all. Some ppl are looking at OAuth,  
others (like me) are doing cleanroom design. Hopefully all this  
experimentation will converge. I strongly believe that whatever we end  
up with for a web of VWs can be used also for portable identity in the  
2D web (and vice-versa, if it gets solved there first in a suitable  
manner for VWs, i.e. secure seamless transfers).

WRT (2), these systems have much higher demands on state updates than  
your regular web application; you move your avatar, and that needs to  
be seen almost instantaneously in all other connected clients, etc.  
There's potentially a large stream of these events that need to be  
sent to many clients all the time.

WRT (3) there's a whole world of dynamic load balancing waiting to be  
explored. Even though proprietary systems like Wow are doing this  
reasonably well, we haven't even started to scratch the surface for  
generalizing the needs and solutions.

There is work going on in the IETF championed by Linden Lab and IBM  
for VW interoperability. Linden Lab hasn't really done much on  
interoperability in practice, other than an incomplete prototype of  
half of a protocol for passing agents between SecondLife and OpenSim  
(but not the other way around, and not preserving access to the user's  
belongings). So that work at the IETF is more of a "standardize first,  
implement later" kind of approach, whereas the Hypergrid is a  
"implement first, standardize later". Assuming that we have the same  
system in mind, that is, a truly decentralized web of VWs, then the  
efforts at the IETF will converge with what's going on in OpenSim.

Is there any real interest from people in the W3C about this topic? We  
really want 3D VWs to stay compatible with the 2D Web. This topic of  
3D VWs would be a natural extension of what the W3C has been working on.


(*) Once we established the basic mechanism for moving agents around,  
security was the main issue to address. I couldn't possibly make  
justice to this issue in this email message. Just this: we're now  
about to move beyond HG1.0, which was totally insecure, to HG1.5,  
which is reasonably secure.

From: Tim Berners-Lee <timbl@w3.org>
Date: Mon, 1 Mar 2010 10:25:13 -0500
Message-Id: <FC2FD404-93E7-4C4C-9E53-87469F2438FF@w3.org>
Cc: Christa Lopez <lopez@ics.ucs.edu>
To: TAG List <www-tag@w3.org>
Interesting to see what connections there should be between web  
architecture and the hypergrid. Does the hypergrid use URIs? Can I put  
one in a HTML page and link to a virtual world portal?  Can I link  
back the other way, putting an arbitrary URI in a link in a virtual  

"The Hypergrid: An Architecture for a New Web: OpenSim is chartering  
territory in making Virtual Worlds interoperable with each other and  
with the Web. At the heart of it there is the Hypergrid, an emerging  
architecture that allows the seamless transfer of users' agents  
between grids operated by different entities. While the Hypergrid is  
coming to life in the context of OpenSim-based 3D Virtual Worlds, its  
foundations shed a new light into what the Web could be."
-- http://metaverse.stanford.edu/agenda/crista-lopes/crista-lopes


See also http://www.hypergridbusiness.com/2009/05/hypergrid-101-why-its-good-for-business/ 

Is anyone on the TAG following the connections with OpenSim?

Tim BL
Received on Tuesday, 2 March 2010 12:59:26 UTC

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