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Monday, August 11, 2008

A Bridge between Virtual Worlds

Continued from page 1

By Brian White

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To use the beta program, a participant starts an application called a viewer, the best example being the Second Life client. The viewer renders the virtual world and provides the controls for the avatar. Just like using a Web browser to log in to a website, the viewer is where a log-in request is initiated.

The log-in request is sent to the agent service, which stores things like the avatar's profile, password, and current location. As part of the beta, Linden Lab has implemented a proprietary version of the agent service running on a test grid. The avatar service now contacts the region service for the right placement of the avatar in the virtual world.

The region service is basically the Web server of virtual worlds. It is responsible for simulating a piece of the virtual landscape and providing a shared perspective to all avatars occupying the same virtual space. A collection of regions is called a grid. Linden Lab has proprietary code running all the Second Life regions. The OpenSim project provides source code that, when built, allows anyone to run his or her own region service.

From that point on, there is a three-way communication between viewer, agent service, and region service to provide the user's in-world experience. When the user wants to move to another region, he issues a teleport command in the viewer, and the same process happens. But in this case, the user is not required to log in again, even if the destination region is running on a non-Linden Lab server.

Last fall, Linden Lab formed the Architecture Working Group (AWG), which is the driving force behind the Open Grid Protocol--the architectural definition of interoperability. The team decided that the first step was to focus on the areas of log in and teleport. "We started with authentication information and being able to seamlessly pass the log-in credentials between two grids run by different companies," says Levine. "Many people ask me, 'Why did you start there?' Well, you can't do all the rest until you get logged in."

Miller says that in the next 18 months, a user can expect to see a lot of activity in the area of content movement. "How do I move content that is mine, purchased or created, between worlds safely and securely? The AWG has a lot of great thoughts on how this could work," he says.

Brian White writes a virtual world blog, Virtual White: An Exploration of Virtual Worlds.


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Comments

  • And What About IP?
    Prokofy on 08/11/2008 at 1:37 AM
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    Typically, your coverage has left out the problems of copyright and intellectual property when establishing interoperability between grids. As we all know, if you can see it on the viewer, you can copy it -- the reverse-engineered simulator coders have basically abandoned the notion of trying to implement copyright protections mechanically -- as they are now found in Second Life with a copy/mod/transfer regime built into the object menus. They belong to a school of thought that says this is futile, although of course big companies like Apple do not practice this copyleftism. It's a legitimate debate even among coders themselves as to the extent you can use obfuscation or encryption in these worlds, and the debate is not over merely because one school of thought announces that it is. The most popular -- and populated -- virtual worlds are "walled gardens" -- and that's how they secure themselves not only against copyright theft but against griefing. Second Life has the unique feature of user-generated content but its makers aren't interested in preserving its proprietary nature, unlike Google with Lively or IMVU or Habbo Hotel or There or any number of worlds, whether 3-d browser chat rooms or more elaborate contiguous spaces. None of those hugely populated MMORPGs and virtual worlds are actively seeking interoperability; it's not a necessity or goal but a distraction.

    For the purposes of SL, this issue can't be viewed merely from the consumer's perspective of "being able to take my stuff with me," which is how Joe Miller seems to frame it, but simply must be viewed from the perspective of the creator. How will his rights be preserved? There is a huge debate about this that you haven't reflected here by presenting these events as if they have some huge public support. They don't. It's not a public demand from most users; it is a small group of people around IBM and LL who have their own agenda.

    It's also quite overstating to describe the other grids as "worlds". They have very bare-boned features. OpenSim goes to great lengths to explain in fact that they are *not* a world but only a platform to generate worlds.

    Finally, this perceived annoyance of having too many avatars because there are so many worlds is also a bit of a geek affectation. Most people don't expect that their WoW avatar has to have the same name and log-on as their SL avatar; they can handle it.

    http://secondthoughts.typepad.com/second_thoughts/2008/08/zhas-at-it-agai.html

    http://secondthoughts.typepad.com/second_thoughts/2008/07/if-you-can-see.html
    Rate this comment: 12345
    • Re: And What About IP?
      Saijanai on 08/13/2008 at 6:10 AM
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      1
      I can only urge people to read the interoperability chat logs of the Second Life Architecture Working Group, especially those from the past few months, in order to get a sense of the concern that AWG members have about Intellectual Property. Consider, for example, the AWG meeting about inter-grid IP protection that took place on 10 June just after the first inter-grid teleport demo:

      https://wiki.secondlife.com/wiki/User:Zero_Linden/Office_Hours/2008_June_10

      not to mention the discussion on "Trust Domains" which took place this past Tuesday:

      https://wiki.secondlife.com/wiki/AW_Groupies/Chat_Logs/AWGroupies-2008-08-12

      The technical requirements to implement Intellectual Properties solutions of various kinds are relatively straightforward, requiring only a few man-months or man-years of work. However, the work to map out the boundaries of the problem from a social, economic and legal perspective is ongoing and has taken up hundreds of hours of discussion between many, many people and after all that we are still working to gain a sense of the possible range of end-user requirements that will need to be supported in a virtual worlds metaverse.

      Anyone interested in finding out  how wide-ranging these conversations have been, should consult these links to the many scores of chat logs and other web pages that discuss these issues in great detail:


      https://wiki.secondlife.com/wiki/AW_Groupies#Architecture_Working_Group_meetings

      Rate this comment: 12345
  • great minds think alike and fools never differ
    phoenix on 08/11/2008 at 10:59 AM
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    All debate, except for intentional slagging, is healthy if it helps to define the boundries, or social paramters, of a particular group. This process allows a loose aggregation of ideas, regardless of how technically refined they may be, to set the guidelines of acceptable behaviour. A sort of unwritten constitution starts to evolve until such time as the dynamics of said group demand a legal framework be put in place so that everyone has an equal opportunity to participate. I don't see the realm of virtual worlds being any different than that of real ones, as the interaction between the different competing factions gets played out in a common area.
    Rate this comment: 12345
  • Trust Management in Virtual Worlds
    Ugotrade on 08/12/2008 at 10:21 AM
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    1
    Now that the OGP teleport tests are well underway "the real meat is on the table": inventory and permissions and economy.  I have some interesting comments from Zero Linden (lead on AWG for LL) on the road map for this here.  http://www.ugotrade.com/2008/07/31/the-open-grid-beta-the-first-step-to-interoperable-virtual-worlds/

    Also Avi Bar-Zeev discusses trust/transactional security in this interview on the future of virtual worlds here http://www.ugotrade.com/2008/08/08/will-the-future-of-virtual-worlds-be-in-the-browser-interview-with-avi-bar-zeev/
    Rate this comment: 12345
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