We're all familiar with hypertext links on the Web. But what is a virtual world hyperlink?
In the hypergrid model, we consider the 2D map of the virtual world as the equivalent of a web page. As such, a VW hyperlink is simply a region on that map.
The default model of opensim-based virtual worlds already supports this concept of hyperlink, to some extent. When you teleport from one region to another via the map, chances are you are migrating your agent into a different opensim server. This migration is a glorified "agent transfer" that also exists, in rudimentary form, on the web when hypertext links are followed. The default model, however, imposes two very strong constraints on these hyperlinks:
- The entire map of regions is controlled by a central service known as the grid service, whose job is to provide a uniform view of the world to all of its regions.
- The only agents that can be transferred are those pertaining to users known to another central service, the user service; if the incoming user is not on that service's database, the agent transfer doesn't go through.
The hypergrid simply removes these two constraints.
First, it allows individual opensim instances to add "neighbors" to their local map, shifting the control of the map down from the grid server to individual opensim instances (although hyperlinks can also be served by grid servers if grid admins so wish). In doing so, the world becomes a lot more interesting and varied. The map that you see in one opensim instance may be completely different from the map that you see after you teleport via an hyperlink. As an opensim administrator, you are free to define what other opensims you want to see on your map.
Second, it allows the transfer of agents pertaining to foreigner users, i.e. users who are registered elsewhere. Instead of assuming one central user service, the hypergrid assumes an arbitrarily large number of such services distributed all over the world. As such, when agents are transferred among hypergrided opensims, a lot more information is passed about the corresponding user. That information includes the collection of servers that the transferring user needs.
The following are some usage scenarios. There isn't a clear separation between these scenarios, there's a large overlap between them. This is also not an exhaustive list. The purpose of these descriptions is to give you some starting ideas for how to use the hypergrid in practice. Please feel free to add other interesting scenarios to this list.
This first scenario pertains to standalone opensims. Normally, standalones are completely disconnected from the internet. However, when run in hypergrid mode, standalones become network-able. As such, you can run your own world in your own computer, and link your world to whoever you want. For example, you can link to your friends' hypergrided opensims and to hypergrid gateways in open grids such as OSGrid.
The great thing about this scenario is that all of your assets are stored on your computer, and not on somebody else's server. You can back them up using ordinary backend tools. The not so great thing about this scenario is that all of your assets are stored on your computer! If your disk goes berserk, you loose them. (so make sure you make external backups regularly)
This second scenario is about communities, broadly construed. The idea here is that a group of people come together to support a small community grid, i.e. a common world where shared activities take place. But at the same time, the members of the community maintain their own standalone worlds. The standalones link to the community grid, and the community grid may link back to the individual members' worlds and other places of interest.
The members' identities are probably the identities they have on their standalones, and their assets are also probably stored there. The assets present in the community regions, however, are stored on the grid asset server.
Grid Public Regions
Walled-gardens are here to stay, and they serve many useful purposes. There is a hybrid mode for the hypergrid that some walled-garden grid operators may be interested in supporting. In this hybrid mode, most opensim instances on the grid run in normal, wall-garden mode, so no foreign visitors are allowed there - technically it is impossible to reach them. However, a few opensim instances on that grid can run in hypergrid mode, so that foreign visitors are allowed. This way, there is a gateway for grid-local users and arbitrary visitors to meet. This is also a good strategy for attracting new users to the grid, since random users are able to visit those gateway regions without having to sign up for an account upfront.
This hybrid mode is very similar to what happens on the web. For example, anyone can visit Facebook's public pages without having to sign up for a Facebook account. However, only Facebook users can go further inside.
The normal version of OpenSimulator enforces a common map for all the regions on a grid. The hypergrid removes that constraint. As such, it becomes easy to design VW games where the world looks different depending of where the player is.