There have been numerous attempts to create open Metaverses, either from scratch or through joining up smaller or separate worlds. There is little agreement on what it even means to be a Metaverse. Most 3D virtual worlds have the basic model of avatars, regions and items, syncing their changes across instances. Mnemonically: People, Places and Property. The Object Network has a vision of The Metaverse that also includes the following features (see also the design goals on the front page):
The Object Network is designed to meet these requirements through the power of the link. Can your system meet the Missing Link Challenge...?
I build a nice garden on my mobile. You also build a nice garden on yours. Working over the wifi we set appropriate permissions and can now join our gardens together into a continuous landscape. I see that your garden has a tree in it that I like, so I walk across and pull it out, then walk back to my own garden and plant it there instead!
It's still your tree, hosted on your own device, so if you wanted revenge you could simply turn it into a nasty prickly bush. If you switch off your device, visitors to my garden can still see your tree.
Note that copying isn't necessarily what is needed in these situations. If something is dynamic, such as a shared document or an external input such as a thermometer showing the outside temperature, then you usually don't just want a copy that loses the source of those updates, you want a clone of the original, but placed somewhere more convenient for you, perhaps. However, if something is static, which most things in virtual worlds are, the copying is redundant and uses up resources. Copying would only be useful if you either want to go on to make your own changes to it, or it comes with behaviours such as a door that opens when you touch its handle: you don't want someone opening the original door to cause all clones or copies of it to suddenly swing open all over the place!
Consider three broad categories of popular, mainstream Virtual World approach:
These games and worlds are generally centralised, closed, walled garden, proprietary and incompatible, with isolated regions, rooms or worlds even within them. It's jarring and clunky to move or "teleport" between worlds, regions or rooms, and the attempts to allow teleporting between each of these closed worlds are even worse if they exist at all. It seems likely to be quite a challenge to transfer property between the isolated regions and worlds.
The real competitors to the Object Network Metaverse are more like the following:
The blockchain-based worlds and Hubs and Jel are web-based, which comes with a set of challenges because the existing web model stretches beyond its comfort zone when implementing virtual worlds:
Looking at the above requirements list: web-based worlds are somewhat decentralised, but the web is almost never operated peer-to-peer with a web server on your laptop or phone; P2P needs more custom websocket code. In web-based worlds, you can usually link rooms or regions together via their URLs. However, that doesn't make them seamless or contiguous; you have to do a heavy reload to the new region's entire page rather than seamlessly walking. Web-based worlds can implement transferrable identity through OAuth, WebIDs, etc, which are quite centralised. Property should be transferrable between worlds simply through their URLs, carried on your avatar then placed anywhere that offers permission to do so. But it doesn't seem the above systems offer this.
The blockchain-based worlds do have an element of decentralisation and ownership by normal people, and you can walk between regions owned by different people around the world. However, their land is designed to be owned centrally overall and parcels issued centrally, and is artificially scarce in order to generate income and for speculation by landowners on the underlying cryptocurrency. These systems have separate layers for static land allocation and asset storage and dynamic functions such as presence (avatar pose, chat) and multiplayer world state. The multiplayer services allow people to make changes to or interact with the assets in-world and for item changes to be seen by everyone. The servers for these dynamic functions may also be centralised.
Decentraland appears to only have Places and People, not Property, other than wearables for People. So you won't be able to pick up an item in one region and drop it in another. See also User Inventory and Sync Scene State in their docs, where they offer some sideways solutions to shared state of in-world objects. Cryptovoxels lets you change assets in-world, either permanently back to the asset server or, in a similar sideways bolt-on to Decentraland, temporarily in a centralised service called, confusingly, the Grid. The Grid lets others see the changes (e.g., doors opening), but it will revert to the static state when the region has nobody in it, and new arrivals see the static state, not the latest state. Each of these sideways world-state solutions are per-region, so it would be even harder to arrange transfer of any asset or item between separately-owned regions. Webaverse is early in development and has little to show, but they do promise in-world editing, an inventory and transferrable Property through NFTs, so that's one to watch.
Mozilla Hubs is an open source, web-based system that is very easy and pretty functional; it's possible to get started really quickly. It has a way to import and share media and their URLs through drag'n'drop. Jel builds on the Hubs experience, adding some idiosyncracies of its own, such as a toroidal endless world. Hubs and Jel are really focused on bringing the 2D world into 3D, useful for business meetings and so-on: a 3D version of Zoom and Docs.
NeosVR is very focused on high-end VR hardware and is proprietary to a large degree. Its architecture isn't fully available, but it apparently operates in a P2P mode with some centralised functions. It has isolated worlds with non-contiguous teleporting. It has accounts which are used for saving inventory to central servers and to manage friends. Identity and avatar appearance appear to work across worlds, but it's not clear, and seems unlikely, that you can carry anything and leave it behind, except by copying into and out of your inventory, which loses the connection to any unique original and adds to resource requirements overall.
OpenSimulator is quite an old system based on Second Life. You may download the Second Life or Firestorm client and connect to a service such as the OSGrid or Metropolis, which run the OpenSimulator servers. Each such server offering has its own accounts and 2D mapped fixed grid, which allows seamless walking between regions owned by different people, as long as permitted. Teleporting between regions on different grid services requires "HyperGrid" support, which is similar to URL-jumping in web-based systems. It seems you can carry stuff along on this journey, and pick up freebie objects to bring home. The HyperGrid tech is bolted on to the once-proprietary Second Life protocol so overall it's probably not going to be a pretty technology. It's almost there in terms of the challenge above, but it has a very heavy, clunky feel (for people brought up on Minecraft's super-slick experience!) and all of the associated websites have extremely dated UX.
So, in summary, proprietary and commercial offerings can't deliver the "3D Web" in the same way that they couldn't have delivered the 2D one. And the 2D web itself isn't quite up to transitioning to 3D without ugly bolt-ons.
So we do need to start again with an open technology stack for the 3D Web. We can keep many things from the web, such as URLs, cacheing and shared data types, but we need to transition from the "one-way client-server static document" model, to a "two-way peer-to-peer dynamic data" one.
Blockchain-based worlds, running in web browsers, are not just inheriting the issues there, but add additional issues around centralisation and artificial scarcity of the underlying currencies and disjoint, centralised servers for dynamic aspects.
NeosVR is a closed technology and has isolated worlds apparently without seamless natural property transition. OpenSimulator is aged and clunky, with ex-proprietary and bolted-on protocols.
Pictures and slides on the Object Network Metaverse
Many more broader and deeper articles and presentations
Let me know what you think! There's a contact email at the base of the page.
Duncan Cragg, 2021. Contact me