[Animats]

As I mentioned previously, there's not much written about this. Which is probably why existing metaverse projects are so awful. It's mostly taking Unity or Unreal Engine, which are intended for use with carefully pre-built content, and somehow trying to make a large dynamic virtual world from those parts. The duct tape is troublesome.

The primary technical designer of Second Life did a very good job. Then he had a disagreement with management and was fired. So he went to Facebook, developed their mobile client, became a Facebook VP, made lots of money, and was semi-retired for a while.

Scaling to a big world is really hard. Big has two dimensions - area and density. The Second Life architecture scales well in area but not in population density. More than 20-30 users in a region will choke it. More are possible if most users sit down and doesn't move, because sitters are not getting physical simulation. So audience-type events work.

Improbable was working on large crowds, but their solution is really expensive to run. Which is why they just do demos of Otherside for a few hours at a time every few months. Also, they use very simple avatars and do not, as yet, support vehicles. Took them over US$500 million to get to that point. They have dynamic regions - more people, divide the world into smaller chunks. That introduces a whole range of new problems. What if I have 20 people on my boat, and a region boundary moves under the boat while I'm crossing it? Stuff like that. Fixed region crossings involving multiple avatars and vehicles are troublesome in Second Life. People do try bus tours, but sometimes an avatar gets Left Behind at a region crossing. Linden Lab's devs have been trying to fix that for at least 8 years, without success. It's a tough problem in real time distributed system design.