[Proposal] Add support for multi-agent environments

[pseudo-rnd-thoughts]

It would be nice to add gridworld based multi-agent environments.
These are could be used for reserach into RL safety, explainability, emergent communication, etc

If there is anyone who has already create MA environments or is interested in working on this problem then please respond

[ygrayson]

Check out this: #37

[pseudo-rnd-thoughts]

Wow, thanks for pointing that out.
As the project is Apache 2.0, we should be able to move the code to Minigrid to allow more users to use it.
I haven't looked at the code but we might want to shift the project to use PettingZoo rather than Gym/Gymnasium as it is multi-agent rather than single agent.

[ini]

Here's a fork with multi-agent support: https://github.com/ini/multigrid

It follows the RLlib MultiAgent / PettingZoo ParallelEnv API.

[pseudo-rnd-thoughts]

Amazing, thanks for doing that.
Could you be interested in merging this into minigrid itself?

[ini]

I'm not sure how simple that would be. While the external interface is supposed to be the same as minigrid, there are some significant changes under the hood for speed optimizations (i.e WorldObj and Grid are represented with numpy arrays, and the partial observation logic uses numba.)

Also, it only supports Python 3.9+.