Show HN: Lyceum – An MMO game built with Zig and Erlang

[schonfinkel]

Hey HN, this is a small project myself and closer friends have been building on our free time (https://github.com/Dr-Nekoma/lyceum), it finally reached 0.1.0, we are open to feedback!

The original idea was to experiment with Zig + Raylib, eventually we wrote a small server in Erlang as well. We started by first interacting with Erlang via its C bindings, but this eventually led to some of us to prototyping our own tooling to better integrate Zig types with Erlang, we called such tool "zerl" as its avaliable here https://github.com/dont-rely-on-nulls/zerl.

Most of the developers are NixOS users, so the tooling heavily relies on Nix as well, including a Postgres running our devshell as well.

[Closi]

Pretty amazing effort, this looks like a great labour of love!

I can't give feedback on the code/technology, but on the writing on the lore section, I would try to simplify the writing. For instance the following:

> The reverberations of the trumpet stirred the knights from their deep repose, igniting a tumultuous awakening. With swords unsheathed and hearts ablaze, they clashed in a thunderous symphony of war, each seeking to claim dominance over the waking realm.

Feels too ornate (purple prose) and could be more directly put as:

> The trumpet’s call jolted the knights from their rest. Swords drawn and hearts alight, they clashed in a fierce battle, each striving for dominance.

I'm not an author or anything, but a little bit of copy writing could help - although this might just be me as it's probably a matter of personal taste!

[bitterblotter]

This definitely has a GPT smell, at no fault of the creator. Reminds me of a PR i reviewed about a simple security patch, where the description said "The following changes have been implemented to strengthen our role-based access policies and system security" - Like yeah, it's security patch. A small tweak to his prompt would probably do the trick

[skulk]

It's definitely a matter of taste. The first version has flavor, the second is flat. The first reminds me of the style of writing that got me hooked on MUDs.

[nonethewiser]

It's a style thing. Fantasy writing often does this deliberately.

I've thought about this before when I revisited fantasy after years of being in the CS domain which helped me abhor ornate writing. I definitely think there is such thing as TOO ornate but dead-simple language also feels bad. It feels wrong to just say its an exception with fantasy - simplicity is good because it conveys the same thing more clearly and with less effort. I would think that transcends all domains. Still not sure how I feel about this. I guess there is a baseline non-styled language that is all about communicating raw info and then there is style that can be applied to writing which makes it feel more natural in different domains.

Having said all this, I actually do like your example more.

[Kinrany]

The short version is better.

[wyldfire]

Maybe we could throw a "lurgid bee" in there somewhere?

[dgfitz]

The colorful version is better.

[mtlynch]

What's your experience been like with Nix?

How do you feel about devenv vs stock Nix? How are you getting devenv to work, as I don't see a devenv.nix file. I'm still a Nix beginner and would like to find ways of integrating it more into my development and improving my current techniques.[0]

[0] https://mtlynch.io/notes/nix-dev-environment/

[fluidwizard]

So, we've been using devenv for some time now and it's useful for describing a monorepo-like environment that zig-enjoyers can quickly code and test their changes on the latest version of the erlang server. Also, it's incredibly easy to also manage postgres from there.

It's great if you like local-first development experience.

[fluidwizard]

Regarding Zerl, my friend just presented about it in Functional Programming Sweden: https://www.youtube.com/watch?v=5Cuv0WnbZtk&t=795s.

[diath]

The BEAM is made with fault tolerance, scalability, and concurrency in mind at the cost of performance due to immutability and message passing approach among other things, which sounds like a terrible choice for a multiplayer video game that's anything more than a walking simulator. Erlang sounds like a good choice for auxiliary video game services, such as chat/social, guild management, auction house and so on, not so much for the game shard itself.

[DuLR10]

Given the current state of the game (the one we keep passing around between client and server), I don't think Erlang is a bottleneck in performance for us, and it won't be in the near future. Keep in mind this state is not that huge and it is yet not distributed, so it is totally possible that at some point Erlang will slow us down. I will keep your comment in mind, thank you!

Edit: currently with the game running at 60fps, there is no bottleneck from the server side. And we call it every 16ms! I should also mention that Erlang's choice has a learning purpose; we want to try to use the game as a way to learn more about OTP and the BEAM.

[toast0]

If it comes down to immutability and copies being a bottleneck, a solution is probably to move more of the core game state into native code (like with Zig), but fault tolerance, scalability, and concurrency seem like important things for a MMO.

Hot loading is pretty nice too.

[cmdrk]

it really depends on the game. people have been writing large-scale multiplayer games for over 25 years now, with MMOs sporting 2,000 player+ shards on significantly more primitive hardware. There is always this assertion that high-level languages of various flavors are too slow for games, but I suspect that today's hardware more than makes up for it for the right kind of game.

[racenis]

Do you think that you could use that Erlang feature where you can link up several server program instances running on separate physical servers?

Maybe you could simulate different parts of the game world on different physical servers.

I think this is something like what the Very Large MMOs do, but with Erlang it might be easier.

[DuLR10]

Sounds like an awesome idea for when we introduce the Server Browser! Thank you!

[mapcars]

Its always nice to see people experimenting with different technologies.

I'm curious about Erlang server, do you see any advantage or features that Erlang provides, compared to for example if the server was running in Python via multiple instances?

[DuLR10]

We haven't touched the distributed part of the game, but our understanding is that when that time comes, it will be easier to use the BEAM approach given that it was made for this purpose.

Given the experience so far, it seems that using Erlang was the correct choice, not only because of the above, but also because Erlang made the server implementation way easier than we thought.

[fluidwizard]

Also, Erlang makes it bizarrely simple to have a single process per user (and it's actually what we did for the demo).

[mysterydip]

I'm confused by the use of a 10,000 poly model for a tile instead of a flat (2 poly) square. I didn't even realize there were changes in its height from the animation on the page. Was it just to test things out and you plan to go to a full terrain later?

[DuLR10]

Former case. Just testing things out. We will for sure have to either learn Blender and this ecosystem or find someone with this skill set.

[canadiantim]

Seems cool, would love to see a couple more videos of gameplay, but otherwise looks really cool. I would definitely consider playing

[fluidwizard]

This version is actually a walking simulator XD, us trying to pull the crazy tooling together until it just works.

https://www.youtube.com/watch?v=ejYcWRERetM&t=2758s

Here's what the game consists rn

[subsaharancoder]

Did you happen to tinker with https://machengine.org/ it's a Zig game engine & graphics toolkit?

[fluidwizard]

Nope, but damn, this looks awesome!

[7bit]

I was clicking the source expecting to see what kind of game Lyceum is. There is no description about the game and no images of the game.

[DuLR10]

There are images and a gif in the repository: https://github.com/Dr-Nekoma/lyceum

You can also check it out a little demo: https://www.youtube.com/watch?v=ejYcWRERetM&t=2758s

[pmarreck]

Props for using Nix.

[lovegrenoble]

Will the game evolve further, and what is its future?

[DuLR10]

The main 3D part of the game is now on pause. We'll implement minigames (2D ones) leveraging all the current game's Zig and Erlang pieces. After getting that done, we may return to developing the main game.

[fluidwizard]

Yeah, so the game is kinda in a weird state where a library was born to make it work better, we are planning more features so it stops being a multiplayer walking simulator.

[newobj]

is Lyceum a reference to Ultima?

[lionkor]

> the client written in Zig (superchanged with raylib and Zerl).

What does "supercharged" mean here? I'd guess raylib simply does all the rendering and input handling, what is it "supercharging" here?

[meheleventyone]

It's just a superlative to give praise to the two libraries they are using to develop their game.

[xyzzy4747]

It just means they like raylib and Zerl and used them.