Show HN: Pumpkin – A Modern Minecraft server written in Rust

Hello. I recently developed Pumpkin, Its a efficent and fast Minecraft server completely written in Rust from the ground up, Check it out :D

> What Pumpkin will not

> Be a drop-in replacement for vanilla or other servers

It seems to me that unless it's a drop-in replacement its not a Minecraft server? Akin to how say an Uno deck isn't a drop-in replacement for a Hearts deck but still both card games but not both Uno decks.

Or is it just meaning that Pumpkin (besides the network) do things differently than vanilla and so you might not be able to open a vanilla created world using Pumpkin?

Cool! Would be interesting to understand how to multithreading works? Is it just the "easy" parts or actual operations related to the world as well?

The common problem with Minecraft server implementations is that they are not bug-for-bug compatible, which will lead to certain techniques (especially redstone contraptions) breaking. The technical Minecraft community depends on many implementation details which not all servers support

In addition to the hundreds of blocks and mobs that would need to be implemented properly and rarely are, the lack of mod support is a killer.

The only "complete" reimplementation of Java Minecraft that I'm aware of is Bedrock.

Far from it. The versions lack a lot of parity and Bedrock is called "bugrock" by the community for a reason

I edited in scare quotes for "complete" to make that clearer, but I mean in terms of at least having matching blocks/mobs despite many differing details.

Minecraft has a lot of bugs or otherwise surprising behaviours that parts of the community have come to rely upon. This means that most non-vanilla minecraft servers aren't 100% drop in replacements. You have to make a decision what behaviours you want vs the performance and simplicity gains you will gain.

For example there there are tricks that allow you to delete bedrock blocks. Which then lets you either get onto the roof of the nether, or drop below the bottom of the world. Not all of these tricks will then work depending upon the specific minecraft server.

Another example is that in vanilla you can "bomb" people with experience orbs, the sheer number of orbs on the screen will grind their game to a halt since there are too many objects to track and render. Some minecraft servers work around this by grouping up experience orbs into a single bigger orb. That way you have fewer orbs on screen at once.

There are no bugs in Minecraft, only features that have yet to be fully documented.

Currently Pumpkin has not much multi-threading but we want to go all in. There is already a good structure for multi-threading, We want to make everything multi-threaded what benefits from it

One bug abuse that blew my mind recently is the ability to have wireless redstone in vanilla [1]. I fell deep into that rabbit hole after a previous post on here about Bad Apple in Minecraft [2].

[1] https://www.youtube.com/watch?v=FLynwXDnETI [2] https://news.ycombinator.com/item?id=41798369

A lot of the parity issues are due to Bedrock not reimplementing bugs from Java (quasi-connectivity aka "droppers are doors".)

IMO chuck generation is a great candidate for mutlithreading. Keeping it off the main thread would already be a huge improvement.