1. Set-up

1. Install Java 8 -aka 1.8- (you can check your version with java -version)

   • Unix: sudo apt-get install openjdk-8-jre
   • OSX:
     • brew tap AdoptOpenJDK/openjdk
     • brew cask install adoptopenjdk8
     • If troubles, check: how to install Java on Mac OS
   • Windows: Java 8 for Windows

2. Clone repo and install grpc:

   • git clone https://github.com/real-itu/Evocraft-py
   • pip install grpcio

2. Starting the modded Minecraft server

1. From Evocraft-py folder, start the server with java -jar spongevanilla-1.12.2-7.3.0.jar
2. The first time you try to start the server a texfile eula.txt with be generated, you need to modify its last line to eula=true to accept the Minecraft EULA. Now running java -jar spongevanilla-1.12.2-7.3.0.jar will start the server
3. You should see a bunch of outputs including [... INFO]: Listening on 5001. This means it's working and the Minecraft server is ready for commands on port 5001.

3. Spawn blocks on the Minecraft server with Python

There are three methods at the core of the API: spawnBlocks spawns a set of different blocks, fillCube spawns a single type of block over a cubic volume and readCube which reads currently spawned blocks within a space.

If you aren't a seasoned Minecraft scholar, you can check information about different Minecraft blocks.

Here's example on how to spawn a flying machine with python (you'll need to have started the modded Minecraft server before):

import grpc

import minecraft_pb2_grpc
from minecraft_pb2 import *

channel = grpc.insecure_channel('localhost:5001')
client = minecraft_pb2_grpc.MinecraftServiceStub(channel)

client.fillCube(FillCubeRequest(  # Clear a 20x10x20 working area
    cube=Cube(
        min=Point(x=-10, y=4, z=-10),
        max=Point(x=10, y=14, z=10)
    ),
    type=AIR
))
client.spawnBlocks(Blocks(blocks=[  # Spawn a flying machine
    # Lower layer
    Block(position=Point(x=1, y=5, z=1), type=PISTON, orientation=NORTH),
    Block(position=Point(x=1, y=5, z=0), type=SLIME, orientation=NORTH),
    Block(position=Point(x=1, y=5, z=-1), type=STICKY_PISTON, orientation=SOUTH),
    Block(position=Point(x=1, y=5, z=-2), type=PISTON, orientation=NORTH),
    Block(position=Point(x=1, y=5, z=-4), type=SLIME, orientation=NORTH),
    # Upper layer
    Block(position=Point(x=1, y=6, z=0), type=REDSTONE_BLOCK, orientation=NORTH),
    Block(position=Point(x=1, y=6, z=-4), type=REDSTONE_BLOCK, orientation=NORTH),
    # Activate
    Block(position=Point(x=1, y=6, z=-1), type=QUARTZ_BLOCK, orientation=NORTH),
]))

To read the blocks present within a set of coordinates use readCube:

import grpc

import minecraft_pb2_grpc
from minecraft_pb2 import *

channel = grpc.insecure_channel('localhost:5001')
client = minecraft_pb2_grpc.MinecraftServiceStub(channel)

blocks = client.readCube(Cube(
         min=Point(x=0, y=0, z=0),
         max=Point(x=10, y=10, z=10)
))

print(blocks)

You can see the implemented Python methods at minecraft_pb2_grpc.py. For the general grpc definition please see minecraft-rpc.

If you'd like to interface with the server using other languages than Python, you can use the interface definition file you can generate clients for (almost) any programming language you like. See https://grpc.io/docs/languages/ and minecraft-rpc.

4. Rendering Minecraft

You can use the method client.readCube that allows to read which blocks are spawned, however, if you'd like to render Minecraft to see what your spawned creations look like or even interact with them, you'll need to buy and install Minecraft

1. Install and launch Minecraft
2. Create a compatible version:
   1. Installations
   2. New
   3. Give it a name
   4. Select version 1.12.2
   5. Create
3. Launch it:
   1. Play
   2. Multiplayer
   3. Direct Connect
   4. On Server Address write localhost
   5. Join Server

On the server command line, you can use /tp @p x y z to teleport yourself to position {x,y,z} in the world.

5. Useful commands that you can type in the running server console

• defaultgamemode creative to set the default mode to creative;
• setworldspawn x y z to set the default player spawn point;
• time set day to set time to day;
• gamerule doDaylightCycle false stop the day/night cycle;
• gamemode creative <player name> set creative mode for a specific player (sometimes the default isn't working);
• teleport <player name> x y z teleport a player to x,y,z coordinates.

Et voilà:

Research projects using the EvoCraft API

In this section we'll compile implementations of evolutionary algorithms using the API

• Interactive evolution: Evolve Minecraft entities interactively.
• Simple tower evolution in Python: Evolve tower that reach for a golden block in the sky.
• Evocraft 2021 winner: Novelty search and automated designer approaches to redstone circuit discovery.
• Meta-Diversity Search in Complex Systems, A Recipe for Artificial Open-Endedness
• Open-ended creation of hybrid creatures with Neural Cellular Automata

Citation

If you use the code for academic or commecial use, please cite the associated paper:

@inproceedings{grbic2021evocraft,
 title={EvoCraft: A new challenge for open-endedness},
 author={Grbic, Djordje and Palm, Rasmus Berg and Najarro, Elias and Glanois, Claire and Risi, Sebastian},
 booktitle={International Conference on the Applications of Evolutionary Computation (Part of EvoStar)},
 pages={325--340},
 year={2021},
 organization={Springer}
}