Setting up Minecraft to join our Virtual DevJam world

Welcome to Virtual DevJam 2020

DevJam is a fun unconference environment to get in contact with people contributing to OpenNMS. To get a similar fun environment in COVID-19 times we decided to try a very unconventional approach this year. Instead of a boring video conference where only one person can talk, we go to DevJam-Land in Minecraft. For voice chat, we use Mumble and the Mumblelink plugin in Minecraft with Positional Audio. This allows simulating the real world and you have to meet people to talk to them :slight_smile: To make this happen we have to install the Mumble Link plugin in Minecraft.

This wiki post can be freely edited and should provide guidance setting up Mumble, Minecraft and the Mumble Link plugin to get everything working.

You need Minecraft Java Edition and here some additional tools and plugins. To make it easier for you to get all the files you need we put them all in one spot which can be downloaded from here:

  • Minecraft Java Edition with a license with an account to log in
  • Mumble Client: Voice Chat software
  • Java 8: Required to run the Minecraft Forge installer which allows installing plugins and modifications
  • Minecraft Forge: Allows to run modifications in Minecraft
  • Mumblelink: A plugin in Minecraft which talks to Mumble Voice Chat to make the proximity chat feature happen
  • :headphones: work best to avoid echos. If you don’t use headphones it might be possible people hear themselves again.

1. Install Minecraft

You can go to the official Get Minecraft page or fetch the installer for your operating system from here.

  • Windows: MinecraftInstaller.msi
  • OSX: Minecraft.dmg
  • Linux Debian/Ubuntu: Minecraft.deb
  • Other: Minecraft.tar.gz


2. Install and configure Mumble Client

Mumble is our Voice Chat application. You can download it from the official site Mumble Site or from here.

  • Windows: mumble-1.3.2.winx64.msi
  • OSX: Mumble-1.3.2.dmg
  • Linux: Don’t use the AppImage (we don’t know how to add the required plugin). Use the apt source or the provided version from your distribution.

The installation procedure is pretty straight forward


When you start Mumble the first time you go through an assistant with three sections. Here are the important parts:

  • Pick the right Input/Audio video device and enable “Positional Audio”. The function “Use echo cancellation” works only on Windows/Linux and is not available on OSX :arrow_right: use :headphones:
  • You can select "High bandwidth audio for better voice quality
  • Add a server with the nickname you want to connect to with automatically created certificates. The server is

2.1. Audio Tuning for input / output devices

2.2. Creating a user certificate for identification and encryption

2.3. Adding a server and connecting to the server

2.4. Configure Link Plugin and Positional Audio

Click on the “Configure Mumble” icon (blue gear) and check the following settings:

3. Installing Java

Before we can install Minecraft Forge which runs the Mumble link plugin for us, we need a Java version installed. You can find it here or from the Oracle Java download page. It might be possible they require you to create an account to download it.
The provided OpenJDK 11 version ie. in Ubuntu does also fulfill the requirements.

4. Install Minecraft Forge

Start at least once Minecraft which intializes the directory structure and downloads the rest to be ready. Afterwards download the Minecraft Forge 1.15.2 Installer and run it with the Java Runtime Engine.

5. Install Mumblelink plugin

Download the Mumblelink plugin and copy it to the mods directory of your Minecraft installation. You have to create the directory mods.

  • Windows: %Appdata%.minecraft\mods\mumblelink-1.15.2-4.4.1.jar
  • Linux: ~/.minecraft/mods/mumblelink-1.15.2-4.4.1.jar
  • OSX: ~/Library/Application\ Support/minecraft/mods/mumblelink-1.15.2-4.4.1.jar

6. Install the MiniMap plugin (optional but recommended)

@Ganiman pointed out a helpful plugin which is called Xaero’s Minimap. It is a small map in the top left corner which helps you orienting in the world and find things easier. You just have to drop the JAR file in the mods folder the same way as you have installed the mumblelink plugin. I’ve added an Adware free download version here.

Path to the folder mods:

  • Windows: C:\Users<your-user>\AppData\Roaming.minecraft\mods
  • OSX: /Users//Library/Application\ Support/minecraft/mods

The plugin has some keybindings. You can find it when you go to “Game Menu” (Just hit ESC when you’ve connected to the server) -> “Controls” and scroll to the bottom with the “Xaero’s Minimap” keybindings.

7. Enter the world

  1. Start Mumble and connect to our Mumble server
  2. Start Minecraft and verify 1.15.2-forge is selected
  3. Join the server
  4. In Mumble the note Minecraft linked should appear to indicate Mumble and Minecraft work together
  5. gl & hf

8. Get you up to speed

Ingame Keyboard Shortcuts

:video_game: Crafting Cheat Sheet

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If you want to use a more custom skin you can go to Minecraft Skins website and download the ones you like as an image file. In the Minecraft Launcher you can use these image files in the “Skins” section for your character.

Create a private chat channel/room in Mumble

When you are logged in to Mumble and connected to the server, you can create private chat channel/rooms, but you need to register first, if you haven’t already.

Right click your name and choose Register.
Right click on Root, click Add and fill out the info to create your channel.

People can join your room. It will disappear when you log out.

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