Mappificator

This is a pile of bodging scripts for playing around with Minecraft modding mappings, and has become a tool to generate custom mappings for Forge mod development, based on the official (mojmap) mappings. It exists for several reasons:

Mappificator can merge mappings from several sources.
Unnamed parameters can be auto-named based on their type, such as BlockPos blockPos_ instead of BlockPos p_1748392_1_.
IF desired, cross referencing comments can be added populating methods with their corresponding name in other mappings, such as MCP or Yarn.
Mappificator includes more mappings than other sources, including mappings for lambda methods (not included in Parchment, or historically in MCP), and methods in anonymous classes (not included in Parchment).

As mapping projects, technologies, and toolchains have changed a fair amount in recent modding history, notable previous versions are detailed below:

Minecraft Versions	Mapping Export Format	Mappings Sources
1.17.x (Latest)	Parchment	Parchment, Crane, Yarn
1.16.x	MCP Snapshot	MCP, Yarn

Setup

You must install Maven. (Python will invoke mvn via command line, so it must be on your path.)

To check if Maven is functional, run mvn --version in a console window.

Run mappificator.py with the working directory /<Mappificator Project Folder>/src/. There are a number of command line options that can be used and can be found with mappificator.py --help. In general, there are two that are of note:

-p --publish is required to publish the mappings to the user's maven local.
-v --version sets the output version.

Mappificator produces a parchment formatted mapping export. This can be used with Forge Gradle 5+ using Librarian.

In order to use this in a mod dev environment, you need to edit your build.gradle:

Add mavenLocal() to your repositories:

repositories {
    mavenLocal()
}

And change your mapping version and channel to the one produced by this export, which can be set by the --version flag, and will also be printed to the console at the end of a successful export.

minecraft {
    mappings channel: 'parchment', version: '<VERSION>'

TimeConqueror/mappificator

Mappificator

Setup