Worldgen Devtools

⭐ — (76 endorsements) 📥 8,958 downloads 📌 v1.4.0+26.3-snapshot-2 📅 4/18/2024
🟡 Updated this year

By jacobsjo · fabric

⬇ Download Mod Source: Modrinth ↗ 📅 Updated: 7/1/2026 📅 Created: 4/18/2024
⚠️ Install Order · 2 steps
1🛠️ Forge — Minecraft Forge (mod loader) Download ↗
2🛠️ Fabric — Fabric Loader Download ↗

Install in this order, then this mod last — most mods fail to load without their framework and dependencies in place.

🔍 Analysis

  • 👍 0.8% endorsement rate
  • 🏆 #144 of 893 fabric mods in this game by downloads

📋 About This Mod

# Worldgen Devtools This is a mod that provides tools simlifying the creation of worldgen datapacks and mods. ## Registry (worldgen) Reloading *Needs be enabled per world using the `reloadRegistries` gamerule.* **Warning: While this should be fairly stable, this tool can probably still corrupt your worlds. So only enable in testing worlds** Allows the reloading of registry content (such as all worldgen data) using the `/reload` command, or when enabling or disabling a datapack using the `/datapack` command. Without this mod, the world needs to be reopened for changes to take effect. Entries are never removed from registries, even when no longer present in the loaded datapacks. Instead, they are marked as outdated, so that they don't have an effect on world generation and can't be referenced from other datapack files. Existing chunks can still use the outdated entries though, until the world is reopened. The world-height and noise shape (i.e. height and cell size) can't be reloaded. ### Client Syncronization Some reloaded data affects the client, such sa biome colors, dimension types, and armor trims. In multiplayer, dimension and biome effects need to be synconized. This causes the client to redraw all chunks. If this behaviour is undesireble, it can be disabled using the `syncAfterRegistryReload` gamerule. ## Reset Chunks !(docs/images/noise_only.png) The `/resetchunks ` command resets the chunks surrounding the player in the specified range - regenerating it with the current worldgen data and settings. Defaults to `0` (i.e. only the current chunk). If you want to reset a structure, you need to reset the chunk of the structure start. *Note: This implementation actually used the normal worldgen thread, and thus has much better performance than the unregistered vanilla command.* ## Colored Jigsaw Blocks !(docs/images/colored_jigsaws.png) Colors Jigsaw blocks based on their specified "Name" or "Target Name". If a "Name" other than `minecraft:empty` is set, the jigsaw block is colored based on the hash of the "Name". Otherwise, if a "Target Name" other than `minecraft:empty` is set, the jigsaw block is colored based on the hash of the "Target Name". If both "Name" and "Target Name" are set to `minecraft:empty` the jigsaw block is rendered *deactivated*, with grayed out arrows and connectors. In the inventory, if a jigsaw block has stored NBT (Shift+Pick), then it is rendered with the associated color and a tooltip indicated the "Name", "Target Pool", and "Target Name". ## Get Density Command Command to debug the values of density functions are any position. ### `/getDensity density_function <df> ` Returns the value of the density function `df` at the specified postion (or the position of the player) ### `/getDensity noise_router <entry> ` Returns the value of the density function specified in the given entry of the noise router of the current dimension at the specified postion (or the position of the player) ## Profiling of Worldgen Performance !(docs/images/chunk_profiling.png) The time it took to generate each step of each chunk is recorded and saved in each chunk. To access it, use the `/chunkprofiling <range>` command. Range controlls the amount of chunks to average the performance over; defaults to `0`. ## Locate Feature !(docs/images/locate_feature.png) Use `/locate feature <configured_feature>` to locate a configured feature nearby. If the current chunk contains the feature multiple times, it will list the up to 5 closest positions. This only works if the chunk is generated while this mod is installed. ## Logging improvements - Empty height ranges in placed features also log the placed feature that causes the problem. ## Chase The `/chase` command provides options to syncronize of the player positions between two different instances of Minecraft. Usefull for comparing differences in worldgen. This is a vanilla command, simply registered by this mod. ## Gamerules Gamerules added by this mod: | Gamerule | | |----------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | `maxChunkStatus` | Which steps of world generation should be done? <br/> -> `NOISE_ONLY`: Generates stone, air, water and lava only. <br/> -> `SURFACE`: Applies the surface rules. <br/>

# Worldgen Devtools

This is a mod that provides tools simlifying the creation of worldgen datapacks and mods.

## Registry (worldgen) Reloading

Needs be enabled per world using the `reloadRegistries` gamerule.

Warning: While this should be fairly stable, this tool can probably still corrupt your worlds. So only enable in testing worlds

Allows the reloading of registry content (such as all worldgen data) using the `/reload` command, or when enabling or disabling a datapack using the `/datapack` command. Without this mod, the world needs to be reopened for changes to take effect.

Entries are never removed from registries, even when no longer present in the loaded datapacks. Instead, they are marked as outdated, so that they don't have an effect on world generation and can't be referenced from other datapack files. Existing chunks can still use the outdated entries though, until the world is reopened. The world-height and noise shape (i.e. height and cell size) can't be reloaded.

### Client Syncronization

Some reloaded data affects the client, such sa biome colors, dimension types, and armor trims. In multiplayer, dimension and biome effects need to be synconized. This causes the client to redraw all chunks. If this behaviour is undesireble, it can be disabled using the `syncAfterRegistryReload` gamerule.

## Reset Chunks !(docs/images/noise_only.png)

The `/resetchunks []` command resets the chunks surrounding the player in the specified range - regenerating it with the current worldgen data and settings. Defaults to `0` (i.e. only the current chunk). If you want to reset a structure, you need to reset the chunk of the structure start.

Note: This implementation actually used the normal worldgen thread, and thus has much better performance than the unregistered vanilla command.

## Colored Jigsaw Blocks !(docs/images/colored_jigsaws.png)

Colors Jigsaw blocks based on their specified "Name" or "Target Name". If a "Name" other than `minecraft:empty` is set, the jigsaw block is colored based on the hash of the "Name". Otherwise, if a "Target Name" other than `minecraft:empty` is set, the jigsaw block is colored based on the hash of the "Target Name".

If both "Name" and "Target Name" are set to `minecraft:empty` the jigsaw block is rendered deactivated, with grayed out arrows and connectors.

In the inventory, if a jigsaw block has stored NBT (Shift+Pick), then it is rendered with the associated color and a tooltip indicated the "Name", "Target Pool", and "Target Name".

## Get Density Command

Command to debug the values of density functions are any position.

### `/getDensity density_function []`

Returns the value of the density function `df` at the specified postion (or the position of the player)

### `/getDensity noise_router []`

Returns the value of the density function specified in the given entry of the noise router of the current dimension at the specified postion (or the position of the player)

## Profiling of Worldgen Performance

!(docs/images/chunk_profiling.png)

The time it took to generate each step of each chunk is recorded and saved in each chunk. To access it, use the `/chunkprofiling ` command. Range controlls the amount of chunks to average the performance over; defaults to `0`.

## Locate Feature

!(docs/images/locate_feature.png)

Use `/locate feature ` to locate a configured feature nearby. If the current chunk contains the feature multiple times, it will list the up to 5 closest positions. This only works if the chunk is generated while this mod is installed.

## Logging improvements - Empty height ranges in placed features also log the placed feature that causes the problem.

The `/chase` command provides options to syncronize of the player positions between two different instances of Minecraft. Usefull for comparing differences in worldgen. This is a vanilla command, simply registered by this mod.

## Gamerules

Gamerules added by this mod:

| Gamerule | | |----------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | `maxChunkStatus` | Which steps of world generation should be done? -> `NOISE_ONLY`: Generates stone, air, water and lava only. -> `SURFACE`: Applies the surface rules.

🤖 AI-enhanced — based on mod data

📊 Mod Details

Game
Minecraft Mods
Author
jacobsjo
Version
1.4.0+26.3-snapshot-2
Downloads
8,958
Endorsements
76
Category
fabric
Created
4/18/2024
Updated
7/1/2026
Game Versions
26.3-snapshot-2
Tags
utility, worldgen

🔧 How to Install Minecraft Mods Mods

Download from Modrinth. Use Prism Launcher or drop into your mods folder.

📖 Full step-by-step install guide for Minecraft Mods →

Visit the official mod page for specific installation instructions for this mod.

🎮 Need cheat codes or console commands? Check ur gaming wiki for Minecraft Mods commands, item IDs, and more.

❓ Frequently Asked Questions

Which Minecraft Mods versions does Worldgen Devtools support?

The author lists 26.3-snapshot-2. Other versions may work but are untested by the author.

What is the latest version of Worldgen Devtools?

Version 1.4.0+26.3-snapshot-2, published 2026-07-01 with 8,958 downloads recorded at the source.

Keep browsing — more Minecraft Mods mods await

📋 All Minecraft Mods Mods 🏆 Top 25 📂 More fabric 👤 More by jacobsjo 🔎 Similar Mods 🌐 Best fabric (All Games) 🔀 Check Compatibility ⚖️ Compare Mods 🆕 New Mods