VoxLib

A Kotlin library for creating, combining, rotating, simplifying, and debugging Minecraft voxel shapes.

Language
Kotlin
Loaders
Fabric, NeoForge
Docs
KDoc
Status
Actively maintained

01Overview

VoxLib originally started as utility code inside Wooden Accents. I was constantly dealing with Minecraft's VoxelShape API to build and rotate collision and outline shapes, and a lot of that code ended up being repetitive. Eventually it made more sense to turn those utilities into a separate library that I could reuse in other mods and that other developers could use too.

02Technical stack

Language Kotlin
Mod loaders FabricNeoForge
Documentation KDoc

03Features

  • Create cuboids using Minecraft's familiar 0–16 block coordinates
  • Combine and conditionally assemble voxel shapes
  • Rotate and flip shapes without rewriting them for each direction
  • Built-in shape helpers for common block types
  • Caching for repeated shape operations
  • Simplified outlines and in-game debugging tools
  • Kotlin API documentation and usage guides, including Java interoperability

04Architecture

VoxLib is written primarily in Kotlin and uses a shared module for its shape operations, caching, and other reusable functionality. Loader-specific modules connect it to Fabric and NeoForge. The idea is to provide a cleaner API without trying to replace Minecraft's underlying voxel shape system.

05Challenges

Making directional shapes less repetitive

One of the original problems I wanted to solve was having to manually define essentially the same shape for different block directions. Rotation and transformation helpers let me define a shape once and adapt it for different orientations. This made my block code much easier to read, especially when dealing with connected or more detailed models.

Keeping the utilities efficient

Voxel shapes are queried pretty frequently, so I didn't want convenience functions to come with unnecessary overhead. I added caching for repeated operations and worked on ways to simplify shapes when full detail isn't needed. Making a library convenient is nice, but it's not very helpful if it ends up slowing down the mods using it.

06Status

Actively maintained

VoxLib is an actively maintained dependency for Wooden Accents and is also available for other mod developers to use. It supports Fabric and NeoForge on newer Minecraft versions, with older versions kept available for compatibility. I'm continuing to improve its API, documentation, and performance as I work on other mods.

© 2026 Mathew Kennedy-Brewer Built with SvelteKit & TypeScript