voxy 1.21.1 backport

Unofficial backport of MCRcortex/voxy to Minecraft 1.21.1. It is based on j-shelfwood/voxy-neoforge. This fork is not affiliated with upstream, so please don't report issues there.

Source only. Voxy is All Rights Reserved (LICENSE.md), so no releases or CI artifacts are published.

Branch	Loader	Renderer	Shaders
mc1.21.1-embeddium	NeoForge 21.1	Embeddium 1.0.x	Iris 1.8.12 + Monocle
mc1.21.1-fabric	Fabric 0.16+	Sodium 0.8.x	Iris 1.8.x

Build

You need Git and JDK 21. The first build downloads Minecraft and all dependencies, so it takes a few minutes. Later builds are much faster.

1. Install JDK 21

Windows (PowerShell):

winget install EclipseAdoptium.Temurin.21.JDK

macOS:

brew install --cask temurin@21

Linux (Debian/Ubuntu):

sudo apt install openjdk-21-jdk

2. Get the source

git clone --depth 1 -b mc1.21.1-embeddium https://github.com/yyusvf/voxy.git
cd voxy

Without Git, click Code on this branch, then Download ZIP, unpack it and open a terminal in the extracted folder. On Windows, keep the folder path short (for example C:\dev\voxy), because some source paths are deep enough to hit the Windows path length limit.

3. Build

Windows (PowerShell). The first line points the build at JDK 21, even if an older Java comes first on your PATH:

$env:JAVA_HOME = (Get-ChildItem "C:\Program Files\Eclipse Adoptium" -Directory -Filter "jdk-21*" | Select-Object -First 1).FullName
.\gradlew.bat build

macOS and Linux (chmod is only needed after a ZIP download and is harmless otherwise):

chmod +x gradlew
./gradlew build

For the shader variant, add -Pshaders, for example .\gradlew.bat build -Pshaders or ./gradlew build -Pshaders.

4. Install

The jar ends up in build/libs/. A plain build produces voxy-0.2.9-alpha.jar, and build -Pshaders produces voxy-shaders-0.2.9-alpha.jar. Copy one of them into your instance's mods folder and remove any other Voxy jar, because both use the same mod id. The shader variant only changes anything with packs that ship a voxy.json, such as Photon's voxy-support build.

Troubleshooting

• "Gradle requires JVM 17 or later" or "Unsupported class file major version" means the build is running on an older Java. On Windows, run the $env:JAVA_HOME line again in the same window. On macOS, run export JAVA_HOME=$(/usr/libexec/java_home -v 21). On Linux, run export JAVA_HOME=/usr/lib/jvm/java-21-openjdk-amd64.
• "Filename too long" on Windows means the folder path is too deep. Move it somewhere shorter, or run git config --global core.longpaths true and clone again.

mc1.21.1-embeddium

Requires NeoForge 21.1, Embeddium 1.0.x and Forgified Fabric API. Sodium is declared incompatible. Tested in-game in FTB OceanBlock 2 with Complementary and Photon voxy-support.

Changes over j-shelfwood:

• The terrain integration targets Embeddium (org.embeddedt.embeddium.impl.*) instead of Sodium, and the options page uses OptionGUIConstructionEvent.
• The Iris integration is backported to MC 1.21.1 and Iris 1.8.12.
• With shaders, the viewport is no longer set up twice per frame, the shadow pass gets its own viewport and no longer writes the chunk-bound buffer, and the uninitialised shadow viewport no longer crashes.
• GL state, including blending, is restored through GlStateManager, because 1.21.1 caches it.
• renderScale is rounded (#555), the enable toggle applies and persists, and the logo path no longer crashes Embeddium's settings.

Known issues: LODs cast no shadows, and the Photon particle transparency fix is unconfirmed.

Mappings and verification notes are in CLAUDE.md.