Ciderlight

A Fabric (and NeoForge, beta) mod for Minecraft Java 26.3 that adds a native Apple Metal rendering backend and a built-in, Metal-native shader pipeline.

Download from CurseForge.

Minecraft 26.3 split its renderer into swappable backends (OpenGL and Vulkan). Ciderlight adds a third that talks to Metal through a small Objective-C bridge (src/main/native/ciderlight.m) called via Java's FFM API. The game's GLSL shaders are compiled to SPIR-V and translated to Metal Shading Language with SPIRV-Cross, so vanilla rendering, resource packs and core-shader packs keep working.

M1 Pro, 1708x960, render distance 16, vsync off, same jungle scene:

Later optimisations raised shaders-on further (164–173 → 205–208 median FPS on another test save); the frame is now CPU-limited. Reproduce with ./gradlew runClient -Pworld=<save> -Pbench=20 (add -Pvanilla or -Pnoshaders).

Written for this backend, not ported from an OptiFine/Iris pack, so they only run on Ciderlight.

• Lighting: sun-aware direct and sky light replacing vanilla's fixed face shading, warm torch falloff, full-bright flames.
• Held light: torches, lanterns and other light sources in hand light the area around the player (and other players).
• Shadows: real-time sun and moon shadows, including foliage, with coloured light through stained glass, ice and water.
• Sky and atmosphere: directional sky gradient, layered volumetric mist with light shafts and aerial perspective.
• Ambient occlusion: screen-space GTAO for soft contact shadows.
• Waving foliage: leaves, grass, crops and vines sway in a world-anchored wind, shadows included.
• Clouds: opaque, volume-shaded clouds lit by the sun's position.
• Water: animated waves, refraction, depth absorption, foam, sun glint, rain ripples and screen-space reflections.
• Underwater: volumetric light, absorption and caustics.
• Composite: sun rays, a gentle filmic grade and vignette.

Visual references: Complementary Shaders and Bliss (Chocapic13 edit). All Metal code is original.

Open Options > Video Settings > Ciderlight... (under the graphics preset):

• Shaders: Off (Metal renderer, vanilla look), Low or High. A-series GPUs and the plain M1, M2, M3 and M4 default to Low (smaller shadow maps, fewer samples, lighter water reflections, world drawn at about two thirds resolution); everything else defaults to High.
• Shadows, Waving Plants, Water Reflections, Water Waves, Ambient Occlusion: each on by default. Shadows off also skips the shadow maps and light shafts, which is the biggest saving.
• Render Scale: the world's resolution, Auto (the quality's own) or 50 to 100%.

Shadows and Ambient Occlusion apply at once; everything else applies after a restart. All of it is saved in config/ciderlight.properties.

JVM -D overrides: ciderlight.quality=low|high, ciderlight.shaders=false, ciderlight.renderScale=<0.25–1>, ciderlight.shadowSize, ciderlight.shadowDistance, ciderlight.fogDistance, ciderlight.waterReflections=false, ciderlight.waterWaves=false, ciderlight.waving=false, ciderlight.ao=false, ciderlight.shadows=false, ciderlight.framePacing=true, ciderlight.debug=true, ciderlight.disable=true (fall back to vanilla backends). An override wins over the settings page, which greys that option out.

1. Install Fabric Loader for Minecraft 26.3 (https://fabricmc.net/use/installer/).
2. Download the latest Ciderlight JAR from Releases and copy it into ~/Library/Application Support/minecraft/mods/.
3. Launch the Fabric profile. Ciderlight is client-side only, so it works on any server.

For NeoForge (beta), install NeoForge for 26.3 instead and use the ciderlight-neoforge-<version>.jar. Optionally add --enable-native-access=ciderlight to the JVM arguments to silence Java's native-access warning, and leave NeoForge's version check on: with it off, NeoForge 26.3's title screen crashes.

Don't install Sodium, Iris or Sodium Extra alongside it: Fabric won't launch with them (see Known limitations).

Requires an Apple Silicon Mac on macOS 14 or later. On other machines the mod turns itself off and the game uses its default renderer.

Requires Xcode command-line tools and a Java 25 JDK (set JAVA_HOME to it).

./gradlew build                 # jar in build/libs/
./gradlew runClient             # dev client
./gradlew installMod            # build and copy into the launcher's mods folder
./gradlew -p neoforge build     # NeoForge jar in neoforge/build/libs/ (same sources, a build of its own)
./gradlew -p neoforge runClient # NeoForge dev client (its asset download needs a Java 21 runtime too)
python3 tests/check_shaders.py  # compile shader variants and run GPU regressions

GitHub Actions builds the JAR and native library from source; releases use that build's JAR unchanged.

• Ambient occlusion and reflections only see what is on screen.
• Entities in caves can be darkened by the sun shadow test.
• No bloom/HDR.
• OptiFine/Iris shader packs (e.g. Complementary) are not supported.
• NeoForge (beta): stencil tests that NeoForge lets mods add to pipelines are not applied yet.
• Sodium (and add-ons that need it, such as Iris and Sodium Extra) can't run alongside Ciderlight: Sodium's chunk renderer uses a multi-draw call the Metal backend doesn't provide. Fabric will refuse to launch and list them as incompatible; this is intentional. Remove them from the mods folder.

Copyright 2026 Richard Qi. Apache License 2.0; keep the NOTICE file when redistributing.