Vulcade

Vulcade

Loadable shader packs that work on Minecraft 26.2’s Vulkan renderer.

Minecraft 26.2 replaced the 17-year-old OpenGL pipeline with a graphics backend abstraction and
shipped an experimental Vulkan renderer alongside it. The catch: existing shader mods don’t support
it. Iris is OpenGL-only, so switching Graphics API to Vulkan currently means giving up shaders
entirely.

Vulcade fills that gap. It runs shader packs through Minecraft’s own post-effect system, which means
the active backend compiles the shaders itself — under Vulkan your pack’s GLSL goes through
Mojang’s GLSL-to-SPIR-V path and executes on the Vulkan command encoder. Vulcade issues no graphics
calls of its own, so the same code works on Vulkan and OpenGL with no backend-specific paths.

Features

• Filmic colour grading — ACES tonemap, contrast, warm highlights against cool shadows, vibrance
• Bloom — soft-knee bright pass with a multi-stage separable blur
• Sun glare — a warm halo that tracks the sun on screen
• Volumetric light shafts — god rays that work for the sun and for any bright aperture, like a cave opening
• Ore glow — ores, torches and lava read as self-illuminated in dark caves
• Per-scene looks — separate chains for underwater (with refraction wobble), the Nether, and the End
• Four quality profiles — Low / Medium / High / Ultra change the actual pass count, not just numbers, so Low is genuinely cheaper
• In-game screen — K to pick a pack and quality, J to toggle
• Fully tunable — every grade value lives in plain JSON. Edit, press F3+T, no GLSL required

Requirements

• Minecraft 26.2
• Fabric Loader 0.19.3+ and Fabric API
• Java 25 (bundled with the official launcher from 26.1 onward)
• For the Vulkan path: Video Settings → Graphics API → Prefer Vulkan. Requires Vulkan 1.2 with dynamic rendering and push descriptors; on macOS this runs through MoltenVK. OpenGL also works.

What this is not

Stated plainly, so you know what you’re installing:

• Not an Iris or OptiFine shader pack loader. OptiFine-format packs (gbuffers_*, composite*, shadow*) will not load. Those formats assume control of Minecraft’s terrain and shadow shaders, and a uniform contract that doesn’t exist on the Vulkan backend.
• No shadow maps, water reflections, waves or volumetric clouds. These aren’t features that are nearly finished — they’re outside what post-processing can do. Shadows need a depth map rendered from the sun’s viewpoint during world rendering; water reflections need the water surface’s normals; volumetric clouds are geometry. A post pass only ever receives the finished 2D colour buffer.
• Ore glow is not per-block emissive lighting. A post pass never learns which block a pixel came from. It keys on brightness and saturation, so ores, torches and lava glow — and so will a bright saturated non-ore block in a dark room.

If you want full lighting-model shaders, you want Iris, on OpenGL. Vulcade is for people who want the
Vulkan backend and a good-looking game.

Writing your own pack

A pack is a folder or .zip in shaderpacks/ containing a vulcade.json manifest, post_effect
chain JSON, and shaders/post/*.fsh laid out like a resource pack. Chains use vanilla’s own
post-effect format, so if you’ve written a vanilla post shader, you already know it. Every pass gets
SamplerInfo (OutSize/InSize) and vanilla’s Globals block (GameTime, ScreenSize, camera
position) for free.

Ships with tools/validate_pack.py, which checks a pack without launching the game — Minecraft only
compiles a chain the first time it runs, so a broken Nether chain otherwise stays silent until you
stand in the Nether.

Credits

By Chris Do. MIT licensed.

The bundled pack’s look is inspired by Complementary Shaders; no code from it is used or included.