Vulkan PostFX

Vulkan PostFX is an experimental VPFX shader pack loader and post-processing framework for Minecraft's modern Vulkan renderer.

It allows external VPFX shader packs to add screen-space visual effects such as color grading, vignette, tone mapping, highlight compression, cinematic look adjustments, and depth/shadow-based experiments.

The project is still experimental, but it already supports external ZIP-based VPFX packs through Minecraft's resource pipeline.

Start here

For the best first experience, install:

• Vulkan PostFX — the loader/runtime
• VPFX Minimal Showcase — the official minimal example pack

Vulkan PostFX is not a full Iris / OptiFine replacement.
The goal is to build a new VPFX workflow for Minecraft’s Vulkan rendering path, starting from reliable external pack execution and gradually moving toward a more complete shader runtime.

Current Progress

Vulkan PostFX already supports:

• scanning external ZIP shader packs under run/shaderpacks/
• reading and parsing pack.json
• selecting the active pack via active_pack_id
• validating VPFX graph structure
• resolving shader references such as <pack_id>:<path>
• supporting non-post/ shader paths
• shader include preprocessing
• materializing external ZIP packs into runtime resource packs
• injecting runtime resource packs into Minecraft’s resource system
• loading external post chains through ShaderManager
• sampling minecraft:scene_color
• capturing scene depth
• providing experimental shadow depth input
• writing VPFX failure diagnostics for broken packs
• running an early experimental native fullscreen passthrough path

This means the project is no longer just “reading ZIP files” or “pretending to load packs.” It already implements:

external ZIP shader pack -> VPFX validation -> runtime resource pack -> external post chain execution

And experimentally:

minecraft:main -> transientColor -> builtin native fullscreen passthrough -> minecraft:main

Project Positioning

What this is

Vulkan PostFX is an experimental shader pack loader and visual runtime for the modern Minecraft Vulkan backend.

It currently focuses on:

• screen-space post-processing
• VPFX shader pack loading
• runtime resource pack materialization
• scene color / depth / shadow inputs
• diagnostics for broken packs
• early native runtime experiments

What this is not

Vulkan PostFX is not yet a mature drop-in replacement for Iris or OptiFine.

It does not currently provide full traditional shader pipeline compatibility, and most Iris / OptiFine shader packs cannot be used directly without porting.

A more accurate description of the current state is:

• a working VPFX ZIP shader pack loader
• a post-effect based execution backend
• an experimental Vulkan shader runtime foundation
• an early native runtime research project

Implemented Features

1. External VPFX Pack Loading

Supports loading ZIP-based VPFX shader packs containing:

• pack.json
• post_effect/main.json
• shaders/<path>.vsh
• shaders/<path>.fsh
• optional textures and include files

Shader references use:

<pack_id>:<path>

For example:

vpfx_minimal_showcase:composite/final

which resolves to:

shaders/composite/final.vsh shaders/composite/final.fsh

2. Runtime Namespace Rewriting

External packs are rewritten into isolated runtime namespaces to avoid conflicts with built-in resources and other packs.

3. Runtime Resource Pack Injection

External ZIP contents are materialized into runtime resource packs during startup / resource reload and injected into Minecraft’s client resource system.

4. External Post Chain Execution

Vulkan PostFX can load external post chains through Minecraft’s ShaderManager and execute them through the current minecraft_postchain backend.

5. Scene / Depth / Shadow Inputs

Current VPFX runtime inputs include:

minecraft:scene_color vulkanpostfx:scene_depth vulkanpostfx:shadow_depth minecraft:main

These are used for scene-color effects, depth-based experiments, and shadow-depth debugging.

6. Failure Diagnostics

When a VPFX pack fails to load or execute, Vulkan PostFX can generate diagnostic information to help identify issues such as:

• missing shader files
• invalid graph targets
• sampler mismatch
• shader path errors
• external target problems
• pipeline creation failures

7. Experimental Native Runtime Milestone

Vulkan PostFX is gradually moving beyond Minecraft’s PostChain backend.

Current experimental native runtime progress includes:

• native runtime support checks
• resource mapping dry-run
• same-target hazard detection
• transient color target planning
• mainTarget -> transientColor copy validation
• builtin native fullscreen passthrough draw
• opt-in diagnostic mode that can skip the external PostChain path after a successful native passthrough draw

This is still experimental and opt-in.

User VPFX shaders are not fully executed natively yet.

Current Available Sample

VPFX Minimal Showcase

The official minimal example pack demonstrates:

• VPFX pack.json
• graph-based post effect configuration
• non-post/ shader paths
• minecraft:scene_color sampling
• minecraft:main output
• basic screen-space look adjustment

It is the recommended starting point for testing Vulkan PostFX.

Usage

1. Place a shader pack

Put the ZIP shader pack into:

run/shaderpacks/

A template/example pack is available on the project page.

2. Select the active pack

Edit the config file:

run/config/vulkanpostfx.json

Example:

{ "active_pack_id": "vpfx_minimal_showcase" }

3. Launch the game

When the client starts, the loader will:

• scan ZIP files
• parse available VPFX packs
• select the active pack
• validate the graph
• materialize runtime resources
• inject runtime resources into the client resource system
• attempt to load the corresponding external post chain

4. Toggle the effect

By default, press:

F8

to toggle the current VPFX effect.

Press:

F9

to toggle the experimental shadow depth debug view.

Architecture Overview

[shaderpacks/*.zip] | v [VPFX Manifest / Graph Parse] | v [Active Pack Selection] | v [Runtime Materialization] | v [Runtime Resource Pack Injection] | v [minecraft_postchain backend] | v [External VPFX Post Chain Execution]

Experimental native runtime path:

[VPFX Native Runtime] | v [mainTarget -> transientColor] | v [builtin native fullscreen passthrough] | v [minecraft:main]

Current Limitations

Vulkan PostFX is still alpha software.

Not fully supported yet

The following traditional shader pipeline components are not fully supported:

• gbuffers_*
• full shadow.* compatibility
• full composite.* compatibility
• screen-space reflections
• volumetric fog
• natural cloud rendering
• material-aware lighting
• dimension-specific shader routing such as world1/ and world-1/
• direct Iris / OptiFine shader pack compatibility

Native Runtime Limitations

The native runtime currently supports only an experimental builtin fullscreen passthrough path.

It does not yet support:

• user shader native execution
• multi-pass native execution
• custom native render targets
• native scene depth input
• native shadow depth input
• compute shaders
• native volumetric lighting
• native cloud rendering
• RT / path tracing

Most Suitable Development Direction Right Now

The recommended next steps are:

1. improve VPFX pack authoring workflow
2. continue validating screen-space look layers
3. improve final-pass translation quality
4. implement user shader native execution
5. gradually introduce native multi-pass graphs
6. expand depth and shadow support
7. eventually explore lighting, clouds, and RT-lite experiments

Design Philosophy

The core idea of Vulkan PostFX is not to force all traditional shader semantics into Vulkan at once.

Instead:

first establish a truly executable external shader chain, then gradually bring back the visual logic that matters.

In practice, that means:

• first make external VPFX packs actually run
• then improve visual fidelity
• then expand the runtime
• then gradually approach more advanced shader pipeline capabilities

Notes

This is still a fast-evolving experimental project.

If you are looking for a ready-made, fully compatible Iris / OptiFine replacement, Vulkan PostFX is not there yet.

But if you care about:

• Minecraft’s Vulkan renderer
• VPFX shader pack experiments
• external ZIP shader pack loading
• modern runtime resource pack injection
• scene/depth/shadow based post effects
• experimental native render graph runtime development

then this project is built exactly for that.

Update Policy

This mod is expected to follow Minecraft snapshot updates quickly.

The project may update weekly, or more often when Minecraft snapshots or VPFX runtime milestones require it.