Actinium is an experimental rendering and shader compatibility mod for Minecraft 1.12.2 on Cleanroom Loader. It aims to bring a more modern rendering pipeline to the legacy client while keeping shader packs, classic modded content, and performance-oriented rendering work in the same world.
The project currently combines work around Celeritas, GLSM, GTNHLib, and an Iris-style shader pipeline. Its focus is practical compatibility: terrain rendering, entity rendering, shadow passes, post-processing stages, shader uniforms, framebuffer ownership, and the OpenGL state transitions that old and new renderers both depend on.
- Reworks the Minecraft 1.12.2 client rendering path around a modernized pipeline.
- Integrates Celeritas terrain rendering concepts into the Cleanroom environment.
- Takes over and stabilizes GLSM-related OpenGL state handling.
- Implements an Iris-inspired shader pass model, including
shadow,gbuffers,prepare,deferred,composite, andfinalstages. - Improves compatibility with shader packs that expect modern framebuffer, uniform, and program-binding behavior.
- Keeps legacy modded rendering paths in view, including entities, block entities, particles, weather, sky rendering, water reflections, and shadow rendering.
Actinium is under active development. It is not a drop-in replacement for every Minecraft 1.12 rendering stack yet, and shader pack behavior can still vary by pack, preset, driver, and mod list.
The current development direction is compatibility-first:
- preserve expected vanilla and modded rendering behavior;
- make shader pack pipeline stages predictable;
- reduce hidden OpenGL state leaks between legacy rendering and shader rendering;
- keep regressions visible through focused tests and manual shader-pack checks.
Shader packs such as MakeUp, BSL, and Complementary are useful compatibility targets during development, but support should be treated as ongoing work rather than a finished compatibility matrix.
- Minecraft 1.12.2
- Cleanroom Loader
- Java toolchain matching the project Gradle configuration
- A graphics environment capable of running shader packs used for testing
From the project root:
.\gradlew.bat build --no-daemonFor a faster compile-only check:
.\gradlew.bat compileJava --no-daemonThe produced mod artifact can be used in a compatible Cleanroom-based Minecraft instance.
src/contains the main Actinium and Celeritas integration code.glsm/contains the embedded GLSM-side integration.GTNHLib/contains the embedded GTNHLib pieces used by the project.docs/contains development notes, compatibility gaps, and future documentation.buildSrc/contains Gradle build logic and dependency definitions.
Actinium builds on ideas, code, and compatibility research from several projects. The items below are listed to make those roots visible; each upstream project remains governed by its own license and authorship.
- Celeritas: provides much of the original Minecraft 1.12 performance-mod foundation and terrain-rendering direction that Actinium continues to adapt.
- GLSM: provides shader-pack loading, shader state management, and compatibility behavior that Actinium integrates and stabilizes.
- GTNHLib: provides utility code and compatibility infrastructure used by the embedded legacy rendering stack.
- Iris: serves as a major reference for shader pipeline structure, pass ordering, framebuffer behavior, and shader-pack expectations.
- GLSL Transformation Library: used for GLSL parsing and transformation work needed by shader compatibility code.
- Sodium: informs the broader performance-oriented rendering model and modern Minecraft renderer design.
- Angelica and the GTNH rendering ecosystem: useful references for Minecraft 1.7/1.12-era shader compatibility, legacy OpenGL behavior, and modded-client integration.
- Cleanroom Loader: provides the target Minecraft 1.12.2 runtime environment.
Actinium is distributed under the license in LICENSE.
Code originating from other projects, along with compatibility changes made to that code, remains under the original license of the respective upstream project unless explicitly stated otherwise in the relevant source files.