About

A Fabric mod for Minecraft *.21.4 that enables OptiFine to load and function alongside Fabric API. Handles OptiFine JAR discovery in mods directory, ASM-based class patching for *.21.4 API compatibility (GameRenderer, EntityModel, PostEffectProcessor changes), transformer injection into Fabric's classloading pipeline, mixin conflict resolution, and shader/rendering integration. Supports OptiFine HD U features while maintaining compatibility with other Fabric mods.