Indium — a mod to support Fabric Rendering API in Minecraft

Indium — a mod to support Fabric Rendering API in Minecraft

Indium is an addon to the optimization mod Sodium that adds support for the Fabric Rendering API in Minecraft. Without this layer, mods relying on advanced rendering effects — custom block models, contextual coloring, connected textures — render incorrectly with Sodium: geometry breaks, textures disappear, blocks become invisible. Indium bridges this specific compatibility gap without touching Sodium's optimizations or altering vanilla graphics.

Why Fabric Rendering API is needed

The Fabric Rendering API is an interface through which mods pass their own block and item rendering logic to the game engine: flexible models, dynamic coloring based on adjacent blocks, connected textures, custom geometry. In a normal environment with the Fabric API, this role is fulfilled by a reference implementation called Indigo, which is enabled automatically.

When Sodium is added to a modpack — a mod that completely rewrites the rendering pipeline for performance — Indigo is disabled. Sodium itself in versions prior to 0.6.0 does not implement the Fabric Rendering API internally. Because of this, mods built on this API lose access to their custom rendering layer — their blocks and models stop rendering correctly.

How Indium solves the problem

The addon does not alter Sodium's optimizations or add new visual effects on its own. Instead, it connects a separate implementation of the Fabric Rendering API, built on top of Indigo, and allows third-party mods to use it over the Sodium renderer. For the player, the process looks transparent: Sodium is installed for FPS gains, Indium is added alongside it — and mods that previously refused to work with Sodium due to broken models start correctly displaying their blocks in the inventory and the world.

Typical scenarios where this addon is needed are modpacks with resource packs and mods relying on advanced models: connected textures, improved grass and leaves rendering, custom blocks with complex geometry. Indium is not tied to a specific list — it implements the API itself, so it works with any mod that uses this API.

Performance impact

The addon's own load on FPS is close to zero. Indium merely connects the compatibility layer, while all visual optimization remains on Sodium's side. If you install Indium on a clean modpack without mods using the Fabric Rendering API, nothing will change in the game — neither for the better nor for the worse.

At the same time, mods that utilize this API can themselves load the rendering: complex geometry, dynamic models, or a large number of animated textures take up frames. Indium simply provides a channel for such mods to work but does not speed up their calculations. This addon does not bring a speed boost compared to clean Sodium — it is a compatibility layer, not an optimization.

Configuration

The file indium-renderer.properties in the config folder contains two parameters: always-tesselate-blocks and ambient-occlusion-mode. Both are set to auto by default, which is enough for regular gameplay: the mod itself chooses the optimal behavior depending on other installed mods and graphics settings. There is no need to interfere with this file in the vast majority of modpacks.

Compatibility with Sodium 0.6.0

After the release of Sodium 0.6.0, the situation changed fundamentally: the developers incorporated Fabric Rendering API support directly into the main Sodium code. A separate addon layer is no longer needed, and Indium itself is incompatible with this and all later versions — installing both at the same time causes the game to crash on startup.

Because of this, Indium remains relevant where Sodium 0.5.x is used in the modpack. The latest build of the addon — 1.0.35 — supports Minecraft up to 1.21.1 but only works paired with Sodium 0.5.11, not with 0.6.x. For Minecraft 1.21.2 and newer, there are no separate Indium builds at all, and Sodium 0.6.x is installed there by default — the addon is not used in such modpacks.

Conclusion

Indium allows mods with Fabric Rendering API support to work alongside Sodium versions 0.2.0–0.5.x. This addon does not add its own performance or bring new visual effects — it is a compatibility tool, not an optimization tool. Suitable for players keeping Sodium 0.5.x (up to 0.5.11) on Minecraft versions from 1.16.5 to 1.21.1 and using mods built on the Fabric Rendering API.