S²-Guidance for ComfyUI

This repository provides an attempted implementation of S² guidance arxv:2508.12880 for DIT diffusion models in ComfyUI. I thought it looked interesting when the paper came out and decided to implement it as a personal exercise.

Currently only tested with Chroma and it at least does seem to affect the resulting image, although I do not know for sure if the implementation is correct. It is currently hardcoded to only work with the architecture of Flux models, which includes Chroma, I might change this later.

Usage

You will find the node named as "✨ S2Guidance_DIT" under the "✨ S2GUIDANCE" category. Place the node in your model chain. The paper found a S²-scale of 0.25 a good number for their tests with SD3.5, but in Chroma this causes a grainy and blownout result, a S²-scale of 0.05 seems more appropriate here. Keeping the CFG scale at 3.5 seems to work though. Effects can be subtle but seem to improve sharpness and brightness.

Installation

Install this extension by cloning this repository in your custom_nodes folder with git clone https://github.com/orpheus-gaze/comfyui-s2-guidance-test.