Perturbed-Attention Guidance for ComfyUI/Forge

Implementation of Self-Rectifying Diffusion Sampling with Perturbed-Attention Guidance (D. Ahn et al.) as an extension for ComfyUI and SD WebUI Forge.

Tested to work with SD1.5 and SDXL.

Note

Paper and demo suggest using CFG scale 4.0 with PAG scale 3.0 applied to U-Net's middle layer 0, but feel free to experiment.

Sampling speed without adaptive_scale is similar to Self-Attention Guidance (x0.6 of usual it/s).

Installation

ComfyUI

git clone https://github.com/pamparamm/sd-perturbed-attention.git into ComfyUI/custom-nodes/ folder.

SD WebUI (Forge)

git clone https://github.com/pamparamm/sd-perturbed-attention.git into stable-diffusion-webui-forge/extensions/ folder.

SD WebUI (Auto1111)

Currently not implemented. PRs are welcome!

Parameters

• scale: PAG scale, has some resemblance to CFG scale - higher values can both increase structural coherence of the image and oversaturate/fry it entirely.
• adaptive_scale: PAG dampening factor, it penalizes PAG during late denoising stages, resulting in overall speedup. Should be << than scale.
• unet_block: Part of U-Net to which PAG is applied, original paper suggests to use middle.
• unet_block_id: Id of U-Net layer in a selected block to which PAG is applied. PAG can be applied only to layers containing Self-attention blocks.