Extremely WIP and untested implementation of Sonar sampling for ComfyUI. Currently it may not be even close to working properly but it does produce pretty reasonable results.

Only supports Euler and Euler Ancestral sampling.

Description

See https://github.com/Kahsolt/stable-diffusion-webui-sonar for a more in-depth explanation.

The direction parameter should (unless I screwed it up) work like setting sign to positive or negative: 1.0 is positive, -1.0 is negative. You can also potentially play with fractional values.

Like the original documentation says, you normally would not want to set momentum to a value below 0.85. The default values are considered reasonable, doing stuff like using a negative direction may not produce good results.

Parameters

Very abbreviated section. The init type can make a big difference. If you use RANDOM you can get away with setting direction to high values (like up to 2.25 or so) and absurdly low values (like -30.0). It's also possible to set momentum and momentum_hist to negative values, although whether it's a good idea...

Noise

I basically just copied a bunch of noise functions without really knowing what they do. The main thing I can say is they produce a semi-reasonable result and it's different from the other noise samplers. See credits below.

gaussian: This is the default noise type.
uniform: Might enhance background details?
brownian: This is the noise type SDE samplers use.
perlin
studentt: There's a comment that says it may enhance subject details. It seemed to produce a fairly dark result.
studentt_test: An experiment that may be removed, it doesn't seem to be adding enough noise. You can possibly compensate by increasing s_noise.
pink
highres_pyramid: Not extensively tested, but it is slower than the other noise types. I would guess it does something like enhance details.

You can scroll down to the the examples section near the bottom to see some example generations with different noise types.

Credits

Original Sonar Sampler implementation (for A1111): https://github.com/Kahsolt/stable-diffusion-webui-sonar

My version basically just rips off this Sonar sampler implementation for Diffusers: https://github.com/alexblattner/modified-euler-samplers-for-sonar-diffusers/

Noise generation functions copied from https://github.com/Clybius/ComfyUI-Extra-Samplers with only minor modifications. I may have broken some of them in the process or they may not have been suitable for use and I took them anyway. If they don't work it is not a reflection on the original source.

Examples

Noise Types (img2img)

These were generated with s_noise=1.05 to make the noise effect more pronounced, 30 steps at 0.66 denoise, sonar settings increased slightly to enhance the effect (momentum=0.9, momentum_hist=0.85, direction=1.0, momentum_init=ZERO). It is probably easier to compare using these as the image mostly stays the same as the sonar sampler settings change.

Expand renoise example images

Base

Base image - no Sonar Sampler steps.

Gaussian

Brownian

Perlin

Uniform

Highres Pyramid

Pink

StudentT

StudentT_test

Noise Types (Initial Generations)

These were generated with s_noise=1.1 to make the noise effect more pronounced, default sonar settings (momentum=0.95, momentum_hist=0.75, direction=1.0, momentum_init=ZERO). It may be harder to see the noise effects since the composition can change a lot in initial generations.