SonarGuidedNoise

SonarGuidedNoise is a custom noise type that mixes a reference latent into your noise stream, so the starting noise itself carries a hint of the reference's structure. Where SonarGuidanceConfig steers the sampler, this node steers the noise - you get composition baked into the starting point, before the sampler ever runs.

What it's for

Think of it as structural guidance at the cheapest possible level. You encode a reference image, feed its latent in here, and the generated noise gets nudged toward that latent's shape - early detail, layout, rough structure - instead of being pure randomness. It slots into the same SONAR_CUSTOM_NOISE chain as everything else in the pack, so you can guide one stage of a noise build and leave the rest free.

How it works

• latent - the reference. This is the structure you're guiding toward.
• method - euler (default) does an Euler step toward the guidance; linear simply lerps the guidance at the given strength. Euler is gentler, linear is more direct.
• guidance_factor - strength, default 0.0125. The tooltip's advice is on point: keep it low so it nudges rather than overpowers. Crank it and the noise becomes the reference image's noise, which is rarely what you want.
• sonar_custom_noise - optional. The noise to combine with the guidance. The tooltip has the honest detail: if you don't attach anything here, your reference gets combined with zeros, so attach a SonarCustomNoise (Gaussian or whatever flavor you like) unless you specifically want pure-reference noise.

Normalization switches follow the pack's standard trio - normalize_ref (default true, normalizes the reference to 1.0), normalize_noise, and normalize_result - plus the usual factor scaling. Output is SONAR_CUSTOM_NOISE, so the guided result can feed another noise node or a Sonar sampler directly.

The recipe that makes sense

The pattern that works: reference latent → this node → with a Gaussian SonarCustomNoise plugged into sonar_custom_noise, guidance_factor in the 0.005–0.02 range, then wire the output to a Sonar sampler or a NoisyLatentLike. The reference becomes a ghost in the noise - visible in early composition, mostly gone by the end. That's the sweet spot. Push guidance_factor toward 0.1+ and the reference starts fighting the prompt.

Gotchas

The reference latent and the sampled latent need to be the same size - same rule as the sampler guidance, same failure mode if you ignore it. And because this is noise-generation territory, remember the pack's reproducibility quirk: whether noise generates on CPU or GPU can vary, so seeds can differ between GPU models. If you're chasing a specific result, pin override_device in SonarCustomNoiseParameters or accept some variance.

Install

ComfyUI Manager → search "ComfyUI-sonar" → Install → restart, or:

cd ComfyUI/custom_nodes
git clone https://github.com/blepping/ComfyUI-sonar

No model files, no extra deps. The author's disclaimer applies here more than most nodes: he's upfront that guidance-style features in this pack are experimental and "probably" imperfect - so treat results as interesting, not as a dependable steering mechanism.