🎛️ Noise Control

Noise Control is a small script node for FiLKSampler with one genuinely clever idea inside: it blends the noise from a second seed into your sampling run using a rotation instead of a plain lerp, so the variation stays the same strength across the whole weight range. That distinction is the whole reason this node exists, so let's unpack it.

When you want a controlled variation on an image you like - same prompt, same seed, just a nudge in one direction - the naive approach is mixing the base noise and a variation noise with a linear blend. The problem: a linear mix shrinks the noise magnitude in the middle of the range, which reads as a weaker effective denoise. Your "variation" silently becomes a different-strength image. Noise Control rotates instead - base * cos(θ) + variation * sin(θ) as the weight maps 0→1 to 0→90° - which keeps the result unit-variance at every weight. You're changing direction, not energy. It's the kind of math detail most packs would skip, and this one went out of its way to do it right.

What it does, practically

It doesn't sample on its own. It produces a script object you wire into FiLKSampler's script input, exactly like FiL HighRes Fix. Inputs are short:

• rng_source - cpu or gpu. The GPU option can better match Automatic1111-style noise for the same seed, which matters if you're porting a known-good A1111 generation.
• add_seed_noise - the master switch. Off, the node contributes nothing but an RNG source. On, it blends in the variation.
• seed - the variation seed.
• weight - 0 = base seed only, 1 = variation seed only, 0.5 = an even rotational blend. Default 0.5.

That's it. One output, script, plus an optional script input so you can chain it with HighRes Fix - wire HighRes Fix's script into this node's script, then this node's output into the KSampler. Both scripts merge into the same pass.

When to reach for it

Seed variation is the classic way to explore a composition you already like: hold the prompt fixed, wobble the seed a little, and see which nearby image you prefer. A dedicated node makes that repeatable instead of hand-rolling seed arithmetic. It's also the RNG control you want when a specific seed behaves differently on your hardware than someone else's - picking the device the initial noise is drawn on is the kind of control the stock sampler doesn't expose.

Honest caveats. If you just want a different image, a plain new seed does the same job for free - the value here is controlled variation at a specific strength, not randomness. And the weight slider is easy to misread: it's a blend ratio between two noises, not "how much change." At 0.9 you're mostly the variation seed, which is close to just using that seed directly. The interesting zone is 0.2–0.5, where you get a sibling of the original rather than a stranger.

The README also notes that the legacy Automatic1111 cfg_denoiser patching is deliberately not ported - this pack uses the public comfy.sample API instead, which is both cleaner and less fragile. If you came from A1111 expecting that exact noise behavior, the gpu RNG source is the intended bridge.

Install is pack-standard: Manager search FiL_Design_ImageMind, or clone + pip install -r requirements.txt + restart (ComfyUI 0.3.60+, V3 API). Then drop a FiLKSampler, wire this in, and keep add_seed_noise off until you know what the base seed does on its own.