Experiments

007

The “no” that isn't there

How do I say “no” to a model that has no negative?

Part 01

The negative nobody read

I build my images in ComfyUI, a program where you connect modules. One module holds the text of what I want (the positive). Another holds the text of what I don't want (the negative). The model asks for both, so I filled in both. Then I looked at how it works inside. I always use a fast setting called CFG 1, and with it the negative is never read. Nothing I wrote there ever did anything.

The one I pickedThe one case that worked: I asked for no hair clip, and the clip is gone.Krea 2 · CFG 1 · NAG strength 4 · negative: hair clip, hair accessory · seed 904031704

3 attempts

I asked for no pink hair

First I tried the easy way: writing the “no” inside the positive, like “no text” or “not a photo”. It got worse. The model reads the word “text” and adds text. What did work was describing the opposite: “plain, unmarked panels” instead of “no text”. Then I installed NAG, an extra module that makes the negative work, and gave it a hard test. My positive asks for pink hair. I put “pink hair” in the negative.

Each frame is an attempt. ✕ it didn't work · ✓ it worked · ○ starting point.
  1. A1Starting point

    The starting point. No negative at all.

    Krea 2 · CFG 1 · seed 904031704 · 65 s
  2. A2It didn't work

    Still pink. But the pose, the framing and the suit all changed, and a “01” appeared on her chest.

    NAG strength 4 · negative: pink hair · 105 s
  3. A3It didn't work

    Twice the strength. Still pink, a little lighter. Now her arms are mechanical, which I never asked for.

    NAG strength 8 · negative: pink hair · 108 s

3 attempts

A teapot, a clip and the shine

Any negative moves the whole image, so comparing against “no negative” tells me nothing. I needed a fairer starting point: a negative that has nothing to do with the image. I used “a teapot, a bicycle”. Then I changed only the negative, twice. Once for something small I never asked for, a hair clip. Once for something my positive does ask for, the shine of the suit.

  1. B1Starting point

    The fair starting point. A negative about nothing, so I can see what a negative does just by being there.

    NAG strength 4 · negative: a teapot, a bicycle · 107 s
  2. B2It worked

    It worked. The clip that kept showing up is gone, and the rest of the image barely moved.

    NAG strength 4 · negative: hair clip, hair accessory
  3. B3It didn't work

    It didn't work. The suit is just as shiny, because my positive asks for it. And the clip is back.

    NAG strength 4 · negative: glossy latex shine, reflections

What I learned

  1. First I describe what I want to see. That is what gives the most control, and it costs nothing.

    Attempts: A1

  2. I never write the name of the thing I want to avoid. The model reads the word and adds it.

    Attempts: A2

  3. A negative removes a small object I didn't ask for. It does not beat something my positive asks for, not even at double strength.

    Attempts: B2, B3, A3

  4. Any negative moves the whole image. To know if one worked, I compare it against an unrelated negative, not against the image with none.

    Attempts: A1, A2, B1

  5. It is slower. Each image went from about 65 seconds to about 105.

    Attempts: A1, A2

The next question

Can I remove one thing without changing everything else?

Experiments

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006

Flat vector neon

Can a diffusion model give me a flat vector look, and not just something that resembles one?

Open

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