noobai-vpred-prompting

name: noobai-vpred-prompting disable-model-invocation: true description: Prompting rules for the Laxhar Labs NoobAI-XL v-prediction anime / illustration model. Use when the user asks to generate / draw / render an anime image on a NoobAI v-pred workflow. NoobAI uses artist:name syntax and is e621-trained (requires anti-furry negatives); the v-prediction variant has strict Euler-only, low-CFG, and zsnr constraints.

NoobAI-XL V-Pred Prompting

NoobAI-XL V-Pred is Laxhar Labs' Illustrious-XL fine-tune on Danbooru + e621 (NebulaeWis's e621-2024-webp-4Mpixel), running in v-prediction mode. Write the prompt and negative you pass to the generate_image tool per the rules below to drive it well on the first call. The v-pred constraints are non-negotiable - the model card opens with "THIS MODEL WORKS DIFFERENT FROM EPS MODELS!" The rules here are specific to the v-prediction variant; an eps-prediction model wants different sampler / CFG settings.

NoobAI supports Danbooru and e621 tag namespaces plus natural-language captions. Because of the e621 training, you must add anti-furry tags to the negative when you want pure anime output.

Safe default when unsure: use the NoobAI v-pred workflow; lead the prompt with masterpiece, best quality, newest, absurdres, highres, safe,, add roughly 8-15 caption-order tags for the subject, and always pass the recommended negative below including its anti-furry block. Keep the workflow at Euler + v-prediction + zsnr and CFG 4-5. Everything below is how to do better than this default when the request calls for it.

The generate_image call

Do not pass inputImage unless the workflow is a NoobAI img2img variant.

Positive prompt recipe

1. Required prefix: masterpiece, best quality, newest, absurdres, highres, safe,
   • newest is a period tag for 2021-2024 art - swap it (see Date tags) if you want an older look.
   • Drop safe only if the user explicitly wants sensitive / nsfw; mirror the change in the negative.
2. Caption order: <1girl/1boy/1other/...>, <character>, <series>, <artists>, <special tags>, <general tags>, <other tags>.
3. Artists use artist:name syntax, comma-joined: artist:john_kafka, artist:nixeu, artist:quasarcake. Multi-word artist names keep the underscore (john_kafka). Do not use an @ prefix on artists.
4. Lowercase tags, spaces over underscores in general tags; multi-word Danbooru proper nouns may keep underscores.
5. Escape literal parentheses with backslash: arlecchino \(genshin impact\), horror \(theme\).
6. Name then describe characters. Multiple characters -> describe each separately to avoid conflation.
7. Be specific. Like Illustrious, NoobAI has no aggressive aesthetic baked in - short prompts come out bland.
8. Optional aesthetic boost: add very awa to the positive prompt (top 5% waifu-scorer aesthetic) when you want maximum polish; pair with worst aesthetic in the negative.

Negative prompt recipe

Start from the model card's recommendation and adjust:

nsfw, worst quality, old, early, low quality, lowres, signature, username, logo, bad hands, mutated hands,
mammal, anthro, furry, ambiguous form, feral, semi-anthro

The mammal, anthro, furry, ambiguous form, feral, semi-anthro block is what keeps the e621 training from leaking into pure anime output - keep it unless the user actually wants furry/anthro art.

Add situational terms:

• worst aesthetic when you used very awa in the positive.
• text, watermark, multiple views, extra digits, jpeg artifacts for cleanup.
• Drop nsfw if the user wants sensitive/explicit (and remove safe from the positive).

Tag reference

Quality tags

Aesthetic tags

Date tags

For a specific year, use year 2023, year 2024, etc.

Safety tags

Generation settings

Sampler / scheduler are workflow-level - if generations look mushy, the workflow likely isn't configured for v-pred. Tell the user to verify the workflow file has Euler + v_prediction + zsnr before retrying.

If outputs are oversaturated, the Civitai page recommends a CFG-Rescale node at 0.2 to tame v-pred contrast. That is a workflow-level addition - mention it when the user reports burned-looking renders.

Prompt enhancement (enhance)

The generate_image tool has an opt-in enhance option that routes your prompt through a separate model before the render to rewrite it into NoobAI's native protocol - the prefixed, caption-ordered Danbooru / e621 tag list this guide describes.

• It is opt-in. Pass enhance: true on the call (or a workflow/config default turns it on). When off, your prompt is sent as-is.
• Use it when the incoming prompt is thin (a few words) and you want a one-shot upgrade to a full tagged prompt. When you have already built a careful tagged prompt, leave enhance off - it only adds latency and risks drifting from your intent.
• Scene continuity. Pass the context arg alongside enhance to hand the enhancer background to honour (character facts, ongoing scene, wardrobe) without depicting it literally. It is ignored when enhance is off.
• Negative. The enhancer builds on whatever baseline negative you pass and returns a refined one - it must keep the anti-furry block (see the negative recipe).

If you are enhancing a prompt rather than rendering

You may be reading this not to call generate_image yourself, but as guidance handed to the prompt-enhancement step: you were given a rough positive prompt, a baseline negative, and the target workflow's protocol, and you must return a single JSON object {"prompt", "negative"} and nothing else. In that role:

• Act only on the prompt-writing rules above - the required prefix and caption order in the positive recipe and the negative recipe. The generation-settings and tool-arg tables do not apply - you do not pick a workflow or call any tool.
• Translate and enrich, do not reinvent. Keep the incoming subject and intent; lead with masterpiece, best quality, newest, absurdres, highres, safe,, write artists as comma-joined artist:name (no @), use lowercase tags, and escape literal parentheses (\( \)).
• Always add detail - even to an already-tagged prompt. NoobAI has no aggressive aesthetic baked in, so push toward roughly 8-15 caption-order items: subject count (1girl / 1boy / 1other), character / series, appearance, pose, scene, and lighting that the prompt leaves unstated, staying faithful to the stated subject.
• Mine any background context you were given (a scene/continuity note, recent conversation) for that extra detail and fold it in as depictable tags. Treat it as source material to pick from, not a checklist to dump and not a subject that overrides the explicit prompt; ignore chatter with no visual bearing.
• Build on the baseline negative and always keep the anti-furry block (mammal, anthro, furry, ambiguous form, feral, semi-anthro) unless the user actually wants furry / anthro art. If the positive opts into sensitive / nsfw, drop safe from the positive and nsfw from the negative together.

Worked examples

These illustrate the shape of a finished prompt - adapt them to the actual request, do not reuse them verbatim. Pass the prompt (and negative) value as a single string.

Standard portrait:

prompt:   masterpiece, best quality, newest, absurdres, highres, safe, very awa,
          1girl, solo, fern \(sousou no frieren\), sousou no frieren, artist:wlop,
          long purple hair, purple eyes, black coat, holding staff, magical sparks,
          forest clearing at dusk, cinematic lighting, soft glow, looking at viewer
negative: nsfw, worst quality, worst aesthetic, old, early, low quality, lowres, signature,
          username, logo, bad hands, mutated hands, mammal, anthro, furry, ambiguous form,
          feral, semi-anthro, text, watermark

Multi-artist style mix:

prompt:   masterpiece, best quality, newest, absurdres, highres, safe,
          artist:john_kafka, artist:nixeu, artist:quasarcake,
          1girl, chromatic aberration, film grain, horror \(theme\), limited palette,
          x-shaped pupils, high contrast, cold colors, black theme, gritty, graphite \(medium\)
negative: nsfw, worst quality, old, early, low quality, lowres, signature, username, logo,
          bad hands, mutated hands, mammal, anthro, furry, ambiguous form, feral, semi-anthro

The wrapped lines above are a single comma/space-joined string each - pass them as one line in the tool args.

Anti-patterns

• Treating v-pred like eps. CFG 7, DPM++ 2M Karras, no zsnr -> mushy, washed-out, or noise-laden output. Verify the workflow before blaming the prompt.
• CFG above 5. Specific to v-pred: extra CFG does not improve fidelity, it burns colors.
• Wrong sampler. Per the README, only Euler works properly. DPM++, UniPC, Heun all degrade output.
• Skipping the anti-furry block. Without mammal, anthro, furry, ambiguous form, feral, semi-anthro in the negative, e621 features leak into anime prompts (snouts, fur textures, paw pads).
• @-prefixed artists. Wrong here - use artist:name instead.
• Three-word prompts. NoobAI has no aggressive aesthetic tuning, so terse prompts come out bland. Always include the quality prefix + caption-order tags.
• Dropping safe without nsfw in the positive. Output drifts toward suggestive by default; either keep the safe/nsfw negative pairing, or explicitly opt in with sensitive / nsfw / explicit in the positive.
• Year + period both pointing different eras. Don't write year 2023, old - pick one.
• Square-bracket weighting. ComfyUI weights with parentheses - (tag:1.3) to strengthen, (tag:0.8) to weaken. A1111-style square brackets do not de-emphasize here: [tag] parses as ([tag]:1) (literal brackets at weight 1). Use (tag:0.8) to weaken instead.