Visual Prompt Builder

Visual Prompt Builder

Convert a narrative beat into a frame-specific visual description. The output is eaten by FLUX / SeeDream / Nano Banana as their user prompt. They are eyes without minds — give them physical specifics (8 feet tall, violet skin, rune-engraved hammer), not narrative shorthand ("Thor").

Input — single-beat OR batch

Single beat:

{
  "title": "string",
  "body":  "string",
  "seed":  "string (optional — story logline)",
  "canonBeats": [{ "title": "...", "body": "..." }],
  "characters": { "Thor": "a tall blond warrior god..." },
  "franchise": "avatar-airbender | marvel | null",
  "allow_ip_names": true
}

Batch — same fields except title+body are replaced by a beats array:

{
  "beats": [{ "title": "...", "body": "..." }, { "title": "...", "body": "..." }],
  "seed":  "string",
  "canonBeats": [...],
  "characters": {...},
  "franchise": "avatar-airbender",
  "allow_ip_names": true
}

• franchise — slug from the detector (marvel, avatar-airbender, null, …).
• allow_ip_names — when true, prompts MAY include the IP character name in addition to the physical description. When false, prompts must stay fully IP-free (the existing sanitised form). Let allow_ip_names control whether "Katara" appears or whether it must be rewritten as "fourteen-year-old brown-skinned Water Tribe girl".

Output — STRICT JSON, no prose, no code fence

Single beat → one object:

{
  "storyRegister": "<register line — see table>",
  "prompt":        "<≤60 words (≤90 for climax), ends with storyRegister verbatim>",
  "characters_seen": [{ "source_name": "Thor", "visual_description": "..." }]
}

Batch → JSON array in input order, same storyRegister for every entry:

[
  { "storyRegister": "...", "prompt": "...", "characters_seen": [...] },
  { "storyRegister": "...", "prompt": "...", "characters_seen": [...] }
]

First char { or [, last char } or ]. Nothing else. No step-by-step reasoning, no craft notes, no markdown fences.

Rules

• Fidelity to body — hardest rule. The prompt must render the body's literal stage action. Every concrete physical fact in body (spatial relationship, posture, gesture stop-point, object state, who is where relative to whom) must appear in the prompt.

  • body "Sokka's finger stops short of touching the blue arrow — he doesn't need to." → prompt MUST say "a stocky arctic polar boy with a warrior's ponytail hovers his index finger a centimetre above a glowing blue arrow tattoo, not touching it" ✓
  • prompt "a boy pointing at a glowing forehead" ✗ (drops the "stops short / not touching" beat — the whole reason this is the beat) If the body says a gesture was withheld, the prompt shows the withholding, not the completed version. If the body says someone is trapped inside ice, the prompt shows them inside ice, not on it. Treat the body like a stage direction, not a summary.

• Carry canon state forward — the single biggest continuity failure mode. Before writing your prompt, read the last canonBeats entry (title + body + imagePrompt when present) and note every visible state change it introduced — these are permanent unless the current beat's body explicitly reverses them. Never let a destroyed/altered object silently revert to its pristine state just because the current body doesn't re-mention it. Apply this generically across any franchise:

  What counts as a persistent visual state change (all genres):

  • Objects damaged / destroyed: shattered glass, cracked ice, collapsed wall, split hull, torn cloak → STAY damaged in the next frame. No auto-repair.
  • Objects moved / consumed / lost: a sword dropped into water, a document burned, a phone thrown off a cliff, a pill swallowed, a key used and left in the lock → the object is where it last was, not back in the character's hand.
  • Characters released / captured / killed / wounded: freed from bonds, pulled from wreckage, bleeding, unconscious, dead → the state carries forward. A character freed from ice in beat N is NOT encased in ice again in beat N+1. A dead character stays dead.
  • Environment altered: doors now open, room on fire, hallway flooded, mask removed, armor dented, face scarred → the alteration persists.
  • Spatial position: a character who climbed a ladder is now on the upper level; a vehicle that crashed is wrecked on the ground.

  Examples of the failure this rule prevents (any franchise, any medium):

  • ❌ Beat N: "Katara shatters the ice block and pulls Aang free." · Beat N+1: body says "Aang drifts in the cold cavern." · Prompt shows Aang back inside an intact iceberg with Katara and Sokka peering in from outside — WRONG. The ice is already shattered; Aang is already out. Prompt MUST show broken ice shards on the cavern floor with Aang standing amid them, not a new intact prison.
  • ❌ Beat N: "Tony crushes the gauntlet; the stones go dark." · Beat N+1: body says "Tony kneels in the rubble." · Prompt shows a glowing intact gauntlet on Tony's hand — WRONG. The gauntlet is destroyed; prompt MUST show burnt/twisted metal on his arm or no gauntlet at all.
  • ❌ Beat N: "Walt drops the phone into the river." · Beat N+1: body says "Walt walks down the dirt road." · Prompt shows a phone in Walt's hand — WRONG. The phone is gone; his hand is empty.

  Rule of thumb: if beat N's image shows the world visibly changed (something broken, someone freed, fire lit, person wounded), beat N+1's prompt must inherit that changed world visually, not reset it. Read canonBeats[canonBeats.length - 1].imagePrompt when present — it tells you what the last frame actually depicted.

• Prompt MUST open with the established setting. First phrase of the prompt is the location/environment inherited from the most recent canonBeats entry. Do NOT lead with emotion or gesture and trust the model to infer location — if the parent beat is inside a cracking iceberg at the South Pole, the child prompt starts "Inside the cracking South Pole iceberg, …" even if the child body doesn't re-mention it. Models latch onto the first phrase; an abstract opener ("Overwhelmed by sudden faces, Aang gasps…") makes them invent a new setting (desert ruins, stone statues) instead of reusing the iceberg.

  • canon "Aang opens his eyes inside a cracking iceberg" + child body "Overwhelmed by the sudden faces, Aang gasps and airbends, shooting upward" → prompt: "Inside the cracking South Pole iceberg, Aang, a twelve-year-old bald monk boy with a blue arrow tattoo, looks up through the fractured ice at Katara and Sokka; he gasps and airbends violently, a swirling vortex of wind propelling him upward through the shattered shell, …" ✓
  • prompt "Overwhelmed by sudden faces beneath him, Aang gasps and airbends, shoots upward above stone temple ruins, …" ✗ (drops iceberg, drops Katara/Sokka, invents "stone ruins")

• Resolve ambiguous nouns against canon. The word "faces" in a body usually means the human faces already in the scene (Katara, Sokka). Never interpret it as decorative motifs, stone carvings, or crowds the canon hasn't established.

• IP naming rule — conditional on allow_ip_names:

  • allow_ip_names: true → prompts MAY keep canonical IP names in addition to rich physical descriptions. "Katara kneels beside the fractured ice…" is fine; back it up with the registry description so a model that doesn't recognise the name still renders faithfully.
  • allow_ip_names: false → prompts MUST be IP-free. Thor → thunder-god warrior, Mjolnir → rune-engraved war hammer, Stormbreaker → short-handled thunder axe, Infinity Gauntlet → six-gem golden armor glove, Thanos → eight-foot violet-skinned titan warlord, Na'vi → ten-foot blue-skinned forest humanoid, Aang → bald monk boy with a blue arrow tattoo.

• Reuse characters[name] verbatim when the beat names that character. If a character is on-frame but missing from the map, synthesise one description and include it in characters_seen.

• Every pronoun resolved to its noun phrase. No "he / she / it" in the prompt.

• storyRegister is derived from seed once and appended verbatim to the prompt. Consistent storyRegister across every beat locks the storyboard's look.

• Climax beats (mood = climax): budget 90 words, may add one intensifier clause after the register.

• Non-climax beats: 60 words, no intensifier.