spark-video-cast

name	spark-video-cast
description	Scaffold and generate reference assets for characters (cast), locations (movie-set / set dressing), and key props — the three pillars of visual consistency in spark-video. Wraps bl image generate / edit for cast reference sheet creation. Use when adding new characters/locations/props or when costume/state changes are needed.

Cast / Set / Prop Skill — spark-video Art Department (all-in-one)

You are the art department of the pipeline. Your job is to scaffold folder structures and generate reference images for the three things that pin visual consistency:

Pillar	Pins	Folder pattern
Cast	Full-body reference sheet: face, hairstyle, costume, build	cast/<name>/
Movie-set	Locations, lighting, decor	movie-set/<name>/
Prop	Hero objects that recur or change state	props/<name>/

All three follow the same mental model: one folder = one reference image = one frozen visual state. State changes (day→night, intact→torn, casual→formal) = separate folders.

Set env vars:

export SPARK_VIDEO_PROJECT=<project_id>
export SPARK_VIDEO_EPISODE=<NN>
export SPARK_VIDEO_PHASE=cast-reference

Two-tier model — project vs episode

Both cast, set, and prop live under two tiers. Episode tier overrides project tier on name collision:

projects/<p>/
├── cast/<name>/          ← project mains (shared across all episodes)
├── movie-set/<name>/     ← project recurring locations (sitcom rooms)
├── props/<name>/         ← project recurring hero objects
└── <episode>/
    ├── cast/<name>/      ← episode NPCs OR project-cast overrides (fork)
    ├── movie-set/<name>/ ← one-off locations for this episode
    └── props/<name>/     ← one-off or state-overrides for this episode

Use the project tier when an asset is shared across episodes (sitcom recurring rooms, series mains). Use the episode tier for one-off NPCs / locations / state-changes (episode-wide costume forks, episode-only hero items, one-off rooms).

⚠ THE ONE-FOLDER-ONE-STATE RULE (hard rule, applies to all 3)

The video model reads reference images literally. Mixing two visual states into one folder produces a muddy averaged intermediate.

Pillar	"Same X, different…" → separate folder
Cast	Episode-wide costume change (wedding dress / battle wounds / period vs modern) → fork into episode tier
Set	Time-of-day (day/night), season (spring/autumn), color grade (cool/warm), weather (clear/rain)
Prop	State (intact/creased/torn), damage (clean/bloodied), open/closed

Naming convention: <base_name>-<discriminator>:

• 同福客栈大堂-白天 / 同福客栈大堂-夜晚
• 红包-完整 / 红包-起皱 / 红包-撕碎
• 陆辰-汉服 (forked from 陆辰 for one episode)

Procedure 1 — scaffold a cast

Cast reference image contract

Generated cast images should be character reference sheets, not single photoreal portraits. Seedance-style providers are less likely to reject an obviously synthetic character sheet than a realistic headshot.

Every cast-image generation prompt MUST include this intent:

a three-view drawing of a person and annotate it with an AI-generated, non-real-person watermark on the bottom

Make the sheet show the same character in front / side / back views, with consistent face, hair, costume, build, and a plain background. The bottom annotation is part of the image content for safety provenance; do not use provider watermark flags. Avoid any other readable text.

1.1 Lead / project-tier character

# Scaffold the folder + soul card template
uv run scripts/scaffold.py cast --name "陆辰"
# Edit projects/<p>/cast/陆辰/cast.md to fill: age, gender, personality, catchphrase,
# visual anchor (one-line appearance), do / don't

Then generate the cast reference sheet via bl. Default to a full-body standing character sheet / 三视图 rather than a face-only or front-only portrait. Keep the portrait filename prefix for compatibility with the rest of the pipeline:

./scripts/bl image generate \
  --model wan2.6-t2i \
  --prompt "a three-view drawing of a person and annotate it with an AI-generated, non-real-person watermark on the bottom, 28-year-old man, short hair, dark T-shirt, full-body character reference sheet, front view, side view, back view, same face and costume in all views, plain background, no other readable text, $(uv run scripts/scaffold.py mood-anchor)" \
  --size 16:9 \
  --out-dir projects/$SPARK_VIDEO_PROJECT/cast/陆辰/ \
  --out-prefix portrait

Notes:

• Default model wan2.6-t2i: produces stable cast reference sheets compatible with downstream r2v. qwen-image-2.0 is newer but visual style differs; test before switching.
• Append lore.mood_anchor to every cast-reference prompt so the visual style matches the rest of the production. The scaffold.py mood-anchor helper prints lore's mood_anchor for piping.
• Prefer generated / hand-drawn character sheets over real-person photos for providers with input privacy checks. If you drop a real actor reference into the folder, make sure you have the right to use it and that your target provider accepts real-person inputs; it overrides the generated reference sheet at r2v time.

Optional: voice reference for reference-voice r2v (Wan / bl both support):

• Drop a 5–10s clean speech sample as voice.mp3 in the cast folder.

1.2 NPC (episode-only)

uv run scripts/scaffold.py cast --name "钱夫人" --episode
# → projects/<p>/<ep>/cast/钱夫人/

./scripts/bl image generate \
  --model wan2.6-t2i \
  --prompt "a three-view drawing of a person and annotate it with an AI-generated, non-real-person watermark on the bottom, middle-aged woman, stout build, dark silk hanfu, gold hairpin, shrewd worldly expression, full-body character reference sheet, front view, side view, back view, same face and costume in all views, plain background, no other readable text, $(uv run scripts/scaffold.py mood-anchor)" \
  --size 16:9 \
  --out-dir projects/$SPARK_VIDEO_PROJECT/episode-$SPARK_VIDEO_EPISODE/cast/钱夫人/ \
  --out-prefix portrait

Then re-init the merged cast.json:

uv run scripts/scaffold.py cast-init   # merges project + episode tiers

1.3 Cast fork — episode-wide costume change

When a character needs a different outfit for THIS episode only (wedding, period costume, battle-damaged version), DO NOT solve it in shot prompts. Fork the cast reference:

# Deep-copy the project cast folder into the episode, drop old reference images
uv run scripts/scaffold.py cast --fork --name "陆辰" --drop-portraits

# Regenerate the reference sheet with the new appearance
./scripts/bl image edit \
  --image projects/$SPARK_VIDEO_PROJECT/cast/陆辰/portrait1.png \
  --prompt "Create a three-view drawing of the same person and annotate it with an AI-generated, non-real-person watermark on the bottom. Change the character's outfit to a large red traditional Chinese wedding robe and red wedding cap; keep face and hairstyle unchanged. Output a full-body character reference sheet with front view, side view, back view, same face and costume in all views, plain background, no other readable text, $(uv run scripts/scaffold.py mood-anchor)" \
  --out-dir projects/$SPARK_VIDEO_PROJECT/episode-$SPARK_VIDEO_EPISODE/cast/陆辰/ \
  --out-prefix portrait

uv run scripts/scaffold.py cast-init

bl image edit preserves face identity better than bl image generate for forks — always prefer edit when you have a project-tier reference sheet or portrait to base from.

For pixel-perfect face identity (edit can still drift slightly), drop a hand-edited PNG / three-view sheet into the episode cast folder instead of using bl.

Procedure 2 — scaffold a movie-set

2.1 When to scaffold a set

Scaffold whenever:

• Two or more shots happen in the same location with the same lighting.
• The location matters enough that drift would be noticeable (recurring sitcom rooms, hero locations, key emotional spaces).
• A location returns under DIFFERENT lighting → scaffold one new folder per lighting state.

Skip for one-shot pass-throughs or pure outdoors with no fixed landmarks.

2.2 Naming — lighting state in the folder name

Same physical place, different…	Action
Time-of-day (day / dusk / night / pre-dawn)	Separate folders (客栈大堂-白天, 客栈大堂-夜晚)
Season (spring / summer / autumn / winter)	Separate if visible (willows / snow / red leaves)
Color grade (memory cold gray / present warm yellow / high-contrast neon)	Separate folders
Weather (clear / rain / snow / fog)	Separate when weather is in frame
Decor unchanged, action just moves around the room	Same folder

2.3 Scaffold + generate

# Project-tier sitcom recurring room
uv run scripts/scaffold.py set --name "同福客栈大堂-白天"

# Episode-tier one-off
uv run scripts/scaffold.py set --name "出租屋客厅-暖灯" --episode

# Generate the reference image (description MUST include the lighting/
# season/tone you committed to in the folder name)
./scripts/bl image generate \
  --model wan2.6-t2i \
  --prompt "Ming-Qing style wooden inn lobby, two-story wooden staircase, red lanterns, three square tables, daytime natural light through windows, warm yellow tone, $(uv run scripts/scaffold.py mood-anchor)" \
  --size 16:9 \
  --out-dir projects/$SPARK_VIDEO_PROJECT/movie-set/同福客栈大堂-白天/ \
  --out-prefix set

# Rebuild movie_set.json
uv run scripts/scaffold.py set-init

The set.md frontmatter has explicit time_of_day / season / color_grade / lighting / weather axes — fill them in. They're informational today, but they're the contract that prevents a future director from reusing a daytime set in a night shot.

Procedure 3 — scaffold a prop

3.1 When to promote an object to a key prop

Promote any object to a key prop when it satisfies either:

• It appears in 2+ shots and the audience would notice if it changed shape/material/color/wear (the red envelope in S01-003 → S01-007 → S04-002).
• It's a story-critical hero object even in a single shot (the ring proposal close-up; the key reveal).

Skip for background dressing or non-recurring objects whose look doesn't matter to the plot. Budget: 3–6 named props per episode, more is a smell.

3.2 Scaffold + generate

# Project-tier recurring prop (family heirloom)
uv run scripts/scaffold.py prop --name "戒指-完整"

# Episode-tier one-off or state-change
uv run scripts/scaffold.py prop --name "红包-起皱" --episode

# Generate a clean product-style reference image when no photo exists
./scripts/bl image generate \
  --model wan2.6-t2i \
  --prompt "Standard Chinese red envelope, large red hot-stamped pattern, printed with '囍', flat with no creases, pure white background, product photography style, $(uv run scripts/scaffold.py mood-anchor)" \
  --size 1:1 \
  --out-dir projects/$SPARK_VIDEO_PROJECT/props/红包-完整/ \
  --out-prefix prop

# State change — produce creased state as a separate folder + image
./scripts/bl image edit \
  --image projects/$SPARK_VIDEO_PROJECT/props/红包-完整/prop1.png \
  --prompt "Add obvious creases and grip-worn folds to the red envelope; keep color, print, and shape exactly unchanged" \
  --out-dir projects/$SPARK_VIDEO_PROJECT/episode-$SPARK_VIDEO_EPISODE/props/红包-起皱/ \
  --out-prefix prop

# Rebuild props.json
uv run scripts/scaffold.py prop-init

For state changes, always prefer bl image edit with the base state image as input — preserves shape/print/material continuity. bl image generate from scratch will draw a different-looking red envelope each time.

Generation tips (apply to all three)

Mood anchor — append it to every t2i prompt

# Helper that prints lore's mood_anchor for piping:
uv run scripts/scaffold.py mood-anchor

Without it, your asset visual style won't match the rendered shots.

Aspect ratio defaults

Asset type	--size
Cast reference sheet (full-body three-view, default)	16:9
Legacy single cast portrait (only when provider accepts it)	3:4 or 9:16
Set establishing	16:9
Prop (product-style)	1:1

Batch generation in parallel

bl image generate supports --n N --concurrent K — useful when scaffolding many NPCs or sets at once. Each --n produces a candidate; keep the best, delete the rest.

./scripts/bl image generate --n 3 --concurrent 3 \
  --model wan2.6-t2i \
  --prompt "..." \
  --out-dir projects/.../cast/陆辰/ \
  --out-prefix candidate
# → candidate1.png, candidate2.png, candidate3.png; rename winner to portrait1.png

Multi-image merge (cast fork only)

bl image edit accepts multiple --image flags. Useful when forking a cast with a costume reference photo:

./scripts/bl image edit \
  --image cast/陆辰/portrait1.png \
  --image refs/hanfu-reference.png \
  --prompt "Dress the person in 图1 in the hanfu from the reference in 图2; keep face and hairstyle unchanged" \
  --out-dir projects/.../episode-X/cast/陆辰/

After scaffolding — rebuild manifests

The merged manifests (cast.json, movie_set.json, props.json) must be rebuilt after any folder change. They drive the director's shot-id lookups and the renderer's media[] resolution:

uv run scripts/scaffold.py cast-init
uv run scripts/scaffold.py set-init
uv run scripts/scaffold.py prop-init
# or all three:
uv run scripts/scaffold.py manifests

Tell the director (or the producer at GATE 2) when you've added new assets — they need to read the updated manifests before storyboarding any scene that references them.

DON'Ts

• ❌ Don't put two lighting states (day + night) in the same set folder. The model averages and produces "neutral gray noon-night" garbage.
• ❌ Don't put two prop states (intact + creased) in the same prop folder. Same reason.
• ❌ Don't solve a costume change by writing "wearing XXX" in shot prompts. Fork the cast reference sheet instead.
• ❌ Don't omit the mood_anchor in t2i prompts. Visual cohesion will break across shots vs cast references.
• ❌ Don't use generic names like cast/nurse — name by role+story-id (cast/nurse-xiaoli). When two episodes both have a "nurse", you can't tell whose cast reference is whose.
• ❌ Don't use provider / CLI watermark flags such as --watermark. For generated cast sheets, ask for the bottom provenance annotation in the prompt itself: AI-generated, non-real-person. Keep it outside the character body and avoid any other readable text.
• ❌ Don't skip scaffold.py *-init after adding folders. The manifests are the only thing the rest of the pipeline reads.