# S-21 Slide Brief V3

## Status

- Slide: `s21`
- Source shot: `S-21: 那一簇火，指引方向`
- Version: `s21-v3`
- Written by: `session-03` child session
- Worker profile: `video-slide-production`
- Running mode: `prompt and generate`
- Review: disabled
- Overwrite allowed: no

## Source Basis

- `projects/2026-06-23-在路上/intake/阶段五-人物一致性单镜.md`
- `projects/2026-06-23-在路上/visual-system/visual-system.md`
- `projects/2026-06-23-在路上/visual-system/style/style-prompt-master.md`
- `projects/2026-06-23-在路上/visual-system/characters/character-reference-registry.md`
- `projects/2026-06-23-在路上/slides/broad-generation-self-audit-v1.md`
- `investigations/2026-06-24-s14-reference-capable-generation/reviews/summary-and-rule-implications.md`

## Slide Function

Validate side/back dynamic character consistency for the traveler while introducing the first fire as a direction signal.

The fire does not let him stop. It confirms that he can continue walking.

## First Read

Night road and muddy roadside first, then a small restrained fire, then the traveler at the edge of the firelight adjusting the old backpack and continuing forward.

## Risk Class

`medium human / side-back dynamic consistency`

Risk reason:

- The traveler is visible enough for coat, backpack, stride, boots, and side/back posture to matter.
- Text-only identity prompting is not sufficient.
- The prior broad-run `s21-v1-image.png` lacked prompt/reference trace and had posture risk.

## Reference Plan

Style:

- Style module: `D | 夜路小火`
- Active style reference: `projects/2026-06-23-在路上/intake/imgs/D.夜路篝火型蓝图.png`
- Role: restrained night-road fire style, small fire signal, mood/palette guardrail

Character:

- Primary character reference: `projects/2026-06-23-在路上/visual-system/characters/character-anchor-v2-walk-side-reference-crop-tight.png`
- Role: `Image 1: identity reference for side/back walking traveler adjusting backpack`
- Supporting character reference if the slide-agent can load a second visible image: `projects/2026-06-23-在路上/visual-system/characters/character-slice-walk-side-v2-from-anchor.png`
- Supporting role: walking side silhouette, coat length, backpack placement, stride, and boots

The actual character reference image must be loaded into visible generation context before host image generation. A local file path in the prompt is traceability only and does not count as loading the image.

## Visual Requirements

- 16:9 horizontal cinematic documentary road-film still.
- Deep blue-gray night or post-dusk roadside.
- Small real fire near the roadside, preferably to one side or lower part of the frame.
- Muddy road continues beyond the fire.
- Firelight touches mud, boots, backpack edge, or coat edge, but does not flood the whole frame.
- Traveler is side/back to camera, not front-facing, not looking at the viewer.
- Traveler is adjusting the old backpack naturally, as if preparing to continue.
- Person scale: about `1/6` to `1/4` of frame.
- Fire scale: small directional signal, not large campfire.

## Character Handling

Keep these from the active character system:

- middle-aged road-worn male traveler around 50;
- dark slightly messy hair where visible;
- dark gray / dark khaki / coal-black long coat;
- old practical backpack;
- worn boots;
- tired but capable body posture.

Do not replace the active image reference with a text-only character description. If the reference image cannot be made visible to generation context, block generation and write the reason in the return.

## Composition / Scale

- Environment first, road second, fire third, traveler fourth.
- The traveler may be on the edge of the firelight, not centered as a portrait.
- The action should orient toward the road, not toward staying by the fire.
- Leave dark road/depth ahead of the traveler.

## Light / Color / Texture

- Base: cold wet blue-gray, dark khaki, coal black, earth brown.
- Emotional accent: restrained warm orange firelight.
- Texture: real mud, wet road, rough stones, worn fabric, backpack straps.
- Keep dark depth in the background.

## Forbidden Drift

- No camping advertisement.
- No tent, chairs, cookware, picnic setup, cozy campsite, group gathering, reunion, or victory.
- No large theatrical bonfire.
- No portrait MV, hero pose, fashion travel photography, or motivational poster.
- No text, labels, logos, watermarks, UI, or sci-fi/neon drift.
- No text-only identity generation for the visible traveler.

## Acceptance Checklist

- The traveler can plausibly be the same person as the active character references.
- Side/back posture, old backpack, long coat, stride, and boots remain stable.
- The adjustment of the backpack looks natural rather than posed.
- The fire is small and directional, not a destination.
- The image reads as "continue forward" rather than "rest at camp."
- The prompt records `gpt-image-2` Advisor use and the visible-context image role.
- No `s21-v3-review.md` is written.

## Prompt Handoff

`Agent S-21` must read this brief and write only:

- `projects/2026-06-23-在路上/slides/s21/s21-v3-prompt.md`
- `projects/2026-06-23-在路上/slides/s21/s21-v3-image.png`
- `projects/2026-06-23-在路上/tasks/2026-06-24-character-consistency/session-03/returns/s21-v3-slide-agent-return.md`

The prompt must use the `gpt-image-2` Skill Advisor / host-native workflow, assign the loaded character reference as `Image 1`, use style module `D | 夜路小火`, and suppress review.