Module f-persona · Video · 8 min

Persona persistence
across frames.

Keeping a character's face, costume, and lighting consistent across hundreds of frames.

Reading time8 min Audio- Prerequisitesf-video-diff, 18 SourceTrack A · Gemini
§ 1

What this lesson covers.

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§ 2

The lesson itself.

Interactive lesson · ported from Gemini track Click tabs to navigate · hover cards for details
Video · Identity

Persona Persistence Across Frames

Keeping a character consistent · cross-clip identity · the AI Idol problem

THE PERSONA PROBLEM

Each generation forgets

An AI music idol or a brand mascot needs to look the same in every video. The model has no memory of "this is my character" between generations. Naive text prompts ("a woman with red hair, green eyes, freckles") drift — her face changes from clip to clip, her freckles disappear, her hair turns auburn. Persona persistence is the engineering problem of locking identity across hundreds of frames and dozens of generations.
VISUAL DNA

A persona is structured data, not a prompt

Treat the persona as a versioned record: face descriptors (eye color, jaw shape, freckle pattern), wardrobe rules, lighting preferences, posture defaults. Store as JSON. Every generation pulls from the same record. This is what separates a real character from a generated face — without it, every shoot starts at zero.
REFERENCE INJECTION

IP-Adapter + LoRA + DreamBooth, all at once

For maximum persistence: train a DreamBooth on 100+ shots of the persona (one-time), train a LoRA on the persona's specific lighting/aesthetic (recurring), and use IP-Adapter at inference with 3-5 reference frames pulled from the persona's library. The three techniques compound: DreamBooth locks the face shape, LoRA captures the look, IP-Adapter handles per-shot variations.
CROSS-CLIP CONSISTENCY

Same persona, different shots, same identity

For multi-shot videos: render all shots in one batch with the same seed offset, use the same persona reference, and post-process with a face-consistency model that detects drift and re-conditions. Practical heuristic: if you can't tell the persona is the same across two random frames, audiences won't either — reshoot.
§ PAPERS

Further reading.

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