How to Keep Characters Consistent in AI Video (Stop the Drift)

Character drift is the single biggest tell that a video was made with AI: the same person's face shifts between shots, an outfit changes colour, the lighting jumps, and a sequence that should feel like one scene reads as a pile of unrelated clips. It's the most-asked-about problem in AI video for a reason — and the fix is almost never where people look for it.

You don't stop drift at render time. You stop it upstream, by locking what every shot shares before you generate any of them. This guide explains why drift happens and the five techniques that actually hold a character across a whole piece.

Why characters drift

A text-to-video model turns words into a clip, and "a woman with red hair in a leather jacket" describes a category, not a person. Generate that prompt twice and you get two different women who both match the words. Every new shot is a fresh roll of the dice, so faces, wardrobe, and grade wander.

Drift compounds when you generate shots independently — one prompt at a time, in isolation. There's no shared anchor, so there's nothing for the model to stay consistent to. Fix that, and most of the problem disappears.

Lock the look before you generate

The single highest-leverage move is to establish your foundations first — and treat them as the source of truth every shot inherits:

• One character reference. A single locked image (or a tight set) that defines exactly what your person looks like — not a description, an actual frame.
• One style. The grade, film stock, palette, and lighting, fixed and applied to every shot.
• One voice, if anyone speaks — the same voice per character for the whole piece.

Lock these once, approve them, and only then build shots on top. This is the difference between "a character" and "the same character." For product or brand work, the same discipline applies — see AI product photography for locking a product's exact look.

Five techniques that actually hold a character

1. Start from a locked reference image

Generate the character as a still first, get the face exactly right, and reuse that frame as the anchor for every shot. An image is far easier to control precisely than a moving clip — Nano Banana is built for holding an identity across stills.

2. Use image-to-video, not text-to-video, for identity

Any shot where the person has to be them should start from that locked still and animate it (image-to-video), not from a fresh text prompt. Text-to-video is for establishing shots where identity doesn't matter; image-to-video is for everything that does.

3. Fix one style and never re-roll it

A consistent grade does as much for "this is one scene" as a consistent face. Decide the look once and carry it across every shot rather than letting each generation pick its own.

4. Prefer native multi-shot over many separate clips

Generating several shots in one pass keeps the subject, lighting, and style consistent across them by construction. For cohesive sequences, Seedance and Kling can produce multiple shots natively — far more consistent than stitching a dozen independent clips.

5. Use start-and-end keyframes for controlled motion

When you need a specific move, give the model the first and last frame and let it interpolate between them. You control both ends, so the character can't wander mid-shot. In Bucksy this runs on Kling by default.

Kling 3.0

How Bucksy keeps characters consistent

Bucksy is built around this exact discipline. It establishes the foundations — character, style, and a single locked voice per character — and pauses to confirm the look with you before it spends time building every shot on top of it. Approve the foundation, and the whole piece is consistent by construction. For identity-critical shots it starts from the locked reference and animates it; for cohesive sequences it defaults to native multi-shot segments instead of a dozen disconnected clips. You don't manage references across five apps — there's one source of truth, and the agent holds it.

For the full pipeline this fits into, read how to make AI videos end to end.

Frequently asked questions

Why does my AI character look different in every shot? Because each shot was generated from a text prompt with no shared anchor. A description matches many people; lock one reference image and animate that instead.

Which AI models keep characters most consistent? The ones that let you start from an image and generate multiple shots in one pass — Kling and Seedance for video, Nano Banana for the reference stills.

Can I fix drift after generating? It's far harder than preventing it. Re-rolling shots to "match" wastes time; locking the foundations up front is the real fix.

Do I have to do this manually? No. Describe the piece and let Bucksy lock the character and style, confirm the look with you, then build every shot on that single source of truth.