Katechon ArcWhy characters drift
Each clip from a video model is a fresh generation. If the only description of a character is text in the prompt, the model reinterprets it every time: hair, age, wardrobe and face shift a little per shot and a lot per episode. The fix is to give the model the same visual evidence every time.
1. Make one reference per character
In Arc, characters, locations, props and products are assets with their own reference images. Generate the reference once, iterate on it with image editing until it is right, and treat it as the source of truth. Every shot that features the character attaches that reference.
2. Write the look into the project, not each prompt
Set the visual style and the cinematography brief at project level. They apply to every subsequent generation, so lighting and lens choices stay coherent and you stop restating them shot by shot.
3. Lock locations as well as faces
A character in an inconsistent room still reads as a continuity error. Give recurring locations their own references and reuse them in every scene set there.
4. Check the storyboard before the video
Storyboard frames show whether the right references landed in the right shots. Fix drift on the frame, where a regeneration is cheap, rather than on the clip.
5. Regenerate shots, not episodes
AI results still vary. When one shot drifts, regenerate that shot alone; the rest of the episode keeps its approved takes.
Checklist
- Every speaking character has an approved reference image.
- Every recurring location has a reference.
- Style and cinematography briefs are set at project level.
- Storyboard frames reviewed for the right faces and places before video.
- Drifted shots regenerated individually.
See the short drama workflow for where these steps fit in a series, and the answers on keeping locations consistent and costumes and props for the failures we hit in our own films.