Genjutsu tutorial: swap a character in an AI video
verified on 9 October 2026 · 3 min
Genjutsu can replace a video character using a visual reference. Choose the transformation, identify the person to replace and check the face, background and audio in the result.
Disclosure: some links in this tutorial are affiliate links. I may receive a commission if you subscribe through them. The examples and limitations come from our documented experiments.
Your reference images will now help replace a person in a clip. Genjutsu takes the source video and the intended character appearance. We use Glen's tiny car as an example. Start with a short replacement whose face, clothes and movement you can check.
For the first attempt, choose a scene with one clearly visible person. It will be easier to check whether the generator replaced the intended person. Move to scenes with several people once that first check is clear.
The method: approve an output at every stage
| Stage | What you prepare | When to move on |
|---|---|---|
| Video | One short Genjutsu clip | Target, clothes, duration and other people have been checked |
Object Swap or Motion Transfer?
Object Swap targets an element, such as the character you want to replace. Motion Transfer uses movement to reconstruct a scene around new references. These operations do not promise that every background detail, garment or movement will remain identical. This chapter focuses on swapping a character.
Prepare the source and reference
Use a short clip. Start with one visible person and a simple camera movement. Prepare the approved portrait and full-body sheet from the character chapter. The current public interface describes source videos of 4 to 30 seconds. The accepted limits can differ by workflow and interface, so check the screen you are using.
Start the replacement in Codex
Open your Codex conversation with the Higgsfield plugin connected. Describe the task in plain language and attach the files so the assistant uses the intended clip and sheet.
- Attach the source clip and only the approved character sheet.
- Request a Genjutsu character replacement using Object Swap. Identify the person by clothes and position, then explain what should remain.
- Ask Codex to show the settings and credit estimate. Generate one test and compare it with the source before trying again.
A useful instruction is: “Replace the person in the red shirt at the centre with my reference character. Keep the action and camera framing. Preserve the other people.” Treat this as a starting point, not a guarantee that all details will survive.
Compare the result with the source
Glen in the tiny car | YouTube
English captions, original video.
Glen’s tiny-car output lasts 6.375 seconds at 720 × 1280. The source was about 6.6 seconds. We restored the original audio and checked the ending. For the aeroplane scene, the full-body reference mattered because the pose exposed the clothing and shoes.
Check the face at the beginning, middle and end, then watch the fast movements. Inspect hands, shoes, clothes, background and other people. In the kitchen scene, identify the intended person precisely because several people are present.
Sound, corrections and credits
Listen to the exported file and compare its duration with the source. Do not assume that retained-looking footage includes the correct sound. A later text-removal or extension step may use another model and change resolution or timing.
Our October estimates included 49 credits for the tiny-car swap, 77 for the aeroplane and 91 for the two-person car scene. They are request estimates, not current universal prices or confirmed net spending. Keep room for retries and fix the most important defect first.