The same hooded figure held inside three offset frames of light in a dark room

Character Consistency

How to Keep a Character Consistent in Grok Imagine

A character drifts because every generation is a fresh render. The model is not remembering your last clip; it is reading the current prompt and references from scratch. Consistency is therefore a systems problem, not a magic prompt. This guide gives you the small system that keeps a face, outfit, and presence recognizable from shot to shot.

Updated 2026-10-19Jump to FAQ

Why characters drift

Text-to-video has no memory. Even image-to-video re-renders the source frame with new motion, and small changes in light or pose can cascade into a different face. The more the prompt changes between shots, the more the model has to invent.

Reference images reduce the search space, but they do not eliminate it. You still need a stable description, a clean set of angles, and a shot plan that does not ask the model to solve identity and action at the same time.

The core rule: Keep identity constant and change one production variable at a time — camera, action, or light. If all three move, you will not know which one broke the character.

Write a five-line character bible

The bible is a short block you paste into every prompt. It should be specific enough to constrain the render and short enough that it does not crowd out the action.

LineWhat to writeExample

FaceAge, face shape, one distinctive featureLate 20s, narrow face, faint scar above left brow

HairLength, texture, colour, stylingShoulder-length dark hair, loose waves, side part

WardrobeTwo or three stable garmentsCharcoal field jacket, black tee, worn leather strap

SignatureOne object or detail that repeatsA brass compass on the right hip

PresencePosture and emotional temperatureStill posture, guarded expression, deliberate movement

A dark reference board linking one portrait frame to three other frames with threads of light — A character bible turns memory into a repeatable set of words and images.

Build a reference set that answers questions

The studio accepts up to 9 image references in one generation. Use the slots to cover different questions, not to upload nine nearly identical selfies.

One clean front view with even light for the face.
One three-quarter view to establish the nose and cheek structure.
One profile if the character turns during the sequence.
One full-body frame for proportions and wardrobe.
One detail frame for the signature object or texture.
One expression frame if the performance depends on a specific mood.

Use an anchor frame, then vary one thing

An anchor frame is the one image you trust most. Start every shot from it, or from a render that preserves it, and change only the motion description. This is especially effective for image-to-video, where the starting composition already fixes much of the identity.

If you need a new angle, generate a still from the character bible first. Approve the face before you ask for motion. A good still is cheaper to iterate than a bad video.

Lock the stillGenerate or select one portrait that matches the bible. Keep the source file and the exact prompt that produced it.
Write the motion onlyFor image-to-video, describe what moves, how the camera behaves, and the pace. Do not re-describe the face; the source already carries it.
Test three shotsGenerate a wide, a medium, and a close shot with the same bible and reference set. Compare identity before expanding to a full sequence.
Keep the best takeSave the strongest clip as the new anchor. Do not keep remixing every shot from scratch just because one detail is off.

Anchor the identity first, then let the camera and action vary around it.

The three-shot test

A character that survives one clip can still fall apart in a sequence. Run a small test before you spend credits on the full piece.

ShotWhat it testsPass condition

WideSilhouette, wardrobe, and proportionThe character reads as the same person at a distance

MediumFace shape and hairlineThe same features survive a new angle

CloseEyes, skin, and signature detailThe detail is recognizable without the original frame

When the character still changes

Fix the most local cause first. Most drift comes from a prompt that reintroduces identity, a reference set with contradictory lighting, or a camera move that spends too much time away from the face.

Remove redundant face descriptions from motion prompts; they can overwrite the reference.
Replace a reference whose light or age contradicts the others.
Keep the subject centred for the first second, then move the camera.
Use a shorter clip for close-ups; long, complex motion gives identity more chances to drift.
For voice, supply a clean audio reference up to 15 seconds and ask for the same delivery, rather than naming a real person.

Frequently asked questions

How many reference images can I use for one character?+

Up to 9 image references per generation. Use a mix of front, three-quarter, profile, full-body, and detail shots rather than duplicates.

Why does the face change between clips?+

Each generation is a fresh render. A changed prompt, different light, or a new camera angle can shift identity unless the reference set and character bible stay constant.

Can I keep the same voice too?+

The studio accepts up to 3 audio references with 15 seconds total. A clean voice clip is the practical way to keep delivery close; do not rely on naming a real person.

Should I use text-to-video or image-to-video for consistency?+

Image-to-video is usually more stable because the starting frame fixes composition and identity. Use text-to-video to design the character, then move to image-to-video for the shots.

Can I fix a character after the video is generated?+

Not with a timeline retouch here. Regenerate from the anchor frame with a narrower change, or finish the correction in an external editor.

Is a consistent character guaranteed?+

No. References and a character bible improve the odds substantially, but every render is still an interpretation. Test the three-shot set before committing to a long sequence.

Related guides

Build the Character Once

Design the still, keep the bible short, and test three angles before you generate the full sequence.

See Plans