Character Prompt Library Method
Reuse detailed character definitions to preserve continuity across AI video clips
- Difficulty
- Easy
- Time to result
- ~days to results
- Steps
- 6
- Confidence
- 94%
Create a canonical text prompt for every recurring character before generating scenes. The prompt should capture stable visual and behavioral identifiers such as appearance, clothing, age, posture, voice, and distinctive traits. Store these definitions in a prompt library rather than rewriting them from memory. Whenever a character appears in a new scene, insert the same canonical description alongside the scene-specific action, setting, camera, and dialogue instructions. Generate the bounded clips, compare outputs for drift, and regenerate mismatched scenes before editing them into a longer sequence. This does not guarantee perfect continuity, but it gives the video model a repeated identity anchor. The method converts an unreliable series of isolated generations into a controlled production process with reusable character specifications.
Origin
Extracted from Marketing Against The Grain while Kieran explained how he joined multiple VO3 clips into a longer movie sequence.
Core principles
- 01Consistency requires a reusable source of character truth
- 02Every generated scene must receive the same defining details
- 03Characters should be designed once and instantiated repeatedly
- 04Clip assembly works better when continuity is planned upfront
How to run it
- 1
Design the character
Specify the recurring character's stable appearance, clothing, voice, manner, and distinguishing features.
Pro tip Favor concrete observable attributes over subjective adjectives.
Watch out Conflicting traits can create more variation rather than less.
- 2
Create the canonical prompt
Turn the stable specification into one reusable prompt block and preserve its wording.
Pro tip Assign each character a clear library name for quick reuse.
Watch out Do not casually rewrite the character block between scenes.
- 3
Add scene instructions
Combine the canonical character block with the new setting, action, dialogue, camera, and lighting requirements.
Pro tip Keep mutable scene details separate from immutable identity details.
Watch out Scene instructions that contradict the character specification can cause drift.
- 4
Generate bounded clips
Produce each scene as a short clip using the relevant canonical prompts.
Pro tip Generate difficult continuity transitions in several variants.
Watch out Assume separate generations may still differ despite identical prompts.
- 5
Check continuity
Compare faces, wardrobe, voice, proportions, and mannerisms across adjacent clips before editing.
Pro tip Regenerate inconsistent clips before investing in the final edit.
Watch out Small inconsistencies become more noticeable when clips are joined.
- 6
Assemble the sequence
Edit the accepted clips into a longer narrative and retain the library for future scenes.
Pro tip Record any prompt refinements as a new version rather than silently changing the original.
Watch out Do not mix prompt versions within one continuity sequence.
In the wild
A creator defines the movie's recurring characters as detailed prompt blocks, adds the relevant block whenever a character appears, generates multiple eight-second scenes, and edits the accepted clips into a 24-second sequence while working toward a longer mini-movie.
→ The recurring characters remain more recognizable across independently generated scenes.
Common mistakes
Rewriting characters per scene
Small wording changes can lead the model to reinterpret the character rather than reproduce it.
Mixing identity and action
When permanent traits and scene-specific instructions are not separated, later edits can accidentally alter the character.
Skipping continuity review
Editing clips together before checking them can lock obvious visual drift into the sequence.
Is it for you?
Best for
It is best for creators making multi-scene AI videos with recurring fictional characters.
Not ideal for
It is not ideal for one-shot clips, abstract footage, or productions requiring exact actor-level continuity.
From the transcript
“But like you have to actually build character prompts.”
“So I build a detailed character prompt, and then every time you create a new video, you insert the character prompts.”
“So you can build basically a prompt library of characters who appear in the movie.”
From the episode
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