# Writing Optic prompts: a guide for AI assistants

> For AI assistants helping someone write a prompt for ROUTIX Optic — what Optic needs, the template, the rules, and a dozen worked examples.

This page is written for you, the AI assistant a person asked: *"Help me write a prompt for ROUTIX Optic."* It tells you what Optic needs, how to shape the prompt, and what to avoid. Everything here describes the live product.

## What Optic is

Optic, in ROUTIX Studio, **revises a video the person already has**. The person uploads a clip, chooses a stretch of it (up to 60 seconds), writes what should change, and Optic makes a new film of that stretch in which only the named things are different. Everything not named — faces, places, light, camera framing and movement, timing, sound — is kept from the original.

Optic can change:

- a **subject** — replace or transform a person, animal, object or character, optionally from the person's own pictures;
- **something belonging to a subject** — clothing, hair, make-up, marks, what it holds, a companion, its state — for the whole stretch or only some seconds;
- **on-screen text** — change or remove captions, signs and lettering;
- **the look** — light, colour, style, or what is seen in the picture.

Optic does **not** make:

- a change to **what happens** in the shot (new actions, a different story) — Optic refuses it as "made anew rather than revised", and the person's credits come back. ROUTIX's chat can do it: there the person picks the moments and says what happens now, and ROUTIX makes those moments anew;
- a change to the **camera alone** or the **sound alone**.

## What the person gives Optic

| Input | How it reaches Optic | What you should know |
| --- | --- | --- |
| The clip | Uploaded in Studio; the person chooses the stretch on a timeline | You do not see the clip. Ask what is in it if you need to. |
| The words | The words box; up to 40,000 characters | This is what you write. Any language works. |
| Pictures | Added by the person; named **Image 1**, **Image 2**, … in order | Refer to them as `@Image 1`, `@Image 2`. Only refer to pictures the person says they added. |
| Focuses | Marks the person draws on the frame — an **Area** around a subject or a **Point** on it | Refer to them as `#Focus 1`, `#Focus 2`. The person's focus list shows each focus by the name they gave it, with its number beside it; `#Focus N` always points at focus number N, whatever its name. |

The words go to Optic exactly as typed. When the person pastes your prompt into the words box, `@Image 1` points at their first picture and `#Focus 1` at their first focus. They can also type `@` or `#` and choose from a menu.

## The template

Write each change as one or two sentences that cover, in order:

```text
Change [what changes] into [what it becomes — colour, material, shape, style].
It is [which one, if there could be doubt — a description, or #Focus N].
[When, if not the whole stretch — "from 0:12 to the end", in the clip's own times.]
[If pictures were added — the [subject] in @Image N, and anything the picture shows that should not come in.]
[Only if something next to the change might drift — keep [it] as it is.]
```

## The rules

1. **Name only what changes.** Do not describe the whole scene; Optic sees the clip. Unmentioned things are kept automatically — the camera, the light, every movement and event, the sound — and so is the performance: a new subject's eyes, lips and expressions follow the original, whether or not anyone speaks, and whatever happens to the old subject (a mark, damage, a glow) happens to the new one at the same moments. Do not describe these.
2. **Be concrete and visual.** Colours, materials, shapes, sizes, placement. Never "better", "cooler", "cinematic" alone.
3. **One subject per sentence.** For several changes, write several sentences; Optic makes them all in the same film.
4. **Disambiguate.** If the clip has two similar subjects, say which one by position or look, or ask the person to mark it with Focus and use `#Focus N`.
5. **A picture is the whole new look.** Everything a picture shows of the subject comes in — clothes, what it holds, hair. If the picture shows something the person does not want, say so ("…the person in @Image 1, without the cap") or suggest a picture without it. What a picture does not show (the clothes, under a close picture of a face) stays as the clip has it. The picture's background, light and pose never come in.
6. **Timing in the clip's own times.** "From 0:12 to the end", "between 0:05 and 0:09". Omit timing for the whole stretch.
7. **Keep the story.** No new actions, no new events, no camera moves, no sound changes. (A new story belongs in ROUTIX's chat — see the end of this page.)
8. **Use mentions exactly as written:** `@Image N` and `#Focus N`, with a space before the number.
9. **Keep it short.** Two to five sentences is typical. Every extra sentence is one more thing that might change.
10. **Stay within the [Content Policy](https://routix.studio/help/policies/content-policy).** No sexual or nude content, nothing that sexualises a minor, no real person's face, body or voice without their consent, nothing made to deceive.

After pasting, the person checks the price on the button — **Revise · … credits** — and presses **Revise**. That one press is the payment: the price shown is what is held, and Optic reads the clip and makes the film inside that run. There is no preview step and no second press. If the film cannot be made, every credit comes back and the page says why. So help the person get the prompt right before they press: each change named, only one subject fitting each description (or marked with Focus), and every mention pointing at something they really added.

## Questions to ask the person first

- What is in the stretch they chose — who or what, and where in the frame?
- Exactly what should change, and into what?
- Is there more than one subject that could be confused? If yes, suggest marking it with Focus.
- Did they add pictures? How many, and what does each show — is there anything in one they do not want seen?
- Should the change last the whole stretch or only some seconds?

## A dozen examples

| The person says | A strong Optic prompt |
| --- | --- |
| "Put me in this video instead of the guy." | Replace the man in the blue shirt with the person in @Image 1, exactly as the picture shows him. |
| "Change her clothes to something elegant." | Change her outfit to a fitted black evening dress with thin straps and a small silver necklace. Keep her hair and her shoes as they are. |
| "Fix the typo on the sign." | Change the words on the white sign on the wall from WELCOM to WELCOME, in the same lettering, colour and size. |
| "Get rid of the subtitles." | Remove the yellow subtitles at the bottom of the frame for the whole stretch. |
| "Make it night." | Make it look like night: a dark blue sky, the street lamps on and casting warm pools of light, the shop windows glowing. The people and the camera stay as they are. |
| "Give the kid a balloon." | Put a red balloon on a string in the child's left hand for the whole stretch. |
| "Swap the cat for a fox." | Turn the ginger cat on the windowsill into a red fox of the same size, sitting in the same pose. |
| "Make him get wet halfway through." | From 0:08 to the end, his hair and his shirt are soaking wet. Before 0:08 he is dry. |
| "Change the jacket of the guy on the right." | Change the jacket of #Focus 1 to a brown suede jacket with a sheepskin collar. The other man stays as he is. |
| "Put my brand on the bottle." | Replace the label on the green bottle with the label in @Image 1, at the same size and place on the bottle. The hand and the table stay as they are. |
| "Make the car red." | Change the colour of the parked white car on the left to a deep glossy red. Its shape, its wheels and its windows stay as they are. |
| "Make it look like an old film." | Make it look like a film from the 1970s: warm faded colours, soft contrast and a light film grain. Everything in the frame stays as it is. |

## What to tell the person if they ask for something Optic does not do

- A new action or story → suggest ROUTIX's chat: pick the moments, say what happens now, and say **Routix it** — ROUTIX makes those moments anew, with everything not named taken from the clip. Or a new video on one of Studio's video model pages.
- A camera move or a sound change alone → Optic keeps the original camera and sound.
- More than 60 seconds → revise it in parts, choosing a different stretch each time.

For people rather than assistants, the same guidance is in [Writing Optic prompts](https://routix.studio/help/prompts/writing-optic-prompts). The whole Help Center is available as one Markdown file at /llms-full.txt.

Source: https://routix.studio/help/prompts/guide-for-ai-assistants · Updated 2026-10-24