From a One-Line Idea to a Narrated AI Short Film

By Kevin Yi

Most AI short films fail before any picture is generated. The idea is fine; nobody turned it into a story with a shape. You get a few pretty shots and a mood board instead of a film.

This guide walks one idea through logline, beat sheet, narration, look, pacing and the choice of which shots move. The example is a narrated short with no on-screen dialogue: a narrator carries the story, and the pictures support the words.

Step 1: Turn the idea into a logline

Our starting idea: a lighthouse keeper on a remote island.

That is a setting, not a story. A logline adds three things: who, what they want, and what stands in the way. A useful template:

When [event], a [specific character] must [goal] before [stakes].

Our version:

When the last ship stops answering her signals, an elderly lighthouse keeper must keep the light burning through one final storm, even though no one has told her whether anyone is still out there.

Now you know what every scene is for. If a shot doesn’t serve the keeper, the light, the storm or the unanswered question, it can go. If you can say the logline in one breath, you’re ready.

Step 2: Build a beat sheet sized to your running time

A beat is one change in the story. For a one- to two-minute short, six to eight beats is plenty. Write them as plain sentences, one line each, before you write a word of narration.

#	Beat	Rough length
1	Dawn. The keeper climbs the stairs, as she has for forty years.	10 s
2	The radio is silent. No ship has answered in weeks.	10 s
3	A storm builds on the horizon.	10 s
4	The lamp fails. She repairs it by hand, in the dark.	15 s
5	The light returns. She sweeps it across the black water.	10 s
6	Far out, a tiny light flashes back.	10 s
7	Morning. Calm sea. She writes one line in the logbook.	10 s

That is roughly 75 seconds. Notice the shape: setup (1–2), rising trouble (3–4), turn (5–6), release (7). Even a short film needs a turn. Here it is beat 6, the answering light.

Step 3: Write screenplay-style narration, not dialogue

Since the film is narrated, think of the narration as the screenplay. Each beat gets two or three short sentences. Write for the ear: concrete nouns, present tense, one idea per sentence.

Beat 2, first draft:

She had been waiting for a response from the shipping company for several weeks, and it was becoming increasingly likely that the route had been discontinued.

Rewritten for narration:

The radio stays quiet. Three weeks now. Maybe the ships take another route. Maybe there are no ships at all.

It’s shorter, easier to say aloud, and leaves room for the picture.

A few rules that keep narration tight:

Describe what we can’t see. The picture already shows the stairs; the narration can say forty years.
Never narrate what a character says. “She told the radio…” invites the viewer to expect speech that won’t come. Narrate thoughts and actions instead.
Read it aloud with a timer. Many narrators land somewhere around 130–150 words a minute. If beat 4 runs 40 seconds out loud, it is too long for a 15-second slot.

Total for our seven beats: about 170 words, a little over a minute when read at a calm pace.

Step 4: Choose a realistic or an animated look

This choice changes how the audience reads the whole film, so make it before anything is drawn.

Realistic looks suit drama, sci-fi, horror and documentary-style history. They also make small inconsistencies more noticeable: a coat that changes colour between shots jumps out.

Animated looks (comic, watercolor, anime, 3D animated) suit fables, children’s stories and anything a little dreamlike. They forgive more, and they signal “this is a told story” from the first frame.

For the lighthouse film, a realistic look fits the quiet, grown-up tone; a watercolor version would turn it into a picture-book fable.

As a worked example, I’ll use an AI movie maker that plans the whole film from either a one-line pitch or a pasted screenplay. Its page lists a Realism default plus animated looks, a narrator in 17 languages, 16:9 or 9:16, and a running time from 15 seconds up to multi-minute films. Pasted text is narrated word for word, so the narration you wrote in Step 3 survives intact. It also shows each scene as a storyboard frame before anything is animated, which is the point where you catch problems cheaply.

Know its limits: one narrator tells the film and there are no camera-move controls (you edit a scene’s prompt or redraw it). If one beat needs a character speaking on screen, render that shot as a separate lip-synced clip on a model that supports it and cut it in. If your whole idea depends on two actors arguing in close-up, a shot-by-shot director tool fits better.

Step 5: Fix the cast before the first scene

Our film has one character, which is ideal for a first short: every extra main character is another face that has to stay the same.

Decide her look once, in one line, and reuse it: a woman in her seventies, short grey hair, navy wool coat, yellow oilskin hat. If your tool lets you attach a reference picture (a sketch, a character sheet), do it before generating scenes; the movie maker above accepts up to five of your own pictures and can design up to three main characters, then reuses each one in every shot. Approve the character first, then the scenes.

Step 6: Pace the scenes

Match picture changes to sentence breaks.

One beat, one main picture. If a beat runs longer than about 15 seconds, split it into two shots. Animated shots in tools like this typically run 5 to 15 seconds each, so a long beat naturally becomes more shots.
Hold the quiet moments. Beat 7 (the logbook) works better as a still frame with a slow narration line than as a busy moving shot.
Change the scale. Alternate wide shots (the lighthouse in the storm) with close ones (her hands on the lamp).

Review every storyboard frame. If one drifts (wrong coat), redraw that frame alone.

Step 7: Decide which shots should move

Motion is usually the expensive part. On the movie maker used here, one minute of film is about 232 credits with still frames, or about 1,732 with every shot animated. Writing the script is free, every step shows its cost before you confirm, failed animations refund their credits automatically, and new accounts get 100 free credits with no card.

For the lighthouse film, I would animate three shots:

Beat 3, the storm rolling in: the moment the stakes rise.
Beat 5, the beam sweeping the water: the visual heart of the film.
Beat 6, the answering light: the turn.

Everything else holds as a still under the narration, which suits the lonely mood. A simple rule: animate the shot where something changes, keep still the shot where someone reflects.

Step 8: Cut a trailer

A 15- to 30-second trailer for Shorts, Reels or TikTok is often what people see first. Pull the strongest narration line (“Maybe there are no ships at all”), two or three animated shots and the logline as on-screen text. End on a question: don’t show the answering light.

If you’d rather brief it than edit it yourself, a separate tool such as ViewMax Studio can take a short brief through its agent mode and plan its own shot list, cuts, narration and music in one pass for a vertical teaser; it starts with free credits and shows the cost before you render. Either way, keep the trailer’s look matched to the film so viewers recognise it when they click through.

A one-screen checklist

Logline: who, wants what, against what.
Six to eight beats with a clear turn.
Narration timed aloud; no quoted dialogue.
Look chosen before anything is drawn.
Main character approved before scenes.
Drifted frames redrawn individually.
Motion spent where something changes.
A vertical trailer that ends on a question.

Start with one sentence. If it survives Step 1, the rest is craft.

Kevin Yi builds AI video tools, including ToonBee AI.