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Claude Animated Shorts: cartoon story shorts rendered in code

A free Claude skill renders 55 to 70 second vertical cartoon shorts with three.js and Remotion, no AI video generator, and passed 1,200 stars in three days

74 soldiers cross the 1831 Broughton bridge in step until it drops, as in the 67 s short, while a playhead runs down the 15 shots of story.ts.
74 soldiers cross the 1831 Broughton bridge in step until it drops, as in the 67 s short, while a playhead runs down the 15 shots of story.ts.
Who
mromidev published the skill from the video "How to Make Viral Animated Shorts Using Claude", for people who make story shorts.
When
The first commit landed on 1 November 2026, with the reference contact sheets the same day. No release tags.
Where
A Claude Code skill copied to ~/.claude/skills/cartoon-3d-short/; renders on your PC with Remotion, Node, Python 3 and ffmpeg.

What was hard

Making a story short with an AI video generator meant prompting every scene, accepting a character who looked different in every cut, and rerolling until a cut came out right. At one minute that is about fifteen cuts, which was the work itself.

What it does about it

This skill renders the film in code instead of generating it. A 3D town with painted textures and ink outlines is built in three.js, flat 2D character cards stand in it, and Remotion renders the frames. The characters are therefore identical in every cut, and camera and timing are numbers in story.ts you can edit. Measured reports on 20 reference shorts come with it, so that channel's look is matched by measurement.

mromidev/claude-animated-shorts

How it runs inside

  1. 1

    You → Claude Code

    "Use the cartoon short skill and make a short about …"The README's one sentence. Given a topic, the agent follows SKILL.md in the skill folder.README.md
  2. 2

    Claude Code → cartoon-3d-short

    Facts → script → voice.wav + words.jsonOne true story and an analogy become a 55–70 s script: hook, escalation, snap, explanation, twist; then the voice.SKILL.md
  3. 3

    cartoon-3d-short → story.ts

    Copy templates/bridge, write SHOTS, CAMS, KICKS15 shots' frame ranges, light, camera keys, kicks and blur; each reaction lands 0–3 frames before its word.templates/bridge/story.ts
  4. 4

    story.ts → Remotion + three.js

    Assembles the three.js world and 2D cardsworld.ts builds sky, river, town and bridge each frame; cast.ts cards stand as billboards; ink.ts draws the lines.templates/bridge/world.ts
  5. 5

    Claude Code → Remotion + three.js

    Stills side by side with reference framesbridge-stills.mjs renders chosen frames, sbs_sheet.py pairs them with references; colour, ink and depth get scored.templates/scripts/bridge-stills.mjs
  6. 6

    Remotion + three.js → video.mp4

    2K render, synthesized mix, QAnpx remotion render at 1440x2560; mix.py blends voice, march and SFX to -15 LUFS; short_qa.py checks every frame.templates/audio/mix.py

What goes in, what comes out

"The 1831 Broughton bridge that fell to marching"the 67 s vertical short The Bridge That Fell for a Song
one script line in SCRIPT_example.mda cut, a camera kick and a sound effect timed to words.json

Is it for you

Good for

  • History or science stories as vertical shorts when you dislike the unevenness of generated video
  • A series where characters and world must stay the same in every cut
  • You already use Remotion and prefer camera and timing as code

Not for

  • You need a Remotion project with @remotion/three plus Node, Python 3 and ffmpeg; it is not an app that runs after a copy
  • Every bundle copies 1.3 GB of public/ into the temp folder; the README says to point REMOTION_TMP at a big drive
  • A 2K render runs at about 4 fps, about 10 minutes for 67 s per SKILL.md; the stills script points at a Windows Chrome path (from the code)
  • Reference frames are for style study only; story, characters and voice must be your own, and no voice tool is prescribed

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