# Reel engine

The system that makes octyn's reels. A script and one voice take go in; a finished pixel-art reel comes out, and every part of it, from the character to the edit, is Python and Blender scripts.

Domain: Our own · Reel engine
Label: Running (our own)

## Dated figures

- Two reels made: 33.6 s in 33 shots, 26.7 s in 19 shots (recorded 2026-10-03)
- 13 sets, 5 gaits, 18 gestures (recorded 2026-10-03)
- 1080 x 1920 at 24 fps, loudness normalized to -14 LUFS (recorded 2026-10-03)

The reel engine is OCTYN's own system for making short reels of octyn, our mascot: a CRT for a head, a heather tee, cartoon gloves. The page at /casestudies/reel-engine shows it working. This is the written version.

## Every part is code

Nothing in a reel is drawn or keyframed by hand. The character and his skeleton, the sets and the props, every pose and every step, the renders, the pixel art, the screens, the effects, the sound and the edit are Python and Blender scripts in one repository. A script and a voice take go in; a finished 1080 x 1920 reel comes out.

## The situation

We wanted octyn in short reels, often and on script, without hand-drawing each one. The first build was a flat 2D cutout rig. On 2 Oct its proofs came back with eleven marked frames: an arm growing out of the torso, a glove like a fork, a hand hidden behind the phone, arms running straight into a laptop lid. Those came from the foundation, so octyn was rebuilt in Blender from the ground up, on a real skeleton, and drawn back into pixel art at the end. The marked frames became a written test that every clip has to pass.

## How it works

1. **Script.** A few short lines with one picture under them. Every topic and gag goes into a ledger and is never used again.
2. **Voice.** One continuous take, never chopped up, with a start and an end for every word. The picture is cut to those times.
3. **Lip sync.** Rhubarb writes mouth cues; they fold into four mouth levels for the face on his screen.
4. **Shot list.** Each shot is a line of Python whose start and end are words, so cuts land on what is said.
5. **Character, sets, props.** octyn is built from primitives on an armature. Thirteen sets, each one Python file. Props work: the cube's top layer turns, the kettle pours, the sign over the front desk takes any word.
6. **Pose, motion, contact.** Poses are written as where the wrist goes and which way the elbow points. A walk's step follows the ground covered, so feet never slide. Props are picked up by grip sites and set down where he leaves them. Contact runs last on every hand, so nothing goes into a surface.
7. **Render passes.** Cycles at 180 x 320, one sample. The pixel pass reads normals, depth, object and material per pixel.
8. **Pixel pass.** Three shades per material, a 1px line only where one part sits in front of another, the face drawn onto the glass in whole pixels, then scaled six times.
9. **Screens and effects.** Phone, laptop, sign and whiteboard screens are drawn as pixel art and mapped onto the glass in the scene.
10. **Edit and sound.** Shots go down on the voice's clock, captions come from the word times, the sound is synthesized from the render's own events, and the mix is normalized to -14 LUFS.

## What a reviewer caught, and what changed

The hard problems were the ones a person spotted in a frame. Which side a limb curves: the wrist is measured against the forearm with a real range, and an elbow never folds across his chest to keep a forearm off the lens. Hands inside objects: contact treats every object near a hand as a surface. A cup held round its body with the handle pointing away: cups now turn so the handle meets his hand. Each note became a rule in the code, so it does not come back.

## Where it stands

As of 3 Oct 2026 the engine has made two reels and a set of acting tests, and the reels are reviewed by a person before anything is posted.

## Related

- [The Consult](https://octyn.co/consult)

Canonical: https://octyn.co/casestudies/reel-engine