Text Flash Cuts — our demo

One example among many. Don't reuse its story, arc, shots, props or timings.

Demo: Behind You (身後, 46.2 s) · text-flash-cuts.mp4 · source in demo/

A trailer for a fictional suspense series. Everything in it is invented: the title, the two characters, every line and the "series" itself; no existing anime, character, line or card text is used. Cold open: a red card, "別回頭。" ("Don't look back."). Four chapters follow, and in each one the girl who said it comes one step closer to the boy: a letter (written), a phone call (a voice, while she walks up behind him in the rain), a wall of windows (her face in every pane), the stairs (her back at the top). On the thirteenth step she is the one who looks back: "輪到你了。" ("Your turn.").

Story & structure

Shape: a four-chapter trailer whose single line is distance closing. Hook (0–0.7 s): a one-point tunnel bursts and three single-glyph cards cut in at six frames each, spelling the first line before it is shown whole. Setup (0.7–4.8 s): the whole line on a red rail beside a symmetric staircase with a tiny back-turned figure at the top; then her back in colour at the right edge, her head starting to turn, cut away before we see her face. Chapters (4.8–35.2 s), each opened by its own chapter card and each bringing a new space, a new way for her to be near and a new move: 信 (a locker in a wall of lockers, the letter, "誰寫的？"), 雨 (a one-point street, a phone, a split-screen call in which her figure jumps closer once per beat, a hand on his shoulder, the empty street with her umbrella on the ground), 窗 (a window wall, then nine panes of her face that all tilt their heads at once), 階 (the climb, a count of 十, 十一, 十二 in ever-shorter cuts, her back at the top, "再上一級。"). Ending (35.2–46.2 s): "十三", 1.2 s of silence with two clock ticks, the head tilt, her line, her eye with his reflection, the corner of her mouth, the title.

Why it fits the style: the medium has no lip-sync and no narrator, so the dialogue lives on two coloured rails (his black on the left, hers red on the right) that hold while the picture beside them keeps cutting. The flash cards only ever fragment words that are held in full somewhere else. Native moves spent: flash cards, speaker rails, chapter cards (four layouts), symbolic architecture (stairs, lockers, street, window wall, tunnels), the stepping approach, fragment inserts (eyes, a hand, a letter, a mouth), multi-panel faces with a group head tilt, count-up acceleration, red-black inversion, extreme offset and absolute symmetry, and the signature head tilt as the ending.

Shots

30 fps; cuts are on a 150 BPM grid (12 frames a beat). Times in seconds.

Reading: every held line is checked by readcheck.mjs (the shortest margin is "你到底是誰？", 2.68 s for 2.68 s needed). Flash cards and chapter cards are not reported to the check by design; each word they flash is also held in full.

Score structure

• 150 BPM, 4/4, D minor (i–VI–iv–V per bar: Dm, B♭, Gm, A). Instruments (samples, CC0): harpsichord, contrabass and cello pizzicato, violins pizzicato and tremolo, bowed vibraphone, glockenspiel, woodblock, timpani, gran cassa, snare, trombone, tuba, horn, tubular bells, tam-tam, suspended cymbal. No piano, no string pad.
• Arc: card hits and a tunnel rush (0–0.7) → contrabass D + cello E♭ under the stairs, the woodblock clock on every beat (0.8–3.2) → two harpsichord notes under her back → chapter 1: tubular bell, then the harpsichord ostinato in 16ths with pizzicato bass and the clock → chapter 2: the ostinato drops out; tremolo violins at a whisper, bowed vibraphone, rain, a wet footstep per beat getting louder (15.8–18.2) → hard silence 18.40–18.60 → sting (high cluster, bass drum, cymbal scrape) on the hand → chapter 3: her glockenspiel lullaby (A–D–F–E–D–A), the ostinato in 8ths, one glockenspiel note per pane, low brass stab on the group tilt → chapter 4: ostinato back in 16ths, timpani rising one step per beat (F2 → E3), brass stabs on 十 / 十一 / 十二 (Dm, E♭, E), snare accelerating 30.6–32.2, a low brass pedal under "再上一級" → timpani and bass drum on 十三 → silence 35.05–36.37 (only two clock ticks, 35.4 and 36.0) → reversed swell → the tilt: neck crack + tam-tam + low brass D–A–D–F–E♭ (Dm♭9) + low strings → heartbeat and glockenspiel fragments under the eye and the mouth → end card: tubular bell D, timpani, tam-tam, glockenspiel D–F–A–D.
• Hits per card, pitched up as tension rises (×1 → 1.12 → 1.26 … → 2.1).
• J-cuts: rain before the 雨 card; the phone buzz before the phone; the clock ticks before the tilt. L-cuts: the tam-tam into the eye; the rain under the umbrella.
• Mix: limited before mux.sh, −14 LUFS integrated. No voice: the cards are the dialogue.

Beat / action table (seconds):

Palette & props

• Red #d4162b, black #0a0a0c, paper white #f2efe8, grey #8d8a84 (English only); #d8d4cc, #26262a, #1b1b1f inside geometry.
• Her: black high-collar long coat, a blunt black bob, a small red rectangular clip, red eyes. Him: black high-collar school uniform, messy black hair, grey eyes. Their rails: hers red with black type (right), his black with white type (left).
• Props, all code: a locker wall with numbered doors, a phone, a fallen umbrella, window walls, stairs with red handrails, lamps.

Title card

Black, left-aligned, held 5.0 s: "身後" (Noto Serif SC 900, 300 px) with a small red clip mark, "BEHIND YOU", the line "有些問題，回頭才有答案。" / "Some answers wait behind you.", a thin rule, "文字閃切 Text Flash Cuts", "LemoLab × Claude Opus 5.5", "Samples: Versilian Studios (CC0)". A red bar descends on the right with her small white silhouette beneath it. The "LemoLab × Claude Opus 5.5" sign-off belongs to this library's demo only; a user's film carries no LemoLab credit and no copy of this card.

Build notes

demo/
  index.html          page: fonts, render(t) / TEXTS(t) / EV
  main.js             the film: SH timeline (frames), FLIPS, EV, every shot function, rail(), the head-tilt rig
  mix.py              score (sampler) + procedural sound, reads events.json
  tools/prep.py       keys the chroma-green images, pulls generated reds to #d4162b
  tools/key.py        keys and crops char_lookback (rig coordinates are in that crop)
  tools/fonts.sh      font subsets built from every non-ASCII character in main.js
  tools/gen_all.sh    draws the images from prompts/prompts.json through core/image/gen_image.py (not called by build.sh)
  gen/                the 11 images (Codex image generation; local, not in git)      prompts/   prompts and --ref chain

1. sh demo/build.sh (library set up with setup.sh deps music): fonts → assets → events → reading check → render (1,386 frames, 30 fps) → mix → mux (−14 LUFS, grain 0) → poster and styleframe (38.3 s). Workers default to 2 (WORKERS=4 sh demo/build.sh to change). On a fresh clone build.sh fetches the two sample libraries itself (sh tools/fetch.sh instruments vsco2ce and … vcsl) and fetches the font subsets from Google Fonts; the 11 images in demo/gen/ are not in git, so a clone cannot rebuild this film as it is (build.sh stops and says so): sh demo/tools/gen_all.sh draws a new set through core/image/gen_image.py (it needs the Codex CLI), and the rig is then re-measured.
2. Rig coordinates: PIVOT, HEADPOLY, COLLAR (char_lookback, cropped coordinates), HB (her back view), HF (face points for the nine panes). Re-measure them if an image is regenerated.
3. Pitfalls tied to this demo: a held line needs the shot under it to last its reading time (her line on the call shot needs 3.0 s, not 2.5 s); keep the chapter on the beat grid by taking the difference from a neighbouring architecture shot. A figure in a long street must be large enough to read as a person (here about twice the first size). A low angle on a figure at the top crops at the calves, never the head. A window wall keeps its grid while panes go dark: dark panes stay inside white mullions and go out slowly.
4. Images: the 11 pictures are Codex image generation made for this story (CREDITS). A film on another topic generates its own characters and inserts from its own model sheets (STYLE.md §9); the demo's images are never reused.