Low-poly Isometric Island — our demo

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

Demo: The Island That Grew (53 s) · lowpoly-island.mp4 · source in demo/

Story & structure

An empty sea with only a buoy that knows one note; tiles, trees and houses rise from the sea one by one, each landing with a note, so the island and its song are written together — until at night the boat that went out cannot find its way home, and the last "note" is a lighthouse.

The film's shape: a small world that grows, lives through a day, and meets one problem that the final piece solves — one subject (an island), one goal (to become a home), one turn (night falls, the boat is lost). It is only this film's shape, not the way to adapt any topic.

Emotional arc (53 s): emptiness → first note → accelerating joy of building → a lived-in day → dusk warmth → silent night with one thing missing → the final piece ignites (climax) → pull back to scale, with an echo of the opening.

Native powers spent: procedural growth (the whole first act), the orthographic gaze (the final ×25 zoom), turntable (the growth shot), flat shading × light (the day time-lapse), emissive blocks (windows at dusk, the beam at night).

"Building is composing", as the demo paid it off: every growth event is exported from the page with a MIDI note, and the score's melody voice is synthesized from those events. The lighthouse beam turns once every 12 beats and passes one ring cell per beat; the eight houses standing on those cells light up and chime as it passes, so the notes laid down in a shuffled build order are replayed in spatial order as the complete theme. The second ring around the centre cell has 12 cells at exactly 30° steps, which makes this beat-synced sweep possible.

Shots

Camera settings used: azimuth 45° by default, elevation 30° (build), 33–35° (day detail), 20–25° (night — a lower angle widens the sky band so stars show), 50° (top-down-ish when the beam sweeps). Frustum height 5–7 for close-ups, 12–16 for the whole island, up to 420 for the final scale reveal.

Score structure

• Event-driven: page EV entries carry note; music/score.py synthesizes every one at its exact time (rise → marimba, pop → kalimba, floor → woodblock, roof → kalimba+marimba = the melody, window → soft kalimba, ring → rising marimba, beamhit → kalimba lead + marimba octave + bell shimmer). Underneath: ambient pad, a gentle marimba ostinato and shaker/soft kick only in the day and climax sections. 96 BPM, D major pentatonic feel. No piano, no strings.
• One note as a motif: a buoy bell on D5 opens the film ("the only note the sea knows") and a distant bell plays the same note at the end.
• Silence: the night section drops to a low pad drone, waves and crickets; the music bus is digital zero for the last half-beat before the climax downbeat.
• Growth scheduled on the 16th grid: tiles on halves → quarters → eighths.
• The boat's answering bell sits in a rest of the melody, filling the gap when the beam finds it.
• Foley (mix.py): as in STYLE.md §7, plus gulls by day (downward-gliding FM chirps), windmill creak, crickets from dusk; the dock plank knock and lighthouse-ring stone thunk, glass tink for the lamp room, whump + hum on ignition. Floors: second knock 0.21 s after the first.
• Voice: Kokoro af_sky (clear, gentle female), speed 0.86–0.92, 5 short lines. "Sea" is heard as "C" in a film about notes, so the narration says "ocean".
• Mix: voice compressed, ~10 dB over the music; music ducked −8 dB under the voice; −14 LUFS; grain 0.

Palette & props

• Terrain heights: sand 0.36–0.42, grass 0.74–0.9, hills 1.1–1.4, rock peak 1.95; top cap 0.16 thick, side column sunk 0.1 below it; 1.5 % gap between tiles; lightness jitter ±4 %; roughness .88.
• Props: box houses 0.92 wide, 0.62 per floor, gable roof prism (overhang 0.08) with wall-coloured gable ends; windows = small quads with their own emissive material per house; cone pines (6 sides), icosahedron (detail 0) broadleaf trees, 3-sided-cone palm fronds; windmill (6-sided tapered tower, 4 blades); dock planks on posts; a boat from a pinched box hull + triangle sail; lighthouse = 4 tapered 8-sided rings alternating white/red + dark gallery + emissive glass + red cone cap. Three gulls circle; chimney smoke; the windmill spins up on the "island complete" chord.
• Palette (sRGB): sand top #f3dfab / side #e2c68e; grass #93c96c, #7fbd62; earth side #c99c6e; rock #b4b8bd / #8f949c; walls #fbf3e6 #f5c2b0 #b5dccb #a9cbe8 #f7df8f #e9c9e6; roofs #d9644a #4f7fb8 #e0874f #6a5a8e #3f8f86; pines #3f8a5a #4f9c63; leaves #7fc36a #9ad06f; warm windows #ffc676; lighthouse #f6f2ea / #d9544a.
• Day/night keyframes (zenith / horizon / deep sea / shallow / sun): dawn #9fb6cf / #f3d2c4 / #4f8ea3 / #8fc9c4; day #88c8e8 / #eaf5f2 / #38a5bc / #86e2d4 sun 2.7; dusk #6f6fa8 / #ffa888 / #5a6a9e / #b08aa6 sun #ff9a68 elevation 8°; night #12163a / #4a4478 / #23264a / #363a66, moon #a9b0e8 0.9. Night sea darker near the camera and brightening toward the sky band.
• Sea: 220×220 plane, 200×200 segments, four summed sines (amplitude ≈ 0.2), roughness 0.55; coarse 5000-unit plane 0.55 below; lagoon map a 512² canvas of soft blobs where tiles have risen; surf ring 0.99–1.12 r, opacity ≈ 0.32.
• Arrival numbers: rise 0.5 s cubic ease, overshoot sin(13 s)·e^(−7 s)·0.18, hex splash ring + 14 droplets 0.12 s before it settles. Drop: 2.4 units in 0.22 s (ease-in), bounce |sin(15 s)|·e^(−9 s)·0.22, squash 1 − 0.16·e^(−12 s)·cos(26 s) on Y, volume preserved. Pop: 1 − e^(−9 s)·cos(17 s).
• Post: GTAO radius 0.7, scale 1.5; tilt-shift max radius 3 px at the frame edges; bloom threshold 0.95, strength 0.22 day / 0.5 night; grade sat 1.04–1.1, soft contrast, small blue lift at night; render 3840×2160.
• Lighthouse beam: camera-facing ribbon, halo 2.4× wider at 0.32 strength, tilted 7° down so it meets the sea far away; water lit by an angular band around the beam direction plus per-facet sparkles. Beam: one turn every 12 beats.
• Subtitles as built: Quicksand 600, 44 px, #fffdf8, navy drop shadow (blur 14), centred 118 px above the bottom; the hex icon (top + two side faces) is dawn pink, day grass, dusk orange, night window-yellow. Shown from 0.05 s before the line.
• Title: Josefin Sans 600, all caps, 78 px, 16 px tracking; letters rise 55 ms apart from under a thin water line; 300-weight lowercase sub-line ("a low-poly island film").

End card

The night scale-reveal frame, darkened; the same title block (static), hex icon, LOW-POLY ISLAND · LEMO-OPUSCAR, LemoLab × Claude Opus 5.5, credits, laid out so the tiny lit island stays visible in a gap between the text blocks. The "LemoLab × Claude Opus 5.5" sign-off (and the LEMO-OPUSCAR line) belongs to this library's demo only; a user's film carries no LemoLab credit and no copy of this card.

Build notes

styles/lowpoly-island/demo/
  story.js   timeline (96 BPM grid), VO, chords, day/night keyframes, shots
  world.js   hex layout, all props, growth schedule → EV (with notes), per-frame animation
  sea.js     faceted wave shader, shallow-lagoon map, beam-lit water
  post.js    ortho post: GTAO → sky/haze + stars → tilt-shift → bloom → grade
  main.js    renderer, lights, cameras per shot, HUD (title, subtitles, end card), EV export
  music/score.py   event-driven score (+ check.py: librosa onset/pitch check vs events)
  mix.py     foley + ambience + voice + ducking     subs.py  subtitle cues
  build.sh   one-command rebuild

1. node core/render/still.mjs styles/lowpoly-island/demo --range 0.5:52.5:1 + core/render/sheet.py — overview sheets, iterate.
2. core/tts/tts.py lines.json voices → core/tts/asr_check.py until all OK.
3. node core/render/events.mjs styles/lowpoly-island/demo → music/score.py → music/check.py → mix.py.
4. node core/render/video.mjs styles/lowpoly-island/demo --fps 24 --workers 3 (1272 frames, 2× SSAA + GTAO).
5. sh core/render/mux.sh out/video24.mp4 mix.wav lowpoly-island.mp4 24 0. Or just sh demo/build.sh.

Pitfalls tied to this demo's props:

• An invisible glow sprite becomes a black parallelogram floating on the sea in the GTAO pass.
• Derive the boat's position from the beam's angular speed so the beam finds it on a chosen beat, in frame (a rest in the melody, so the boat's answering bell fills the gap): at 21 units out it is off-screen when the beam finds it.
• Don't let the sea receive shadows: at low sun they make a long dark stain.