Cut-free motion master

MotionKit

Kit root: the folder this skill lives in, one level up (call it $KIT; if the skill was symlinked, resolve the link — e.g. ~/.claude/skills/motionkit → <clone>/skill, so $KIT = <clone>). It is distilled from 60 reference videos the user curated; follow it instead of generic motion defaults.

Non-negotiables (the user's standing preferences)

1. No sudden cuts. Every scene change is carried by something on both sides of the seam ($KIT/grammar/01-continuity.md). Max ⅓ of seams may be hard cuts, and only on a strong beat.
2. Liquid, fluid, rounded. Long-tail ease-outs, squash/stretch on contact, material changes before shape, blur as glue (02-motion-easing.md).
3. Never generate or synthesise music. Use the user's track. If none is given, ask for one. The kit ships no music.
4. Camera decided by content (rounds 3–4): plan a varied route (never the same direction twice in a row: trucks L/R, pedestals up/down, diagonals, pushes, pulls, holds) and alternate camera beats with element beats where polished elements interact under a still camera; sync events to the music (sync_check.py lift ≥ ×1.35; beatSync() for ambient tracks, beat grid for rhythmic ones). text-driven films → travelling follow-cam that GLIDES (spline e:"glide" through word targets, bell eases between regions — never per-word hops); element-driven films → near-locked camera with only motivated, seeded moves (camSeed, seed) — never travel for its own sake, never a repeated pattern. Earlier rule, still true for text films: (round 2: "it's just the perspective, the camera isn't moving"): follow-cam on the active word/protagonist across a world bigger than the frame, carrier travel between stations for single-object stories, parallax reference layer always ($KIT/grammar/08-camera.md § v3, $KIT/research/camera-notes.md, primitives §19–20). Also: (the user called its absence a "MAJOR MAJOR MAJOR FLAW"): build every film as a 3D world seen through camera-rig.js; camera moving ≥ 65 % of frames (references: median 77 %, measured with research/camera_motion.py); captions ride the world, dwells keep travelling, dwell-and-sweep rhythm, ≥ 3 depth layers with parallax, DOF, handheld drift, motion blur on sweeps ($KIT/grammar/08-camera.md).
5. Polish bar ($KIT/grammar/09-polish-bar.md): tight glows only (no halos, never scale a glowing element, no large SVG blur filters — gradients + grain); container morphs are SVG geometry so corners stay round every frame (no clip-path reveals); text-bearing UI arrives from depth/soft focus — no scale-pops, no tilted sticker layouts; every flat object gets shade + rim + contact shadow.
6. Professional elements and fonts: build UI/3D pieces from $KIT/elements/ (see elements/showcase/ and research/element-notes.md); type from $KIT/fonts/FONTS.md — never generic defaults.
7. Professional finish: one accent per line, italic-serif or weight-jump emphasis, every frame has ≤ 3 focal elements, a persistent constant (canvas, title, horizon or fog) across the film.
8. Reels first unless told otherwise: 1080×1920, text in the 168–1330 px band, ≤ 5 words per line, nothing under 28 px, frame 0 is the hook (never black, never a logo).
9. Be token-efficient: one scene file per chapter (or one for a whole continuous morph), snapshot only state changes.

Workflow

1. Brief (short). Subject/brand, message, format, length, the music file. Ask only what is missing; one round.
2. Pick a style from $KIT/styles/STYLES.md (table at the bottom maps briefs → styles). Read that card fully; open 1–2 of its reference notes in $KIT/research/video-notes/ for specifics.
3. Analyse the music: npx hyperframes audio <track> --only kind,bpm,beats,downbeats,sections,onsets --json. Rhythmic → beat grid (beat(n), bar(k), primitives §1). Ambient → chapters on section boundaries, hero events on the strongest onsets (--threshold 0.3).
4. Plan in one table: chapters × (time window, carrier into next, object state, caption, camera move). Name the carrier and the camera move for every seam; if you can't, redesign the seam. Lay the chapters out as places in one 3D world.
5. Build with HyperFrames (load /hyperframes first for the contract). Start from the closest sample (v2 = with camera): $KIT/samples/a-ember-lumen (S1), b-morph-nook (S2), c-neon-aura (S3), d-saas-tally (S4) — cp -R it to the new project, then rewrite. Use $KIT/primitives/PRIMITIVES.md blocks. Put palette + fonts in root data-composition-variables.
6. Verify: npx hyperframes check --json 2>/dev/null (stderr is noisy) → fix errors, weigh warnings → npx hyperframes snapshot --at <every state change + mid-sweep> -o .snap/x → read the contact sheet → fix (zoom into corners and glows: snapshot --zoom). Run through 07-engineering-pitfalls.md and the 09-polish-bar.md checklist. After render, measure camera motion: python3 $KIT/research/camera_motion.py <dir-with-mp4> out.json — target moving_frac ≥ 0.65 (references' lower quartile; median 0.77).
7. Render: npx hyperframes render -o <out>.mp4. Open the Studio preview before a delivery render when the user is reviewing.

Quick references

• Carriers (pick 3–5 per film): element-becomes-world · zoom-through · shape morph · guide object · one card many states · iris · colour flood · blur whip · continuous world camera · anchored word · shape rhyme · carry-across · particle dissolve · medium wipe.
• Ease palette: arrival expo.out/power4.out 0.5–0.9 s · exit power3.in (40–50 % of entrance) · camera/morph power2.inOut · premium spring back.out(1.4) · linear only for orbit/rotation/progress.
• Type: per-word blur-in (no translate) · grey→ink read-along · slot-machine word · highlight pill keyword · italic-serif accent · inline icon in sentence.
• Story shapes: problem(dark)→reveal→features→CTA · chaos→order · one protagonist many states · prompt→result · manifesto with anchored word · micro-loop.

Growing the kit

When the user adds new reference videos: make contact sheets (timestamped, 0.33–1 s sampling) + 10 fps strips on transitions, write a note per video in research/video-notes/, add rows to research/INDEX.md, and fold new patterns into the grammar/style files. When a build teaches a new bug or primitive, add it to 07-engineering-pitfalls.md / PRIMITIVES.md.