/motion-craft

name: motion-craft
description: "Use when deciding how a film beat looks and moves — motion density (a gesture in progress at every moment: 0.75 s gesture-free max, CTA still ≤ 1.2 s, beats every 0.5-1 s, ≥ 1 onset/s) with read time ≥ 0.25 s/word, one primary gesture with subordinate details, the two film types (cut-based edit, one continuous object), scene transitions without opacity blends, easing and springs (ζ ≥ 0.85, ≤ 3 % overshoot, springSum, dual-edge), ink/paper/one-accent color with area-weighted contrast and type as a large object, and the single-source ban list (every decorative effect banned); also the rubric source motion-critic scores against."
versions:
  fuse-motion: "1.0.0"
user-invocable: false
references: references/focus-hierarchy.md, references/timing-holds.md, references/continuous-take.md, references/easing-springs.md, references/color-type-video.md, references/anti-slop-video.md
related-skills: motion-method, motion-art-direction, motion-review, motion-render, fuse-design:design-motion

<objective> The craft rules for film motion — what moves, for how long, on which curve, in which color, at what type size — and the bans that separate a directed film from generic "AI motion". `motion-expert` applies them while building each beat; `motion-critic` scores against the same rules through `motion-review`, so a rule stated here is a rule the draft is judged on.

It does not own UI motion tokens: easing curves and the glossary live in `fuse-design:design-motion` and are pointed to, never copied. UI micro-durations from that skill (100-500 ms) do not apply to film read time. And readable never means frozen: a purposeful gesture is in progress at every moment — no span over 0.75 s without one, the final CTA still ≤ 1.2 s — and nothing "drifts" to fake life; a long read becomes more beats. </objective>

Motion Craft

Agent Workflow (MANDATORY)

| Step | Who | What | |------|-----|------| | Before choosing curves | read `fuse-design:design-motion` → [motion-tokens.md](../../../design-expert/skills/design-motion/references/motion-tokens.md) | Reuse the named easing tokens | | Naming an effect | [animation-glossary.md](../../../design-expert/skills/design-motion/references/animation-glossary.md) | Exact term in beats and handoff | | Building a scene | `motion-art-direction` templates first: [composition-grid](../motion-art-direction/references/templates/composition-grid.md), [kinetic-type](../motion-art-direction/references/templates/kinetic-type.md), [cut-rhythm](../motion-art-direction/references/templates/cut-rhythm.md) | Grid, entrances and cut times that already enforce these rules | | Draft review | `motion-critic` via `motion-review` | Scores these rules with frame refs | | Scripts | `fuse-ai-pilot:sniper` | Code validation after scene/render edits |

---

Overview

| Area | Core rule | Reference | |------|-----------|-----------| | **Focus** | One primary gesture at a time, smaller details (rules, underlines, counters) may move with it; frame 0 at full value; behaviours rotate, never opacity-only | [focus-hierarchy.md](references/focus-hierarchy.md) | | **Timing & density** | Gesture in progress at every moment: ≤ 0.75 s gesture-free, CTA still ≤ 1.2 s, beats every 0.5-1 s, ≥ 1 onset/s; ≥ 0.25 s per word on screen; long copy → more beats; no drift | [timing-holds.md](references/timing-holds.md) | | **Continuous take** | Cut-based edit or one continuous object (morph, cursor, content swap); no opacity blend; one curve; loops with matched velocity | [continuous-take.md](references/continuous-take.md) | | **Easing** | No linear motion; springs ζ ≥ 0.85, overshoot ≤ 3 %, one swing at most; springSum; dual-edge squash/stretch | [easing-springs.md](references/easing-springs.md) | | **Color & type** | Ink / paper / one accent (OKLCH); area-weighted contrast ≥60 L; a ≥50 % dark/accent plane on 1 beat in 3; no neutral mid-tones; TYPE_SCALE ≥4; never centered | [color-type-video.md](references/color-type-video.md) | | **Anti-slop** | Single-source ban list, each absolute ban mapped to a hard-fail ID; no `look.md` exception | [anti-slop-video.md](references/anti-slop-video.md) |

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Critical Rules

1. **One primary gesture at a time** — smaller, subordinate details (a rule, an underline, a counter, a motion path) may move with it; two big moves at once = no focus. 2. **Frame 0 is the statement** — the opening line is on screen at full value at t = 0; no blank, logo or fading-in first frame. 3. **Continuous purposeful motion, readable, never drifting** — a gesture in progress at every moment: no span > 0.75 s without one, the final CTA still ≤ 1.2 s, beats every 0.5-1 s on the grid, ≥ 1 onset/s; every word ≥ 0.25 s on screen, long copy split into more beats. No slow push, no ambient loop. 4. **No opacity blends** — no crossfade, no dissolve, no opacity-only reveal. Transitions are a shape morph, a hard-edged mask wipe, push/swap, or a hard cut on the grid; one fixed curve for every morph and the camera (field example: 0.8 s `cubic-bezier(.45,0,.15,1)`). 5. **Kinetic type and objects, rotated** — letter/word stagger, slam, scale jump 3-4× → set size, split along a plane; one recurring geometric actor; objects that assemble and transform; never the same behaviour on two consecutive beats. 6. **No linear motion** — except constant-rate indicators (progress fill, cursor travel at typing speed). 7. **Springs: ζ ≥ 0.85, overshoot ≤ 3 %, one swing at most** — presets 320/31 (UI, ζ 0.87), 170/23 (containers, 0.88), 120/19 (heavy type, 0.87); snappy expo-out arrivals. 8. **Ink / paper / one accent, no neutral mid-tones** — no fill at OKLCH L 30-85 with C < 0.03; the two largest planes differ by ≥60 L; at least one beat in three is ≥50 % dark or accent field; body text ≥7:1. 9. **Type as a large object, never centered** — TYPE_SCALE ≥4 on hero frames, flush-left or edge-anchored, at least one crop/bleed; px at the 1080-wide output; judge legibility at 360-390 px. 10. **