ice-motion

Ice Motion: motion craft

This skill decides how things move. It is called by a workflow (ice-film, ice-explainer, ice-remake, ice-edit, ice-lottie) after the brief and direction exist. It writes the motion plan; it never builds or renders.

1. What this skill owns and what it points to

Owns	Points to
Movement jobs, motion verbs, cause and effect	Kinetic type, captions, reading time, typing cadence of display type: ice-type
Durations, easing, staggers, overlap, springs	Music, SFX, voiceover, beat grids, word timing: ice-audio
Hold policy (alive, camera-only, true still, no idle)	Gates, seam verification, frame scans, density measurement: ice-qa
Cut and transition catalog, transition policy	Engine syntax, render, shutter capture, platform safe zones: ice-engines
Seams, carry, vector law, handoffs	Art and drawing styles, character rigs, narration grammars: ice-styles
Camera, composition, hero size, staging light, the richness measures	Palette, type pairing, anti-sameness fingerprints, decision log: ice-direction
2D, 2.5D and 3D motion; physics; morphing; loops	Arabic and right-to-left letterforms and directions: ice-arabic
Cursor and UI demonstration motion inside films	Shipping app and site UI motion, Lottie, logo vector prep: ice-lottie
Move deck, atomic moves, shot blueprints	Asset truth, real UI capture, logos: ice-assets

Point to other skills by name; never restate their rules.

2. Procedure when called

1. Read the brief slots (film or edit type, platform, aspect, duration, language, register, brand words) and the direction log. If the type is missing, ask the workflow, do not guess.
2. Open references/motion-language-by-type.md and set the film's motion language: hold policy, transition policy, camera policy, overshoot policy, clock and blur grammar, pace. Apply the industry and brand personality presets only where the brief is silent.
3. Write the motion personality: one metaphor plus 3-5 rules (references/motion-grammar.md section 8). Several varied examples exist there; never copy one.
4. Deal the motion palette: 3 core moves, at most 2 accents, at most 1 signature, avoiding the previous film's core moves (references/move-deck.md, references/anti-slideshow-and-density.md section 6).
5. For every beat, write its movement job and verb, timing and ease, and its importance level (references/motion-grammar.md, references/timing-and-easing.md, references/measured-motion.md).
6. For every boundary, write a seam row with the carrier, exit and entry vectors and the reason (references/seams-and-carry.md, references/transition-policy.md, references/cut-catalog.md).
7. For every camera move, write its reason and window (references/camera.md).
8. Check the plan against the anti-slideshow rules and the density targets for the type (references/anti-slideshow-and-density.md), and against the visual richness floor: read the floor numbers from the film type's "Richness floor" table (the ice-film workflow's references/film-types/<type>.md) and the measures and fixes in references/composition-and-staging.md section 7. A shot below the floor is re-staged before anything is built.
9. For commercials, product journeys and no-voice-over text-led films, also write the machine-checkable motion contract (shape: assets/motion-contract.example.json; doctrine: references/continuous-journey.md) and run python scripts/validate_motion_contract.py ice/plan/motion-contract.json --project-root . until it prints PASS. Hand the plan to the workflow; ice-qa verifies the render. Three things the validator checks literally:
   • References: three role-specific references with decomposition notes. When the dated research found no reference you could actually watch, write "references": [] (or the ones you have) plus "referencesWaiver": {"reason": "<what was searched, why none is watchable>", "researchNote": "ice/research/<note>.md"}; never point a reference at a note that describes a film you did not see.
   • Lineage: across each boundary it compares ids, not pictures: transition.semanticId of the outgoing scene must equal entry.semanticId of the next scene, so give the carried object the same semanticId on both sides. That the picture really carries is judged on the render by ice-qa and the reviewer.
   • Generic verbs (slide, grow, scale, float and the rest of its list) fail unless the object literally is that mechanism; then add "literalMechanism": "<the real mechanism in one sentence>" to that primaryMotion or text unit.
10. Log every motion decision with its reason and source through ice-direction (ice/DIRECTION.md).

3. Universal laws (hold in every type)

1. Every movement does a job (direct attention, carry continuity, show change, express character) or it is cut.
2. Motion follows meaning: flows flow, builds assemble, countdowns tick, routes draw in their direction, numbers count while their cause changes.
3. One focal motion at a time; supporting elements wait, the focal one never waits.
4. Entrances decelerate, exits accelerate, on-screen moves ease in and out, impacts accelerate into contact; never linear for spatial moves unless mechanical; never one ease on everything (at least 3 easing characters per film).
5. Exits are faster than entrances; entries use 2-3 decaying channels, never opacity alone; never grow from zero.
6. Staggers stay under about 0.5 s per group, irregular, in order of importance; offsets shorter than the moves they offset.
7. Contrast is the message: vary speed (slowest scene about 3x the fastest), shot length, density and stillness; spend scale, effects and accents once.
8. Something crosses every boundary: a carried object, a matched vector, the voice or the beat; scene A's exit decides scene B's entry (same axis, direction, speed).
9. The camera is punctuation: it moves for one named reason, slow for transitions, fast only for accents, never three pushes inward in a row.
10. Holds are decisions: the film's hold policy is chosen by type and applied everywhere; a scene that runs out of content is shortened or given story, never wobble.
11. Every frame is a pure function of time: closed-form springs, seeded randomness, no wall clock, no stateful solvers.
12. Effects never compensate for weak layout, weak poses or missing evidence.

4. Conflicts resolved by scope (summary)

Question	Answer by type	File
What moves during a hold?	Alive (launch, app ad, social, hype), camera only (explainer, talking-head, data, long-form), true still as punctuation (brand, art rests, kinetic rests, comedy), no idle (UI walkthrough, narrated launch)	references/holds-and-stillness.md
Crossfades?	Banned between scenes in launch, app ad, hype, kinetic, collage, music-led, social; allowed as "this continues" in calm brand, art, long-form, podcast, chart-to-chart	references/transition-policy.md
Hard cuts?	About 95 percent of changes in edited footage, explainers and collage; in camera-is-the-editor films only on a downbeat, at most twice	references/transition-policy.md
Overshoot?	None for data, finance, health, luxury, camera, text; tiny for launch and UI; one spring per consumer film; playful only for kids and mascots	references/timing-and-easing.md
Exits on non-final scenes?	Banned where the transition is the exit (assembled launch films); short accelerating exits or demote-in-place in narrated explainers	references/transition-policy.md
Fill the frame or big empty ground?	Fill (business spots, explainers, every vertical ad) or about 70 percent textured ground (minimal genre references, calm brands, landscape only): choose by reference genre and register. Either way the type's richness floor holds; "premium" subtracts clutter, never fullness	references/composition-and-staging.md sections 2 and 7
Camera during holds?	Slow push 3-6 percent (policies A and B); locked (C and D)	references/camera.md, references/holds-and-stillness.md

5. Output contract: the motion plan

The workflow stores it as ice/plan/motion-plan.md. Fill every slot; slots are placeholders, never example values.

## Motion language
type: <film or edit type> | hold policy: <A|B|C|D> | transitions: <primary + accents> | camera policy: <...>
overshoot: <none|tiny|one spring|playful> | clock: <fps, smooth or stepped> | blur grammar: <smear|crisp|shutter>
personality: <one metaphor> + <3-5 rules>
palette: core <move, move, move> | accents <move, move> | signature <move or none>
richness: hero_share <n> | hero_width <n or n/a> | frame_fill <n of 16> | empty_half <s> | depth_layers <n> | in_shot_motion <n percent> | longest_still <s> | light_events <n> | real_material <percent or n/a> (floor numbers from the film-type file)

## Beats (one row each)
| t in-out | beat role | importance 1-3 | focal element | job | verb | ease | duration | stagger | buys |

## Seams (one row per boundary)
| cut t | out motion (axis, direction, speed, blur) | seam type | in motion | carrier | ease pair | cue | reason |

## Camera windows
| from | apex | dwell end | to | target | move | reason |

6. Files

Need	Open	When
Set the motion language for a type, industry or brand	references/motion-language-by-type.md	First, every time
Decide whether and why something moves; verbs; cause and effect; personality	references/motion-grammar.md	Planning every beat
Durations, ease direction, staggers, overlap law, overshoot policy, timing anchors	references/timing-and-easing.md	Timing every beat
Measured human numbers and the 12 fitted eases	references/measured-motion.md and scripts/measured-eases.mjs	Launch, app ad, UI, hype; matching a reference move
Spring formulas, damping guide, preset families, named cubic-bezier curves	references/springs-and-curves.md and scripts/springs.mjs	Any spring or custom curve
What happens during holds; end holds; freezes; loops	references/holds-and-stillness.md	Before any hold or ending
Exact construction of a cut or transition	references/cut-catalog.md	Building a seam
Which transition, how many, crossfade and exit policy, seam plan fields	references/transition-policy.md	Choosing seams
Carry, vector law, handoff contracts, tolerances, root protagonist	references/seams-and-carry.md	Every boundary
One-shape, one-world and one-actor films	references/one-take-films.md	The direction calls for a continuous film
Camera reasons, rig rules, move durations, shake, density limits	references/camera.md	Any camera move
Focal point, hero size, layers, layout, staging, staging light, the visual richness floor (section 7)	references/composition-and-staging.md	Framing every shot; checking the plan in step 8
2D vs 2.5D vs 3D, parallax, depth of field, 3D flight values	references/depth-and-3d.md	Depth or 3D beats
Slideshow failure modes, rhythm, density targets, spending rules	references/anti-slideshow-and-density.md	Reviewing the plan
Animation principles as engineering, physics recipes, morphing, draw-on, loops	references/physics-and-morphing.md	Physical or morphing beats
Cursor, click, drag, toggles, agent states, UI demo recipes	references/cursor-and-ui.md	Any UI demonstration
Small moves with value tables and an intent picker	references/atomic-moves.md	Choosing a move for one beat
46-card move deck, refused names, mechanism catalogs	references/move-deck.md	Dealing the motion palette
Time-coded blueprints, shot constructions, time skeletons	references/shot-blueprints.md	Planning a shot sequence
Frame clocks, blur grammars, when to motion-blur, grain	references/motion-blur-and-clock.md	Setting the clock and blur
One root protagonist, state chain, inheritance channels, hard-cut records, text that acts, closure (founder's original)	references/continuous-journey.md	Commercials and product journeys
Physical decision contract, throw, attraction, rigid UI closure, sound by motion phase (founder's original)	references/motion-choreography.md	Physical or causal beats
Frame and text focus-unit contracts, camera necessity test, camera verbs, 2D anchor formula (founder's original)	references/semantic-camera.md	Every camera decision in commercials
Motion contract shape	assets/motion-contract.example.json	Writing a motion contract (values are illustration only)

Scripts (Windows, macOS, Linux). Minimum Node and Python versions: runtimes in the ice-engines skill's references/versions.json; Python packages: scripts/requirements.txt (exact pins in sync with versions.json).

Script	Runtime	Use
node scripts/measured-eases.mjs [ease] [samples]	Node	Print or import the 12 measured eases
node scripts/springs.mjs [w z seconds]	Node	Print or import closed-form springs and settle times
python scripts/validate_motion_contract.py <contract.json> [--project-root <folder>]	Python, standard library	Strict causal, temporal, disclosure, lineage, camera and sound contract gate; exit 1 lists failures
python scripts/audit_web_section_motion.py <project folder>	Python, standard library	Rejects animated-web-section code patterns (exit 1)
python scripts/audit_motion.py --video <mp4> --audio <wav>	Python with numpy and opencv-python-headless	Audio onsets and visual-change density versus a reference; a diagnostic, not a verdict

The founder's files carry the note "From the founder's commercial-motion-design skill".