rossark-motion-skill

rossark-motion-skill is a method for making drawn things feel alive without making them busy, from a production app's onboarding and paywall art where the brief was "it has to feel ALIVE" and "NO TELEPORTING in the animation". Its principles: never teleport, interpolate everything; calm by default with timed motion and strong curves, no bouncy overshoot unless the project explicitly wants a bouncy brand; small amplitudes, halving when unsure; arcs and pivots, with every moving part drawn as its own layer rotating around its pivot; overlap and follow-through, with phase delays growing along a chain; variety without chaos through seeded phases, speeds, and sizes, never Math.random per frame and never everything in sync; one main action per scene plus two or three idle loops; opacity only to appear or disappear; the layout never moves, motion happens inside the drawing; reduced motion means still, with loops frozen at frame 0 and one-shot scenes showing their final frame; nothing runs unseen, with clocks paused off screen, hidden, or in the background; and every move gets enough frames. The engine has one small motion core per platform: templates for React Native (react-native-svg plus Reanimated) and SwiftUI (TimelineView plus Canvas), with loop clocks, one-shot clocks, keyframe tracks, flow-through acting chains, and shaping helpers for waves, loops, bells, windows, and seeded variety. Recipes by subject give starting numbers for characters, tails, plants, cloth, fire, smoke, water, rain, clouds, lights, machines, phones, vehicles, jiggles, floats, icons, charts, and scenes. Characters get a live face (gliding pupils, blinks every 3 to 4 seconds, breathing, head tilts) and full-body acting rules (poses flow without stopping, moving holds, layered channels, follow-through by delay not springs, bent limbs, 2.5D turns, weight shifts, landings that squash and keep volume, hanging feet in the air, shadows that move with height, props entering from off screen already moving). Interface motion follows frequency rules: the more often people see something, the less it should move. Limits as written: project rules override everything below, so read the project's MOTION.md, CLAUDE.md, and saved animation memory first; a published demo, repo, or product needs original characters and art, since brand mascots and illustrations are trademarks and copyrighted. Credit: created by rossark0. Licence: the vetted file states no licence, so it is recorded as non indiquée. Source: https://github.com/rossark0/rossark-motion-skill, file SKILL.md at the root.