SKILL.md
Motion Advanced
Complex, interactive, and physics-based animation patterns.
Requires motion-foundations to be set up first.
Use these when motion-patterns is not enough.
When to Activate
- Building drag-to-dismiss sheets, swipe gestures, or reorderable lists
- Animating text word-by-word, character-by-character, or as a live counter
- Drawing SVG paths, morphing icons, or animating circular progress
- Writing a custom animation hook (
useScrollReveal, magnetic button, cursor follower)
- Sequencing multi-step animations imperatively with
useAnimate
- Building spinners, shimmer skeletons, pulse indicators, or loading button states
Outputs
This skill produces:
- Drag interactions: draggable cards, drag-to-dismiss sheets,
Reorder.Grouplists
- Gesture hooks: swipe detection, long press, pinch outline
- Text animation components: word reveal, character typewriter, number counter
- SVG animation: path draw-on, icon morph, stroke progress ring
- Custom hooks:
useScrollReveal,useHoverScale,useNavigationDirection,useInViewOnce
- Imperative sequences via
useAnimatewith interrupt-safeasync/await
- Loader components: spinner, shimmer, pulse dot, progress bar, button loading state
Principles
- Physics-based motion (
useSpring,springs.*) always feels more natural than duration-based for direct manipulation.
useMotionValue+useTransformcomputes derived values without triggering re-renders.
useAnimatesequences are imperative and interrupt-safe — callinganimate()mid-flight cancels the previous animation automatically.
- Motion values (
useMotionValue,useSpring) are SSR-safe and do not cause hydration errors.
Rules
- Drag interactions must be tested on touch devices, not just mouse.
dragprop works on both but feel and threshold differ.
- **Infinite animations must pause when
document.visibilityState === "hidden".** Background tabs must not consume GPU/CPU.
- Swipe threshold must be explicit. Never infer intent from velocity alone; combine
offset+velocitychecks.
- **
useAnimatescope ref must be attached to a mounted DOM element.** Callinganimate()before mount throws silently.
- Motion values must not be recreated on render.
useMotionValue(0)inside a component body is correct;new MotionValue(0)in a render is not.
- **All token values are imported from
motion-foundations.** No inline numbers.
- Custom hooks must handle cleanup. Every
window.addEventListenerneeds a matchingremoveEventListenerin theuseEffectreturn.
- SVG morphing requires equal path command counts. Paths with different command structures snap instead of interpolating.
Decision Guidance
Choosing the right advanced API
Scenario
API
Drag with physics on release
drag + dragTransition: springs.release
Ordered drag-to-reorder list
Reorder.Group + Reorder.Item
Dismiss on drag offset
drag="y" + onDragEnd offset check
Swipe left/right
drag="x" + onDragEnd offset check
Long press
useLongPress hook
Value smoothed over time
useSpring
Value derived from another
useTransform
Multi-step sequence
useAnimate with async/await
One-shot imperative animation
animate() from motion
Text entering word by word
Stagger on inline-block spans
SVG drawing on
pathLength 0 → 1
SVG morph
d attribute tween (equal commands)
Circular progress
strokeDashoffset tween
When to use useSpring vs a spring transition
useSpring
transition: springs.*
Use for
Cursor follower, pointer-tracked values
Discrete state changes
Updates
Continuous, on every frame
Triggered by state change
Interrupt
Smooth — physics picks up from velocity
Restarts from current value
Core Concepts
useMotionValue + useTransform
Reactive computation without re-renders:
const x = useMotionValue(0)
const opacity = useTransform(x, [-200, 0, 200], [0, 1, 0])
// opacity updates every frame as x changes — no setState, no re-render
useAnimate
Returns [scope, animate]. The scope ref must be attached to a DOM element.
animate() calls are interrupt-safe — calling mid-flight cancels the previous run.
const [scope, animate] = useAnimate()
async function play() {
await animate(".step-1", { opacity: 1 }, { duration: 0.3 })
await animate(".step-2", { x: 0 }, { duration: 0.4 })
animate(".step-3", { scale: 1 }, { duration: 0.25 }) // fire and forget
}
return <div ref={scope}>...</div>
Code Examples
Draggable card
"use client"
import { motion } from "motion/react"
import { springs, motionTokens } from "@/lib/motion-tokens"
<motion.div
drag
dragConstraints={{ left: -100, right: 100, top: -100, bottom: 100 }}
dragElastic={0.1}
whileDrag={{
scale: motionTokens.scale.pop,
boxShadow: "0 16px 40px rgba(0,0,0,0.2)",
}}
dragTransition={springs.release}
/>
Drag-to-dismiss sheet
"use client"
import { motion, useMotionValue, useTransform } from "motion/react"
export function BottomSheet({ onClose }: { onClose: () => void }) {
const y = useMotionValue(0)
const opacity = useTransform(y, [0, 200], [1, 0])
return (
<motion.div
drag="y"
dragConstraints={{ top: 0 }}
style={{ y, opacity }}
onDragEnd={(_, info) => {
// Rule 3: combine offset + velocity
if (info.offset.y > 120 || info.velocity.y > 500) onClose()
}}
/>
)
}
Reorderable list
"use client"
import { Reorder } from "motion/react"
export function SortableList() {
const [items, setItems] = useState(initialItems)
return (
<Reorder.Group axis="y" values={items} onReorder={setItems}>
{items.map((item) => (
<Reorder.Item key={item.id} value={item}>
{item.label}
</Reorder.Item>
))}
</Reorder.Group>
)
}
Swipe detection
"use client"
import { motion } from "motion/react"
const OFFSET_THRESHOLD = 50
const VELOCITY_THRESHOLD = 300
<motion.div
drag="x"
dragConstraints={{ left: 0, right: 0 }}
onDragEnd={(_, info) => {
const swipedRight = info.offset.x > OFFSET_THRESHOLD || info.velocity.x > VELOCITY_THRESHOLD
const swipedLeft = info.offset.x < -OFFSET_THRESHOLD || info.velocity.x < -VELOCITY_THRESHOLD
if (swipedRight) onSwipeRight()
if (swipedLeft) onSwipeLeft()
}}
/>
Long press hook
import { useRef } from "react"
export function useLongPress(callback: () => void, ms = 600) {
const timerRef = useRef<ReturnType<typeof setTimeout>>()
return {
onPointerDown: () => { timerRef.current = setTimeout(callback, ms) },
onPointerUp: () => clearTimeout(timerRef.current),
onPointerLeave: () => clearTimeout(timerRef.current),
}
}
Word-by-word reveal
"use client"
import { motion } from "motion/react"
import { springs } from "@/lib/motion-tokens"
export function AnimatedText({ text }: { text: string }) {
return (
<motion.p
variants={{ visible: { transition: { staggerChildren: 0.05 } } }}
initial="hidden"
animate="visible"
>
{text.split(" ").map((word, i) => (
<motion.span
key={i}
className="inline-block mr-1"
variants={{
hidden: { opacity: 0, y: 12 },
visible: { opacity: 1, y: 0, transition: springs.gentle },
}}
>
{word}
</motion.span>
))}
</motion.p>
)
}
Number counter
"use client"
import { useRef, useEffect } from "react"
import { animate } from "motion"
import { motionTokens } from "@/lib/motion-tokens"
export function Counter({ to }: { to: number }) {
const nodeRef = useRef<HTMLSpanElement>(null)
useEffect(() => {
const controls = animate(0, to, {
duration: motionTokens.duration.crawl,
ease: motionTokens.easing.smooth,
onUpdate: (v) => {
if (nodeRef.current) nodeRef.current.textContent = Math.round(v).toString()
},
})
return controls.stop // Rule 7: cleanup
}, [to])
return <span ref={nodeRef} />
}
SVG path draw-on
"use client"
import { motion } from "motion/react"
import { motionTokens } from "@/lib/motion-tokens"
<motion.path
d="M 0 100 Q 50 0 100 100"
initial={{ pathLength: 0, opacity: 0 }}
animate={{ pathLength: 1, opacity: 1 }}
transition={{ duration: motionTokens.duration.slow, ease: motionTokens.easing.smooth }}
/>
Stroke progress ring
"use client"
import { motion } from "motion/react"
import { motionTokens } from "@/lib/motion-tokens"
const CIRCUMFERENCE = 2 * Math.PI * 40 // r=40
export function ProgressRing({ progress }: { progress: number }) {
return (
<svg width="100" height="100" viewBox="0 0 100 100">
<circle cx="50" cy="50" r="40" fill="none" stroke="#e5e7eb" strokeWidth="8" />
<motion.circle
cx="50" cy="50" r="40"
fill="none" stroke="#6366f1" strokeWidth="8"
strokeLinecap="round"
strokeDasharray={CIRCUMFERENCE}
animate={{ strokeDashoffset: CIRCUMFERENCE - (progress / 100) * CIRCUMFERENCE }}
transition={{ duration: motionTokens.duration.normal, ease: motionTokens.easing.smooth }}
style={{ rotate: -90, transformOrigin: "center" }}
/>
</svg>
)
}
useScrollReveal hook
"use client"
import { useRef } from "react"
import { useScroll, useTransform } from "motion/react"
import { motionTokens } from "@/lib/motion-tokens"
export function useScrollReveal() {
const ref = useRef(null)
const { scrollYProgress } = useScroll({ target: ref, offset: ["start end", "end start"] })
const opacity = useTransform(scrollYProgress, [0, 0.3], [0, 1])
const y = useTransform(scrollYProgress, [0, 0.3], [motionTokens.distance.lg, 0])
return { ref, style: { opacity, y } }
}
// Usage
const { ref, style } = useScrollReveal()
<motion.section ref={ref} style={style} />
Cursor follower
"use client"
import { useEffect } from "react"
import { motion, useMotionValue, useSpring } from "motion/react"
import { springs } from "@/lib/motion-tokens"
export function CursorFollower() {
const x = useMotionValue(-100)
const y = useMotionValue(-100)
const sx = useSpring(x, springs.gentle)
const sy = useSpring(y, springs.gentle)
useEffect(() => {
const move = (e: MouseEvent) => { x.set(e.clientX); y.set(e.clientY) }
window.addEventListener("mousemove", move)
return () => window.removeEventListener("mousemove", move) // Rule 7
}, [])
return (
<motion.div
className="fixed top-0 left-0 w-6 h-6 rounded-full bg-indigo-500
pointer-events-none -translate-x-1/2 -translate-y-1/2 z-50"
style={{ x: sx, y: sy }}
/>
)
}
Shimmer skeleton
"use client"
import { useEffect } from "react"
import { motion, useAnimation } from "motion/react"
import { motionTokens } from "@/lib/motion-tokens"
export function ShimmerSkeleton({ className = "" }: { className?: string }) {
const controls = useAnimation()
useEffect(() => {
const play = () =>
controls.start({
x: ["-100%", "100%"],
transition: {
repeat: Infinity,
duration: motionTokens.duration.crawl,
ease: motionTokens.easing.linear,
},
})
const handleVisibility = () => {
if (document.visibilityState === "hidden") controls.stop()
else void play()
}
void play()
document.addEventListener("visibilitychange", handleVisibility)
return () => {
controls.stop()
document.removeEventListener("visibilitychange", handleVisibility)
}
}, [controls])
return (
<div className={`relative overflow-hidden bg-gray-200 rounded ${className}`}>
<motion.div
className="absolute inset-0 bg-gradient-to-r from-transparent via-white/60 to-transparent"
initial={{ x: "-100%" }}
animate={controls}
/>
</div>
)
}
Button loading state
"use client"
import { motion, AnimatePresence } from "motion/react"
import { motionTokens, springs } from "@/lib/motion-tokens"
export function LoadingButton({
loading,
label,
onClick,
}: {
loading: boolean
label: string
onClick: () => void
}) {
return (
<motion.button
onClick={onClick}
animate={{ opacity: loading ? 0.7 : 1 }}
whileTap={loading ? {} : { scale: motionTokens.scale.press }}
transition={springs.snappy}
disabled={loading}
>
<AnimatePresence mode="wait">
{loading ? (
<motion.span
key="loading"
initial={{ opacity: 0 }} animate={{ opacity: 1 }} exit={{ opacity: 0 }}
transition={{ duration: motionTokens.duration.fast }}
>
…
</motion.span>
) : (
<motion.span
key="label"
initial={{ opacity: 0 }} animate={{ opacity: 1 }} exit={{ opacity: 0 }}
transition={{ duration: motionTokens.duration.fast }}
>
{label}
</motion.span>
)}
</AnimatePresence>
</motion.button>
)
}
Infinite animation with visibility pause
"use client"
import { useEffect } from "react"
import { motion, useAnimation } from "motion/react"
import { motionTokens } from "@/lib/motion-tokens"
export function PulseDot() {
const controls = useAnimation()
useEffect(() => {
const pulse = () =>
controls.start({
scale: [1, 1.4, 1],
opacity: [1, 0.6, 1],
transition: { repeat: Infinity, duration: motionTokens.duration.crawl },
})
// Rule 2: pause when tab is hidden
const handleVisibility = () => {
if (document.visibilityState === "hidden") controls.stop()
else void pulse()
}
void pulse()
document.addEventListener("visibilitychange", handleVisibility)
// Rule 7: stop controls and remove listeners on unmount.
return () => {
controls.stop()
document.removeEventListener("visibilitychange", handleVisibility)
}
}, [controls])
return <motion.span className="w-2 h-2 rounded-full bg-green-400" animate={controls} />
}
End-to-End Example
Drag-to-dismiss sheet with shimmer content, loading state, and reduced motion
support — combining useMotionValue, useTransform, useSafeMotion,
AnimatePresence, and tokens from motion-foundations:
"use client"
import { useState } from "react"
import { motion, AnimatePresence, useMotionValue, useTransform } from "motion/react"
import { springs, motionTokens } from "@/lib/motion-tokens"
import { useSafeMotion } from "@/hooks/use-reduced-motion"
import { ShimmerSkeleton } from "./shimmer-skeleton"
export function DismissibleSheet({
isOpen,
onClose,
loading,
children,
}: {
isOpen: boolean
onClose: () => void
loading: boolean
children: React.ReactNode
}) {
const safe = useSafeMotion(motionTokens.distance.xl)
const y = useMotionValue(0)
const opacity = useTransform(y, [0, 200], [1, 0])
return (
<AnimatePresence>
{isOpen && (
<>
{/* Backdrop */}
<motion.div
key="backdrop"
className="fixed inset-0 bg-black/40"
initial={{ opacity: 0 }}
animate={{ opacity: 1 }}
exit={{ opacity: 0 }}
onClick={onClose}
/>
{/* Sheet — drag-to-dismiss */}
<motion.div
key="sheet"
className="fixed bottom-0 inset-x-0 rounded-t-2xl bg-white p-6"
drag="y"
dragConstraints={{ top: 0 }}
style={{ y, opacity }}
onDragEnd={(_, info) => {
if (info.offset.y > 120 || info.velocity.y > 500) onClose()
}}
initial={safe.initial}
animate={safe.animate}
exit={safe.exit}
transition={springs.gentle}
>
{loading ? (
<div className="space-y-3">
<ShimmerSkeleton className="h-4 w-3/4" />
<ShimmerSkeleton className="h-4 w-1/2" />
<ShimmerSkeleton className="h-20 w-full" />
</div>
) : children}
</motion.div>
</>
)}
</AnimatePresence>
)
}
Constraints / Non-Goals
This skill does not cover:
- Token and spring definitions → see
motion-foundations
- Standard UI patterns (button, modal, stagger, page transitions) → see
motion-patterns
- CSS-only animations or Tailwind
animate-*withoutmotion/react
- Canvas or WebGL-based animation (Three.js, Pixi, etc.)
- Full drag-and-drop systems with external state managers (dnd-kit, react-beautiful-dnd)
- Game-loop or frame-by-frame animation
Anti-Patterns
Anti-pattern
Rule violated
Fix
drag tested only on desktop
Rule 1
Test on touch emulator and real device
animate={{ repeat: Infinity }} with no pause
Rule 2
Add visibilitychange listener
onDragEnd checking only offset, not velocity
Rule 3
Check both info.offset and info.velocity
animate(scope, ...) before useEffect
Rule 4
Call animate() only after mount
const x = new MotionValue(0) in render
Rule 5
Use const x = useMotionValue(0)
transition={{ duration: 1.2 }} inline
Rule 6
Use motionTokens.duration.crawl
useEffect without cleanup
Rule 7
Return removeEventListener / controls.stop
SVG morph between paths with different commands
Rule 8
Normalize path commands before animating
Related Skills
- **
motion-foundations** — defines all tokens, springs,useSafeMotion, and SSR guards imported here. Must be set up before using this skill.
- **
motion-patterns** — handles standard UI patterns (button, modal, stagger, page transitions, scroll reveals). Use it before reaching for the advanced patterns here.