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.Group lists
• 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 useAnimate with interrupt-safe async/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 + useTransform computes derived values without triggering re-renders.
• useAnimate sequences are imperative and interrupt-safe — calling animate() mid-flight cancels the previous animation automatically.
• Motion values (useMotionValue, useSpring) are SSR-safe and do not cause hydration errors.

Rules

1. Drag interactions must be tested on touch devices, not just mouse. drag prop works on both but feel and threshold differ.
2. Infinite animations must pause when document.visibilityState === "hidden". Background tabs must not consume GPU/CPU.
3. Swipe threshold must be explicit. Never infer intent from velocity alone; combine offset + velocity checks.
4. useAnimate scope ref must be attached to a mounted DOM element. Calling animate() before mount throws silently.
5. Motion values must not be recreated on render. useMotionValue(0) inside a component body is correct; new MotionValue(0) in a render is not.
6. All token values are imported from motion-foundations. No inline numbers.
7. Custom hooks must handle cleanup. Every window.addEventListener needs a matching removeEventListener in the useEffect return.
8. SVG morphing requires equal path command counts. Paths with different command structures snap instead of interpolating.

Decision Guidance

Choosing the right advanced API

When to use useSpring vs a spring transition

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()


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