gsap-interact

GSAP Interact — Mouse-Driven Animations

Flow: gsap-setup → gsap-animate → gsap-interact → gsap-optimise → gsap-test

Companion: For GSAP core tween API, invoke gsap-core. For performance methods, invoke gsap-performance. This skill covers interaction recipes only. Requires: greensock/gsap-skills

All patterns assume gsap.context() cleanup is in place (see gsap-animate skill).

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1. 3D Tilt Cards

Cursor-to-rotation calculation

const rect = card.getBoundingClientRect()
const xPct = ((e.clientX - rect.left) / rect.width - 0.5) * 2
const yPct = ((e.clientY - rect.top) / rect.height - 0.5) * 2

Full setup with ctx.add

const TILT_IN  = { duration: 0.35, ease: 'power2.out', overwrite: 'auto' }
const TILT_OUT = { duration: 0.7,  ease: 'elastic.out(1, 0.4)', overwrite: 'auto' }

ctx = gsap.context((self) => {
  gsap.set(card, { transformPerspective: 900, force3D: true })

  self.add('applyTilt', (xPct, yPct) => {
    card.style.willChange = 'transform'
    gsap.to(card, { rotationY: xPct * 14, rotationX: -yPct * 14, ...TILT_IN })
    gsap.to(inner, { x: xPct * 10, y: yPct * 10, force3D: true, ...TILT_IN })
  })

  self.add('resetTilt', () => {
    gsap.to(card, { rotationX: 0, rotationY: 0, ...TILT_OUT,
      onComplete: () => { card.style.willChange = 'auto' } })
    gsap.to(inner, { x: 0, y: 0, force3D: true, ...TILT_OUT })
  })
}, scopeRef.value)

Required CSS: .tilt-wrapper { perspective: 1000px; } .tilt-shell { transform-style: preserve-3d; }

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2. Patterns & Best Practices

// 1. ALL event-handler tweens inside ctx.add for cleanup
self.add('onHover', (el) => { gsap.to(el, { scale: 1.05, overwrite: 'auto' }) })

// 2. overwrite: 'auto' on EVERY rapid-fire tween
gsap.to(el, { x: 100, overwrite: 'auto' })

// 3. will-change: set on start, release onComplete
el.style.willChange = 'transform'
gsap.to(el, { x: 0, onComplete: () => { el.style.willChange = 'auto' } })

// 4. force3D: true on repeatedly animated elements
gsap.set(el, { force3D: true })

See gsap-performance skill for tool selection guidance.

Cleanup checklist

1. Every interactive tween registered via ctx.add('name', fn)
2. ctx.revert() called in onUnmounted
3. transformPerspective set via gsap.set (not per-frame)
4. quickTo instances created in onMounted, not in handlers
5. will-change released in onComplete, never permanent

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References

• references/interaction-patterns.md — Draggable with liveSnap for SVG point editing, macOS Dock magnification effect