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vendor/OpenMontage/.agents/skills/hyperframes-animation/rules/3d-page-scroll.md

Workspace snapshot · 09/04 14:52


name: 3d-page-scroll description: Full webpage rendered as tilted 3D card that scrolls to reveal specific sections. metadata: tags: 3d, page, scroll, webpage, tilt, product-demo, perspective

3D Page Scroll

A webpage (or long content) presented as a tilted 3D card. Spring-eased scroll reveals specific sections while the static 3D perspective adds physical depth.

How It Works

Two independent transforms combine:

  1. 3D tilt — Static rotateY + rotateX with perspective on the card. The angle does not change during the scene.
  2. Scroll — The content inside the card translates vertically (translateY / y in GSAP) within a clipped container, driven by a GSAP tween. Spring-like deceleration via ease: "power3.out" or "power4.out".

Optional layer:

  1. Spotlight overlay — A radial-gradient mask dims everything except a focal region after the scroll lands. Use to draw attention to one section.

For multi-step scrolling (scroll → pause → scroll), use multiple tl.to(".page-content", { y: -<distance>, ... }, <position>) calls at different timeline positions.

HTML

<div
  class="scene"
  id="page-scroll-scene"
  data-composition-id="page-scroll-scene"
  data-start="0"
  data-duration="5"
  data-track-index="0"
>
  <div class="tilt-card">
    <div class="page-content">
      <!-- Full {Brand} webpage recreation, taller than card height so
           scrolling matters. Each section is real DOM, not a screenshot. -->
      <section class="page-hero">{heroContents}</section>
      <section class="page-features">{featuresContents}</section>
      <section class="page-target" id="target-section">{targetContents}</section>
      <section class="page-cta">{ctaContents}</section>
    </div>

    <div class="spotlight"></div>
  </div>
</div>

CSS (hero-frame layout)

.scene {
  position: relative;
  width: 100%;
  height: 100%;
}

.tilt-card {
  position: absolute;
  left: 50%;
  top: 50%;
  /* tilt + perspective set in CSS only if no other transform tween touches
     this element. If GSAP also tweens scale on .tilt-card, set the tilt
     via gsap.set() to avoid matrix overwrites. */
  transform: translate(-50%, -50%) perspective({perspectivePx}) rotateY({tiltYDeg}) rotateX({tiltXDeg});
  transform-style: preserve-3d;
  width: {cardWidth};
  height: {cardHeight};
  border-radius: 24px;
  background: {cardBackgroundColor};
  overflow: hidden; /* clip the scrolling content */
  /* shadow X-offset sign must match tiltY sign (negative tiltY ⇒ positive X) */
  box-shadow: 40px 30px 80px rgba(0, 0, 0, 0.45);
}

.page-content {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  /* height is intrinsic from sections — taller than .tilt-card.height */
}

.page-content section {
  height: {sectionHeight}; /* sections sized so cumulative offset = target distance */
  padding: 64px;
  /* section-specific styling … */
}

.spotlight {
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: 0;
  background: radial-gradient(
    ellipse 60% 35% at 50% 50%,
    transparent 50%,
    {spotlightDimColor} 100%
  );
}

GSAP Timeline

<script src="https://cdn.jsdelivr.net/npm/gsap@3.14.2/dist/gsap.min.js"></script>
<script>
  window.__timelines = window.__timelines || {};
  const tl = gsap.timeline({ paused: true });

  // Phase 1 — Card enters (optional, can skip if card is in from t=0)
  // Phase 2 — Scroll to the target section.
  // SCROLL_DISTANCE is measured at design time from the page layout
  // (top of .page-content origin to vertical center of #target-section,
  // accounting for card height).
  tl.to(
    ".page-content",
    {
      y: -SCROLL_DISTANCE,
      duration: SCROLL_DUR,
      ease: "power3.out",
    },
    SCROLL_AT,
  );

  // Phase 3 — Spotlight fades in on the target after scroll settles
  tl.to(
    ".spotlight",
    {
      opacity: 1,
      duration: SPOTLIGHT_FADE_DUR,
      ease: "power1.inOut",
    },
    SPOTLIGHT_AT,
  );

  window.__timelines["page-scroll-scene"] = tl;
</script>

Multi-phase scroll variant

// Scroll to section A → hold → scroll to section B.
// SCROLL_DISTANCE_A and SCROLL_DISTANCE_B are both measured from the
// .page-content origin (NOT delta from previous step).
tl.to(
  ".page-content",
  { y: -SCROLL_DISTANCE_A, duration: SCROLL_DUR, ease: "power3.out" },
  SCROLL_AT_A,
);
tl.to(
  ".page-content",
  { y: -SCROLL_DISTANCE_B, duration: SCROLL_DUR, ease: "power3.out" },
  SCROLL_AT_B,
);

GSAP composes successive y: tweens additively when targeting the same property — each tween starts from the value left by the previous tween.

How to Choose Values

  • tiltYDeg — static Y rotation in CSS (or via gsap.set()).
    • Range: -12 to -4 (left-leaning) or 4 to 12 (right-leaning); 0 = no perspective rotation.
    • Effects: bigger magnitude = more dramatic 3D; near 0 collapses to a flat panel.
    • Constraints: shadow X-offset sign must match (negative tiltY ⇒ positive box-shadow X).
  • tiltXDeg — static X rotation.
    • Range: 0-6
    • Effects: positive tilts the top edge away from the viewer.
  • perspectivePx — perspective distance.
    • Range: 800-2000 px
    • Effects: smaller = more dramatic foreshortening; larger = nearly orthographic.
  • cardWidth / cardHeight — card frame size.
    • Constraints: card height < total content height, otherwise scroll has nothing to reveal.
  • sectionHeight — height of each scrolled section.
    • Constraints: sum of all section heights ≥ cardHeight + SCROLL_DISTANCE so the target section ends up within frame after scroll.
  • SCROLL_AT — timeline second at which the scroll tween begins.
    • Constraints: must be ≥ end of any prior fade-in tweens on .page-content.
  • SCROLL_DUR — duration of one scroll tween.
    • Range: 0.8-1.8 s
    • Effects: shorter feels like a hard cut; longer feels programmatic.
  • SCROLL_DISTANCE — pixels to translate .page-content upward.
    • Constraints: measured once at design time from the target section's offset; NOT a free tunable.
  • SPOTLIGHT_AT — timeline second at which the spotlight begins fading in.
    • Constraints: should be ≥ SCROLL_AT + SCROLL_DUR (or slightly earlier for overlapping handoff) so the spotlight reveals the freshly-arrived section.
  • SPOTLIGHT_FADE_DUR — spotlight opacity fade-in duration.
    • Range: 0.4-0.8 s
  • Multi-phase variant — SCROLL_AT_A / SCROLL_AT_B: must satisfy SCROLL_AT_A + SCROLL_DUR ≤ SCROLL_AT_B so the two scrolls don't fight for the y property.

Ease family — discrete choice:

  • power3.out — heavy deceleration; reads as a programmatic scroll that "lands". Default.
  • power4.out — even heavier; reads as a momentum-driven scroll.
  • power2.inOut — symmetric; reads as a cinematic camera pan rather than UI scroll.

Pick one and use it across all scrolls in the scene — mixing easings within one scene reads as jerky.

Key Principles

  • Tilt is static, not animated. The card holds its angle the whole scene.
  • Shadow direction matches tilt: a left-leaning card casts shadow to the right (positive X shadow offset). Mismatch breaks the 3D illusion.
  • Page content is real HTML, not a screenshot. Screenshots can't be individually highlighted or scrolled-to with precision.
  • Use real layout for distances: scroll target distance comes from the actual cumulative section heights, not estimated pixel values.
  • Spotlight as overlay, not inside the page-content — overlay sits above scrolling content and stays fixed relative to the card.

Critical Constraints

  • overflow: hidden on .tilt-card — scrolling content must clip at card boundaries, otherwise it leaks past the rounded corners
  • transform-style: preserve-3d on .tilt-card — required for any 3D children (or for combining perspective with rotations cleanly)
  • Timeline must be paused: gsap.timeline({ paused: true }). Never tl.play() — HF seeks frame-by-frame
  • Registry key = data-composition-id: window.__timelines["page-scroll-scene"] must match scene root's data-composition-id
  • Finite scroll distance — compute from actual content geometry; don't use arbitrary values that may overshoot the content end
  • Same easing across multi-phase scroll — mixing power3.out and power1.inOut looks jerky; pick one for the scene

Combinations

Pairs with HF skills

  • /hyperframes-animation — timeline + ease reference; y: tween basics
  • /hyperframes-core — composition wiring, data-* attributes
  • /hyperframes-cli — hyperframes lint to verify the registry key + duration