<!--
Sections animate in and out on scroll. Scroll up or down and the sections will wrap around after hitting the start or end. Uses GSAP for the animations.
-->

<header>
  <div>Animated Sections</div>
  <div>Made By Brian</div>
</header>
<section class="first">
  <div class="outer">
    <div class="inner">
      <div class="bg one">
        <h2 class="section-heading">Scroll down</h2>
      </div>
    </div>
  </div>

</section>
<section class="second">
  <div class="outer">
    <div class="inner">
      <div class="bg">
        <h2 class="section-heading">Animated with GSAP</h2>
      </div>
    </div>
  </div>
</section>
<section class="third">
  <div class="outer">
    <div class="inner">
      <div class="bg">
        <h2 class="section-heading">GreenSock</h2>
      </div>
    </div>
  </div>
</section>
<section class="fourth">
  <div class="outer">
    <div class="inner">
      <div class="bg">
        <h2 class="section-heading">Animation platform</h2>
      </div>
    </div>
  </div>
</section>
<section class="fifth">
  <div class="outer">
    <div class="inner">
      <div class="bg">
        <h2 class="section-heading">Keep scrolling</h2>
      </div>
    </div>
  </div>
</section>
@import url("https://fonts.googleapis.com/css2?family=Bebas+Neue&display=swap");
@import url("https://fonts.googleapis.com/css2?family=Cormorant+Garamond&display=swap");

$bg-gradient: linear-gradient(
  180deg,
  rgba(0, 0, 0, 0.6) 0%,
  rgba(0, 0, 0, 0.3) 100%
);

* {
  box-sizing: border-box;
  user-select: none;
}

body {
  margin: 0;
  padding: 0;
  height: 100vh;
  color: white;
  background: black;
  font-family: "Cormorant Garamond", serif;
  text-transform: uppercase;
}

h2 {
  font-size: clamp(1rem, 5vw, 5rem);
  font-weight: 400;
  text-align: center;
  letter-spacing: 0.5em;
  margin-right: -0.5em;
  color: hsl(0, 0, 80%);
  width: 90vw;
  max-width: 1200px;
}

header {
  position: fixed;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 5%;
  width: 100%;
  z-index: 3;
  height: 7em;
  font-family: "Bebas Neue", sans-serif;
  font-size: clamp(0.66rem, 2vw, 1rem);
  letter-spacing: 0.5em;
}

section {
  height: 100%;
  width: 100%;
  top: 0;
  position: fixed;
  visibility: hidden;
  will-change: transform;

  .outer,
  .inner {
    width: 100%;
    height: 100%;
    overflow-y: hidden;
    will-change: transform;
  }

  .bg {
    display: flex;
    align-items: center;
    justify-content: center;
    position: absolute;
    height: 100%;
    width: 100%;
    top: 0;
    background-size: cover;
    background-position: center;

    h2 {
      z-index: 2;
    }

    .clip-text {
      overflow: hidden;
    }
  }
}

.first {
  .bg {
    background-image: $bg-gradient,
      url(https://images.unsplash.com/photo-1617478755490-e21232a5eeaf?crop=entropy&cs=srgb&fm=jpg&ixid=MnwxNDU4OXwwfDF8cmFuZG9tfHx8fHx8fHx8MTYxNzU1NjM5NA&ixlib=rb-1.2.1&q=75&w=1920);
  }
}

.second {
  .bg {
    background-image: $bg-gradient,
      url("https://images.unsplash.com/photo-1617128734662-66da6c1d3505?crop=entropy&cs=tinysrgb&fit=max&fm=jpg&ixid=MnwxNDU4OXwwfDF8cmFuZG9tfHx8fHx8fHx8MTYxNzc3NTM3MA&ixlib=rb-1.2.1&q=75&w=1920");
  }
}

.third {
  .bg {
    background-image: $bg-gradient,
      url(https://images.unsplash.com/photo-1617438817509-70e91ad264a5?crop=entropy&cs=srgb&fm=jpg&ixid=MnwxNDU4OXwwfDF8cmFuZG9tfHx8fHx8fHx8MTYxNzU2MDk4Mg&ixlib=rb-1.2.1&q=75&w=1920);
  }
}

.fourth {
  .bg {
    background-image: $bg-gradient,
      url(https://images.unsplash.com/photo-1617412327653-c29093585207?crop=entropy&cs=srgb&fm=jpg&ixid=MnwxNDU4OXwwfDF8cmFuZG9tfHx8fHx8fHx8MTYxNzU2MDgzMQ&ixlib=rb-1.2.1&q=75&w=1920);
  }
}

.fifth {
  .bg {
    background-image: $bg-gradient,
      url("https://images.unsplash.com/photo-1617141636403-f511e2d5dc17?crop=entropy&cs=srgb&fm=jpg&ixid=MnwxNDU4OXwwfDF8cmFuZG9tfHx8fHx8fHx8MTYxODAzMjc4Mw&ixlib=rb-1.2.1&q=75w=1920");
    background-position: 50% 45%;
  }
}
View Compiled
const sections = document.querySelectorAll("section");
const images = document.querySelectorAll(".bg");
const headings = gsap.utils.toArray(".section-heading");
const outerWrappers = gsap.utils.toArray(".outer");
const innerWrappers = gsap.utils.toArray(".inner");

document.addEventListener("wheel", handleWheel);
document.addEventListener("touchstart", handleTouchStart);
document.addEventListener("touchmove", handleTouchMove);
document.addEventListener("touchend", handleTouchEnd);

let listening = false,
  direction = "down",
  current,
  next = 0;

const touch = {
  startX: 0,
  startY: 0,
  dx: 0,
  dy: 0,
  startTime: 0,
  dt: 0
};

const tlDefaults = {
  ease: "slow.inOut",
  duration: 1.25
};

const splitHeadings = headings.map((heading) => {
  return new SplitText(heading, {
    type: "chars, words, lines",
    linesClass: "clip-text"
  });
});

function revealSectionHeading() {
  return gsap.to(splitHeadings[next].chars, {
    autoAlpha: 1,
    yPercent: 0,
    duration: 1,
    ease: "power2",
    stagger: {
      each: 0.02,
      from: "random"
    }
  });
}

gsap.set(outerWrappers, { yPercent: 100 });
gsap.set(innerWrappers, { yPercent: -100 });

// Slides a section in on scroll down
function slideIn() {
  // The first time this function runs, current is undefined
  if (current !== undefined) gsap.set(sections[current], { zIndex: 0 });

  gsap.set(sections[next], { autoAlpha: 1, zIndex: 1 });
  gsap.set(images[next], { yPercent: 0 });
  gsap.set(splitHeadings[next].chars, { autoAlpha: 0, yPercent: 100 });

  const tl = gsap
    .timeline({
      paused: true,
      defaults: tlDefaults,
      onComplete: () => {
        listening = true;
        current = next;
      }
    })
    .to([outerWrappers[next], innerWrappers[next]], { yPercent: 0 }, 0)
    .from(images[next], { yPercent: 15 }, 0)
    .add(revealSectionHeading(), 0);

  if (current !== undefined) {
    tl.add(
      gsap.to(images[current], {
        yPercent: -15,
        ...tlDefaults
      }),
      0
    ).add(
      gsap
        .timeline()
        .set(outerWrappers[current], { yPercent: 100 })
        .set(innerWrappers[current], { yPercent: -100 })
        .set(images[current], { yPercent: 0 })
        .set(sections[current], { autoAlpha: 0 })
    );
  }

  tl.play(0);
}

// Slides a section out on scroll up
function slideOut() {
  gsap.set(sections[current], { zIndex: 1 });
  gsap.set(sections[next], { autoAlpha: 1, zIndex: 0 });
  gsap.set(splitHeadings[next].chars, { autoAlpha: 0, yPercent: 100 });
  gsap.set([outerWrappers[next], innerWrappers[next]], { yPercent: 0 });
  gsap.set(images[next], { yPercent: 0 });

  gsap
    .timeline({
      defaults: tlDefaults,
      onComplete: () => {
        listening = true;
        current = next;
      }
    })
    .to(outerWrappers[current], { yPercent: 100 }, 0)
    .to(innerWrappers[current], { yPercent: -100 }, 0)
    .to(images[current], { yPercent: 15 }, 0)
    .from(images[next], { yPercent: -15 }, 0)
    .add(revealSectionHeading(), ">-1")
    .set(images[current], { yPercent: 0 });
}

function handleDirection() {
  listening = false;

  if (direction === "down") {
    next = current + 1;
    if (next >= sections.length) next = 0;
    slideIn();
  }

  if (direction === "up") {
    next = current - 1;
    if (next < 0) next = sections.length - 1;
    slideOut();
  }
}

function handleWheel(e) {
  if (!listening) return;
  direction = e.wheelDeltaY < 0 ? "down" : "up";
  handleDirection();
}

function handleTouchStart(e) {
  if (!listening) return;
  const t = e.changedTouches[0];
  touch.startX = t.pageX;
  touch.startY = t.pageY;
}

function handleTouchMove(e) {
  if (!listening) return;
  e.preventDefault();
}

function handleTouchEnd(e) {
  if (!listening) return;
  const t = e.changedTouches[0];
  touch.dx = t.pageX - touch.startX;
  touch.dy = t.pageY - touch.startY;
  if (touch.dy > 10) direction = "up";
  if (touch.dy < -10) direction = "down";
  handleDirection();
}

slideIn();
Run Pen

External CSS

  1. https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.15.2/css/all.min.css

External JavaScript

  1. https://cdnjs.cloudflare.com/ajax/libs/gsap/3.6.0/gsap.min.js
  2. https://cdnjs.cloudflare.com/ajax/libs/gsap/3.6.0/CSSRulePlugin.min.js
  3. https://s3-us-west-2.amazonaws.com/s.cdpn.io/16327/CustomBounce3.min.js
  4. https://s3-us-west-2.amazonaws.com/s.cdpn.io/16327/CustomEase3.min.js
  5. https://s3-us-west-2.amazonaws.com/s.cdpn.io/16327/CustomWiggle3.min.js
  6. https://s3-us-west-2.amazonaws.com/s.cdpn.io/16327/DrawSVGPlugin3.min.js
  7. https://cdnjs.cloudflare.com/ajax/libs/gsap/3.6.0/Draggable.min.js
  8. https://cdnjs.cloudflare.com/ajax/libs/gsap/3.6.0/EaselPlugin.min.js
  9. https://cdnjs.cloudflare.com/ajax/libs/gsap/3.6.0/EasePack.min.js
  10. https://s3-us-west-2.amazonaws.com/s.cdpn.io/16327/Flip.min.js
  11. https://s3-us-west-2.amazonaws.com/s.cdpn.io/16327/GSDevTools3.min.js
  12. https://s3-us-west-2.amazonaws.com/s.cdpn.io/16327/InertiaPlugin.min.js
  13. https://s3-us-west-2.amazonaws.com/s.cdpn.io/16327/MorphSVGPlugin3.min.js
  14. https://s3-us-west-2.amazonaws.com/s.cdpn.io/16327/MotionPathHelper.min.js
  15. https://cdnjs.cloudflare.com/ajax/libs/gsap/3.6.0/MotionPathPlugin.min.js
  16. https://s3-us-west-2.amazonaws.com/s.cdpn.io/16327/Physics2DPlugin3.min.js
  17. https://s3-us-west-2.amazonaws.com/s.cdpn.io/16327/PhysicsPropsPlugin3.min.js
  18. https://cdnjs.cloudflare.com/ajax/libs/gsap/3.6.0/PixiPlugin.min.js
  19. https://s3-us-west-2.amazonaws.com/s.cdpn.io/16327/ScrambleTextPlugin3.min.js
  20. https://cdnjs.cloudflare.com/ajax/libs/gsap/3.6.0/ScrollToPlugin.min.js
  21. https://cdnjs.cloudflare.com/ajax/libs/gsap/3.6.0/ScrollTrigger.min.js
  22. https://s3-us-west-2.amazonaws.com/s.cdpn.io/16327/SplitText3.min.js
  23. https://cdnjs.cloudflare.com/ajax/libs/gsap/3.6.0/TextPlugin.min.js