Scroll Reveal Section

Installation#

CLI

npx shadcn@latest add https://hantui-theta.vercel.app/r/scroll-reveal.json

Manual

1. Install the dependencies

   npmpnpmbunyarn

   npm install clsx motion tailwind-merge

2. Add the shared helpers

   Components use cn() from lib/utils.ts and the motion tokens below. See Installation if you have not set them up yet.

   lib/motion.ts

   import type { Transition, Variants } from "motion/react";
   
   /** Durations in seconds. */
   export const duration = {
     instant: 0.1,
     quick: 0.18,
     base: 0.28,
     slow: 0.45,
   } as const;
   
   /** Cubic-bezier curves. */
   export const ease = {
     /** Entering, UI response. */
     out: [0.22, 1, 0.36, 1],
     /** Moving on screen. */
     inOut: [0.65, 0, 0.35, 1],
     /** Sheets and the mobile menu. */
     drawer: [0.32, 0.72, 0, 1],
   } as const;
   
   /** Everyday UI: presses, icon swaps, popovers and modals. Exits run at `exitFactor` of the enter. */
   export const ui = {
     press: { scale: 0.96, duration: 0.12 },
     icon: { type: "spring", duration: 0.3, bounce: 0 },
     popover: { duration: 0.18, ease: ease.out },
     modal: { duration: 0.24, ease: ease.out },
     exitFactor: 0.6,
   } as const;
   
   /** Once-per-visit motion on the landing page: hero letters, the reel and the afterimage. */
   export const kinetic = {
     heroLetter: { duration: 0.6, ease: ease.out },
     /** Delay per letter, eased so the wave slows toward the end. */
     heroStep: 0.035,
     reelSwap: { type: "spring", duration: 0.5, bounce: 0.1 },
     /** Two afterimages: lag in seconds and opacity of each. */
     ghost: { lag: [0.04, 0.09], opacity: [0.14, 0.06] },
   } as const;
   
   /** Spring presets. */
   export const spring = {
     snappy: { type: "spring", stiffness: 500, damping: 30 },
     smooth: { type: "spring", stiffness: 260, damping: 26 },
     bouncy: { type: "spring", stiffness: 300, damping: 15 },
   } as const satisfies Record<string, Transition>;
   
   /** Stagger between siblings, in seconds (0.03–0.06). */
   export const stagger = {
     tight: 0.03,
     base: 0.045,
     loose: 0.06,
   } as const;
   
   /** Blur + fade + y-offset. Falls back to a plain fade under reduced motion. */
   export function enterVariants(reduceMotion?: boolean | null, y = 8): Variants {
     if (reduceMotion) {
       return {
         hidden: { opacity: 0 },
         visible: { opacity: 1, transition: { duration: duration.base } },
         exit: { opacity: 0, transition: { duration: duration.quick } },
       };
     }
     return {
       hidden: { opacity: 0, y, filter: "blur(4px)" },
       visible: {
         opacity: 1,
         y: 0,
         filter: "blur(0px)",
         transition: { duration: duration.base, ease: ease.out },
       },
       exit: {
         opacity: 0,
         y: -y / 2,
         filter: "blur(4px)",
         transition: { duration: duration.quick, ease: ease.out },
       },
     };
   }
   
   /** Scale 0.96 → 1 for popovers, menus and dialogs. */
   export function overlayVariants(reduceMotion?: boolean | null): Variants {
     if (reduceMotion) {
       return {
         hidden: { opacity: 0 },
         visible: { opacity: 1, transition: { duration: duration.quick } },
         exit: { opacity: 0, transition: { duration: duration.instant } },
       };
     }
     return {
       hidden: { opacity: 0, scale: 0.96, filter: "blur(2px)" },
       visible: {
         opacity: 1,
         scale: 1,
         filter: "blur(0px)",
         transition: { duration: duration.quick, ease: ease.out },
       },
       exit: {
         opacity: 0,
         scale: 0.96,
         filter: "blur(2px)",
         transition: { duration: duration.instant + 0.02, ease: ease.out },
       },
     };
   }
   
   /** Parent variants that stagger their children in. */
   export function staggerVariants(gap: number = stagger.base, delayChildren = 0): Variants {
     return {
       hidden: {},
       visible: { transition: { staggerChildren: gap, delayChildren } },
       exit: { transition: { staggerChildren: gap / 2, staggerDirection: -1 } },
     };
   }

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3. Copy the source

   components/ui/scroll-reveal/scroll-reveal.tsx

   "use client";
   
   import { Children, useRef, type ComponentProps, type ReactNode, type RefObject } from "react";
   import { motion, useReducedMotion, useScroll, useSpring, type Variants } from "motion/react";
   import { cn } from "@/lib/utils";
   import { duration, ease } from "@/lib/motion";
   
   export interface ScrollRevealProps
     extends Omit<ComponentProps<"section">, "children" | "onAnimationStart" | "onDrag" | "onDragStart" | "onDragEnd"> {
     /** Blocks to reveal; each direct child blurs in on its own as it enters view. */
     children: ReactNode;
     /** Show a reading-progress bar pinned to the top of the section. @default true */
     progress?: boolean;
     /** Scrollable element that contains the section, if it isn't the page. Give it position: relative so offsets measure correctly. */
     container?: RefObject<HTMLElement | null>;
     /** Reveal each block only the first time. @default true */
     once?: boolean;
     /** Fraction of a block that must be visible to reveal it. @default 0.35 */
     amount?: number;
     /** Starting blur in px. @default 8 */
     blur?: number;
   }
   
   export function ScrollReveal({
     children,
     progress = true,
     container,
     once = true,
     amount = 0.35,
     blur = 8,
     className,
     ...props
   }: ScrollRevealProps) {
     const reduceMotion = useReducedMotion();
     const ref = useRef<HTMLElement>(null);
     // 0 when the section's top reaches the top of the viewport, 1 when its bottom reaches the bottom.
     const { scrollYProgress } = useScroll({ target: ref, container, offset: ["start start", "end end"] });
     const scaleX = useSpring(scrollYProgress, { stiffness: 300, damping: 40, restDelta: 0.001 });
   
     const variants: Variants = {
       hidden: reduceMotion ? { opacity: 0 } : { opacity: 0, y: 24, filter: `blur(${blur}px)` },
       visible: {
         opacity: 1,
         y: 0,
         filter: "blur(0px)",
         transition: { duration: reduceMotion ? duration.base : duration.slow + 0.2, ease: ease.out },
         transitionEnd: { filter: "none" },
       },
     };
   
     return (
       <section ref={ref} className={cn("relative", className)} {...props}>
         {progress ? (
           <motion.div
             aria-hidden="true"
             className="sticky top-0 z-10 h-0.5 origin-left rounded-full bg-primary"
             style={{ scaleX: reduceMotion ? scrollYProgress : scaleX }}
           />
         ) : null}
         {Children.toArray(children).map((child, i) => (
           <motion.div key={i} variants={variants} initial="hidden" whileInView="visible" viewport={{ root: container, once, amount }}>
             {child}
           </motion.div>
         ))}
       </section>
     );
   }

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Usage#

import { ScrollReveal } from "@/components/ui/scroll-reveal/scroll-reveal";

export function Article() {
  return (
    <ScrollReveal className="space-y-8">
      <h2>Designing motion people don't notice</h2>
      <p>…</p>
      <img src="/figure.jpg" alt="…" />
    </ScrollReveal>
  );
}

API reference#

Accessibility#

• Content is real, in-order markup; only its appearance animates. The progress bar is decorative and aria-hidden.
• With reduced motion enabled, blocks fade in without blur or movement, and the bar tracks scroll directly.