Three.js Product Spotlight

:root {
  --bg: #04070f;
  --text: #eff4ff;
  --muted: #c2d0e7;
  --accent: #8de8ff;
}
* {
  box-sizing: border-box;
}
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Avenir Next", "Segoe UI", sans-serif;
}
#scene {
  position: fixed;
  inset: 0;
  z-index: 0;
}
.topbar {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 30;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: .75rem 1rem;
  background: rgba(0, 0, 0, 0.28);
  backdrop-filter: blur(8px);
}
.topbar a {
  color: var(--accent);
  text-decoration: none;
  font-weight: 700;
}
button {
  border: 1px solid rgba(255, 255, 255, 0.25);
  border-radius: 999px;
  padding: .45rem .8rem;
  background: rgba(255, 255, 255, 0.07);
  color: var(--text);
  cursor: pointer;
}
main {
  position: relative;
  z-index: 10;
}
.panel {
  min-height: 90vh;
  width: min(920px, 92%);
  margin: 0 auto;
  display: grid;
  align-content: center;
  gap: .7rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
}
.label {
  margin: 0;
  color: var(--accent);
  letter-spacing: .1em;
  text-transform: uppercase;
}
h1,
h2,
p {
  margin: 0;
}
h1 {
  font-size: clamp(2.1rem, 7vw, 4.3rem);
}
p {
  color: var(--muted);
  max-width: 62ch;
}

if (!window.MotionPreference) {
  const __mql = window.matchMedia("(prefers-reduced-motion: reduce)");
  const __listeners = new Set();

  const MotionPreference = {
    prefersReducedMotion() {
      return __mql.matches;
    },
    setOverride(value) {
      const reduced = Boolean(value);
      document.documentElement.classList.toggle("reduced-motion", reduced);
      window.dispatchEvent(new CustomEvent("motion-preference", { detail: { reduced } }));
      for (const listener of __listeners) {
        try {
          listener({ reduced, override: reduced, systemReduced: __mql.matches });
        } catch {}
      }
    },
    onChange(listener) {
      __listeners.add(listener);
      try {
        listener({
          reduced: __mql.matches,
          override: null,
          systemReduced: __mql.matches,
        });
      } catch {}
      return () => __listeners.delete(listener);
    },
    getState() {
      return { reduced: __mql.matches, override: null, systemReduced: __mql.matches };
    },
  };

  window.MotionPreference = MotionPreference;
}

import * as THREE from "three";

const host = document.getElementById("scene");
const toggle = document.getElementById("toggleMotion");
let motionEnabled = !window.MotionPreference.prefersReducedMotion();

const scene = new THREE.Scene();
scene.background = new THREE.Color(0x03050c);
scene.fog = new THREE.Fog(0x03050c, 10, 40);

const camera = new THREE.PerspectiveCamera(55, window.innerWidth / window.innerHeight, 0.1, 100);
camera.position.set(0, 0.7, 7);

const renderer = new THREE.WebGLRenderer({ antialias: true });
renderer.setPixelRatio(Math.min(window.devicePixelRatio || 1, 2));
renderer.setSize(window.innerWidth, window.innerHeight);
host.appendChild(renderer.domElement);

const product = new THREE.Group();
scene.add(product);

const body = new THREE.Mesh(
  new THREE.CylinderGeometry(1.2, 1.2, 2.4, 48),
  new THREE.MeshStandardMaterial({ color: 0x1e2c47, metalness: 0.6, roughness: 0.25 })
);
product.add(body);

const ring = new THREE.Mesh(
  new THREE.TorusGeometry(1.22, 0.08, 24, 80),
  new THREE.MeshStandardMaterial({
    color: 0x90e8ff,
    emissive: 0x478eb0,
    emissiveIntensity: 0.7,
    metalness: 0.4,
    roughness: 0.2,
  })
);
ring.rotation.x = Math.PI / 2;
ring.position.y = 0.7;
product.add(ring);

const cap = new THREE.Mesh(
  new THREE.CylinderGeometry(1.15, 1.15, 0.35, 48),
  new THREE.MeshStandardMaterial({ color: 0xbccae0, metalness: 0.85, roughness: 0.18 })
);
cap.position.y = 1.35;
product.add(cap);

scene.add(new THREE.AmbientLight(0x98b7ff, 0.45));
const key = new THREE.SpotLight(0x9edbff, 2.2, 60, 0.45, 0.35);
key.position.set(7, 8, 6);
scene.add(key);
const rim = new THREE.PointLight(0xd07cff, 0.8, 30);
rim.position.set(-6, 2, -5);
scene.add(rim);

function getScrollProgress() {
  const max = Math.max(document.body.scrollHeight - window.innerHeight, 1);
  return Math.min(1, Math.max(0, window.scrollY / max));
}

function setLabel() {
  toggle.textContent = motionEnabled ? "Disable motion" : "Enable motion";
}

function animate(time) {
  requestAnimationFrame(animate);
  const t = time * 0.001;
  const p = motionEnabled ? getScrollProgress() : 0;

  const angle = -0.7 + p * 1.35;
  const radius = 7 - p * 2.1;
  camera.position.x += (Math.cos(angle) * radius - camera.position.x) * 0.08;
  camera.position.z += (Math.sin(angle) * radius - camera.position.z) * 0.08;
  camera.position.y += (0.5 + p * 1.4 - camera.position.y) * 0.08;
  camera.lookAt(0, 0.35, 0);

  if (motionEnabled) {
    product.rotation.y += 0.004;
    ring.rotation.z = Math.sin(t * 1.2) * 0.2;
  }

  renderer.render(scene, camera);
}

function onResize() {
  camera.aspect = window.innerWidth / window.innerHeight;
  camera.updateProjectionMatrix();
  renderer.setSize(window.innerWidth, window.innerHeight);
}

toggle.addEventListener("click", () => {
  motionEnabled = !motionEnabled;
  setLabel();
});

window.addEventListener("resize", onResize);
setLabel();
animate(0);

<!doctype html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Demo 12 - Product Spotlight</title>
    <link rel="stylesheet" href="style.css" />
    <script type="importmap">{"imports":{"gsap":"https://esm.sh/[email protected]","gsap/ScrollTrigger":"https://esm.sh/[email protected]/ScrollTrigger","gsap/SplitText":"https://esm.sh/[email protected]/SplitText","gsap/Flip":"https://esm.sh/[email protected]/Flip","gsap/ScrambleTextPlugin":"https://esm.sh/[email protected]/ScrambleTextPlugin","gsap/TextPlugin":"https://esm.sh/[email protected]/TextPlugin","gsap/all":"https://esm.sh/[email protected]/all","gsap/":"https://esm.sh/[email protected]/","lenis":"https://esm.sh/[email protected]/dist/lenis.mjs","three":"https://esm.sh/[email protected]","three/addons/":"https://esm.sh/[email protected]/examples/jsm/"}}</script>
</head>
  <body>
    <header class="topbar">
      <a href="../">Back to demos</a>
      <button id="toggleMotion"></button>
    </header>

    <div id="scene"></div>
    <main>
      <section class="panel">
        <p class="label">Demo 12</p>
        <h1>3D Product Spotlight</h1>
        <p>Scroll to move camera rails around the product.</p>
      </section>
      <section class="panel"><h2>Material Focus</h2><p>Observe light and rotation changes.</p></section>
      <section class="panel"><h2>Hero Lock</h2><p>End at a composed front angle for CTA space.</p></section>
    </main>

    <script type="module" src="script.js"></script>
      </body>
</html>