AssetContainer

The AssetContainer and addAllToScene

LoadAssetContainerAsync parses the file, creates its meshes, materials, textures and animation groups, and leaves them out of the scene in an AssetContainer. You decide when they appear, and can take them out again without reloading or losing the GPU resources:

Loading into a container, then adding and removing its assetsJavaScript
const container = await BABYLON.LoadAssetContainerAsync('booknest-books.glb', scene);
const count = (step) => console.log(`${step}: ${scene.meshes.length} meshes, ` +
  `${scene.materials.length} materials in the scene`);
count('loaded');
container.addAllToScene();                    // meshes, materials, textures, animations
count('added');
container.removeAllFromScene();               // still in memory, ready to add again
count('removed');
Output
loaded: 4 meshes, 2 materials in the scene
added: 11 meshes, 8 materials in the scene
removed: 4 meshes, 2 materials in the scene

Containers suit rooms and displays you swap in and out; dispose() frees one for good.

An AssetContainer of six books added to and removed from the scene without reloadingHTMLLive
<!doctype html>
<style>
  body { margin: 0; background: #f7f3ec; font: 13px system-ui, sans-serif; color: #333; }
  canvas { width: 100%; max-width: 600px; height: 300px; display: block; touch-action: none; outline: none; }
  #bar { max-width: 600px; display: flex; gap: 10px; align-items: center; padding: 6px 8px; } #log { max-width: 600px; margin: 0; padding: 0 8px; font-family: monospace; }
</style>
<canvas id="view"></canvas>
<div id="bar"><button id="toggle" disabled>Remove from scene</button></div><pre id="log"></pre>
<script src="https://cdn.jsdelivr.net/npm/babylonjs@9.28.0/babylon.js"></script>
<script src="https://cdn.jsdelivr.net/npm/babylonjs-loaders@9.28.0/babylonjs.loaders.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/babylonjs-serializers@9.28.0/babylonjs.serializers.min.js"></script>
<script>
// ---- BookNest's bookstore: the helpers the book keeps in bookstore.js ----
const ROOM = { width: 8, depth: 6, height: 3, wall: 0.15 };
const BOOKS = [
  { id: 1, title: 'The Quiet Harbor', author: 'Mara Ellison', color: '#1f5f8b', pages: 312, price: 14.99, rating: 4.6, inStock: true },
  { id: 2, title: 'Patterns of the Deep Web', author: 'Tomas Reyes', color: '#5b3f99', pages: 428, price: 32.5, rating: 4.4, inStock: true },
  { id: 3, title: 'Salt and Saffron', author: 'Priya Nair', color: '#e09a10', pages: 256, price: 24, rating: 4.8, inStock: false },
  { id: 4, title: 'Small Steps to Big Summits', author: 'Dana Whitfield', color: '#3f7d3a', pages: 198, price: 18.5, rating: 4.3, inStock: true },
  { id: 5, title: "The Clockmaker's Paradox", author: 'Julian Voss', color: '#b5452f', pages: 344, price: 16.75, rating: 4.7, inStock: true },
  { id: 6, title: 'Gardens in Glass', author: 'Lena Hart', color: '#2a9d8f', pages: 176, price: 21.3, rating: 4.5, inStock: true },
];
function createScene(engine) {
  const scene = new BABYLON.Scene(engine);
  scene.clearColor = BABYLON.Color4.FromHexString('#cfd8dcff');
  const sky = new BABYLON.HemisphericLight('sky', new BABYLON.Vector3(0.3, 1, -0.4), scene);
  sky.groundColor = new BABYLON.Color3(0.35, 0.32, 0.3);
  return scene;
}
function paint(scene, name, hex) {                  // a matte color
  const material = new BABYLON.StandardMaterial(name, scene);
  material.diffuseColor = BABYLON.Color3.FromHexString(hex);
  material.specularColor = BABYLON.Color3.Black();
  return material;
}
function createRoom(scene) {                        // floor and three walls, front open
  const room = new BABYLON.TransformNode('room', scene);
  const floor = BABYLON.MeshBuilder.CreateGround('floor', { width: ROOM.width, height: ROOM.depth }, scene);
  floor.material = paint(scene, 'oak', '#b08d6a');
  floor.parent = room;
  const plaster = paint(scene, 'plaster', '#fff3e0');
  for (const [name, width, x, z] of [['backWall', 8, 0, 3], ['leftWall', 6, -4, 0], ['rightWall', 6, 4, 0]]) {
    const wall = BABYLON.MeshBuilder.CreateBox(name, { width, height: ROOM.height, depth: ROOM.wall }, scene);
    wall.position.set(x, ROOM.height / 2, z);
    wall.rotation.y = x ? Math.PI / 2 : 0;
    wall.material = plaster;
    wall.parent = room;
  }
  return room;
}
function createBookcase(scene, name, x) {           // 8 boxes merged into 1 mesh
  const [w, h, d, t] = [3, 2.2, 0.35, 0.04];
  const parts = [[t, h, d, -w / 2, h / 2, 0], [t, h, d, w / 2, h / 2, 0], [w, h, t, 0, h / 2, d / 2 - t / 2]];
  for (let i = 0; i < 5; i++) parts.push([w, t, d, 0, 0.1 + i * 0.5, 0]);
  const bookcase = BABYLON.Mesh.MergeMeshes(parts.map(([width, height, depth, px, py, pz]) => {
    const part = BABYLON.MeshBuilder.CreateBox('part', { width, height, depth }, scene);
    part.position.set(px, py, pz);
    return part;
  }), true);
  bookcase.name = name;
  bookcase.material = paint(scene, 'walnut', '#6d4c33');
  bookcase.position.set(x, 0, ROOM.depth / 2 - ROOM.wall / 2 - d / 2);   // against the back wall
  return bookcase;
}
function drawCover(scene, book) {                   // cover art painted on a canvas
  const tex = new BABYLON.DynamicTexture('cover' + book.id, { width: 256, height: 384 }, scene);
  const c = tex.getContext();
  c.fillStyle = book.color; c.fillRect(0, 0, 256, 384);
  c.fillStyle = 'rgba(0,0,0,0.4)'; c.fillRect(0, 0, 18, 384);         // the dark left edge
  c.strokeStyle = '#fff8e1'; c.lineWidth = 3; c.strokeRect(34, 24, 202, 336);
  c.fillStyle = '#fff8e1'; c.textAlign = 'center'; c.font = 'bold 30px Georgia';
  const lines = [''];
  for (const word of book.title.split(' ')) {
    const test = (lines[lines.length - 1] + ' ' + word).trim();
    if (c.measureText(test).width > 180) lines.push(word); else lines[lines.length - 1] = test;
  }
  lines.forEach((line, i) => c.fillText(line, 135, 110 + i * 38));
  c.font = '20px Georgia'; c.fillText(book.author, 135, 330);
  tex.update();
  return tex;
}
function placeBooks(scene, bookcase, shelf = 2) {   // six books, spines out, covers on +x
  const strip = new BABYLON.Vector4(0, 0, 0.07, 1);
  const faceUV = [strip, strip, new BABYLON.Vector4(0, 0, 1, 1), strip, strip, strip];
  let x = -0.35;                                    // left end of the row, local to the bookcase
  return BOOKS.map((record) => {
    const width = record.pages / 4000 + 0.02;       // spine thickness from page count
    const book = BABYLON.MeshBuilder.CreateBox(`book${record.id}`, { width, height: 0.3, depth: 0.22, faceUV, wrap: true }, scene);
    book.parent = bookcase;
    book.position.set(x + width / 2, 0.12 + shelf * 0.5 + 0.15, -0.02);
    x += width + 0.012;
    book.material = new BABYLON.StandardMaterial(record.title, scene);
    book.material.diffuseTexture = drawCover(scene, record);
    book.material.specularColor = new BABYLON.Color3(0.15, 0.15, 0.15);
    book.metadata = record;                         // the record, for picking
    return book;
  });
}
// The book cuts the storefront with CSG2 (Manifold WebAssembly); this sandbox cannot download
// the .wasm, so the older pure-JavaScript BABYLON.CSG makes the same cuts here.
function createFrontWall(scene) {
  const box = (width, height, depth, x, y) => {
    const mesh = BABYLON.MeshBuilder.CreateBox('cut', { width, height, depth }, scene);
    mesh.position.set(x, y, -ROOM.depth / 2);
    return mesh;
  };
  const solid = box(ROOM.width, ROOM.height, ROOM.wall, 0, ROOM.height / 2);
  const windowHole = box(3.2, 1.6, 1, -1.4, 1.6), doorHole = box(1.1, 2.2, 1, 2.3, 1.1);
  const wall = BABYLON.CSG.FromMesh(solid).subtract(BABYLON.CSG.FromMesh(windowHole))
    .subtract(BABYLON.CSG.FromMesh(doorHole)).toMesh('frontWall', scene.getMaterialByName('plaster'), scene);
  [solid, windowHole, doorHole].forEach((mesh) => mesh.dispose());
  return wall;
}
// ---- end of the bookstore helpers ----

// The book loads booknest-books.glb over HTTP. This sandboxed preview cannot fetch files, so it
// first writes the same GLB in memory (six books with PBR covers and their records as glTF
// extras) with the serializers package, then hands those bytes to the loader.
async function createBooksGlb(engine) {
  const scratch = new BABYLON.Scene(engine);
  const shelf = new BABYLON.TransformNode('shelf', scratch);     // a parent that is not exported
  const books = placeBooks(scratch, shelf, 0);                  // shelf 0: books stand at y 0.27
  books.forEach((book) => {                                     // PBR covers -> glTF materials
    const cover = new BABYLON.PBRMaterial(book.material.name, scratch);
    Object.assign(cover, { albedoTexture: book.material.diffuseTexture, metallic: 0, roughness: 0.5 });
    book.material = cover;
  });
  await scratch.whenReadyAsync();
  const glb = await BABYLON.GLTF2Export.GLBAsync(scratch, 'booknest-books', {
    shouldExportNode: (node) => node.name.startsWith('book'),   // the six books only
    metadataSelector: (metadata) => metadata,                   // BOOKS[i] -> glTF extras
  });
  const bytes = new Uint8Array(await glb.files['booknest-books.glb'].arrayBuffer());
  scratch.dispose();
  return bytes;                                                 // pass with { pluginExtension: '.glb' }
}

const canvas = document.getElementById('view');
const engine = new BABYLON.Engine(canvas, true, {}, true);
const scene = createScene(engine);
createRoom(scene);
const bookcase = createBookcase(scene, 'bookcase', 0);
const camera = new BABYLON.ArcRotateCamera('cam', -Math.PI / 2, 1.3, 3.2, new BABYLON.Vector3(0, 1.2, 2.3), scene);
camera.minZ = 0.05;
camera.attachControl(canvas, true);
engine.runRenderLoop(() => scene.render());
const log = document.getElementById('log');
const count = (step) => {
  log.textContent += `${step.padEnd(8)} ${scene.meshes.length} meshes, ${scene.materials.length} materials in the scene\n`;
};

(async () => {
  const bytes = await createBooksGlb(engine);
  // Parse the file and create everything, but leave it out of the scene
  const container = await BABYLON.LoadAssetContainerAsync(bytes, scene, { pluginExtension: '.glb' });
  const root = container.meshes[0];
  root.parent = bookcase;
  root.position.set(0, 1, 0);                        // from shelf 0 in the file to shelf 2
  count('loaded');
  container.addAllToScene();                         // meshes, materials, textures, animations
  count('added');
  const button = document.getElementById('toggle');
  button.disabled = false;
  let inScene = true;
  button.addEventListener('click', () => {
    if (inScene) container.removeAllFromScene();     // still in memory, ready to add again
    else container.addAllToScene();
    inScene = !inScene;
    count(inScene ? 'added' : 'removed');
    button.textContent = inScene ? 'Remove from scene' : 'Add to scene';
  });
})();
addEventListener('resize', () => engine.resize());
</script>