Uniforms live in UniformBuffer std140 blocks for the scene, each mesh, light and material (on WebGL 2, uniform buffer objects, UBO Layout). On WebGPU (Buffers and Bind Groups) the scene block is bind group 0, set once per pass, and each draw's resources group 1; bind groups and pipelines are cached by resource IDs and state. Continuing:
await new Promise((resolve) => setTimeout(resolve, 300)); // about 18 more frames
console.log(walnut.fragmentSourceCode.split('\n').filter((l) => /> (scene|mesh) :/.test(l))
.join('\n'));
const { WebGPUCacheBindGroups: groups, WebGPUCacheRenderPipeline: pipelines } = BABYLON;
console.log(`bind groups: ${groups.NumBindGroupsCreatedTotal} created, ` +
`${groups.NumBindGroupsCreatedLastFrame} in the last frame`);
console.log(`pipelines: ${pipelines.NumCacheMiss} created, ` +
`${pipelines.NumCacheHitWithoutHash} reused`);Output
@group(0) @binding(0) var<uniform> scene : Scene; @group(1) @binding(1) var<uniform> mesh : Mesh; bind groups: 6 created, 0 in the last frame pipelines: 2 created, 639 reused
Six draws built six bind groups on the first frame and none since, and two pipelines served every draw. Nonzero per-frame counters later mean something is rebuilt each frame.
<!doctype html>
<style>
body { margin: 0; background: #f7f3ec; font: 13px system-ui, sans-serif; color: #333; }
canvas { width: 100%; max-width: 600px; height: 280px; display: block; touch-action: none; outline: none; }
#info { max-width: 600px; margin: 0; padding: 4px 8px; font: 11px monospace; white-space: pre-wrap; }
</style>
<canvas id="view"></canvas>
<pre id="info">Starting WebGPU…</pre>
<script src="https://cdn.jsdelivr.net/npm/babylonjs@9.28.0/babylon.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 ----
const canvas = document.getElementById('view');
const info = document.getElementById('info');
(async () => {
if (!(await BABYLON.WebGPUEngine.IsSupportedAsync)) {
const g = canvas.getContext('2d');
canvas.width = 600; canvas.height = 280;
g.fillStyle = '#f7f3ec'; g.fillRect(0, 0, 600, 280);
g.fillStyle = '#b5452f'; g.font = '18px sans-serif'; g.textAlign = 'center';
g.fillText('WebGPU is not available in this browser', 300, 140);
info.textContent = 'WebGPU is not available in this browser.';
return;
}
const engine = new BABYLON.WebGPUEngine(canvas);
await engine.initAsync();
const scene = createScene(engine);
createRoom(scene);
placeBooks(scene, createBookcase(scene, 'bookcaseLeft', -1.8));
const camera = new BABYLON.ArcRotateCamera('browse', -1.7, 1.35, 4, new BABYLON.Vector3(-1.6, 1.1, 2.3), scene);
camera.attachControl(canvas, true);
engine.runRenderLoop(() => scene.render());
const { WebGPUCacheBindGroups: groups, WebGPUCacheRenderPipeline: pipelines } = BABYLON;
scene.executeWhenReady(() => {
const walnut = scene.getMeshByName('bookcaseLeft').subMeshes[0].effect;
// the scene block is bind group 0, set once per pass; each draw's own resources group 1
const blocks = walnut.fragmentSourceCode.split('\n').filter((l) => /(var<uniform>|struct) *(scene|mesh|Scene|Mesh)/i.test(l)).slice(0, 4);
scene.onAfterRenderObservable.add(() => {
info.textContent = `${blocks.join('\n')}\n` +
`bind groups: ${groups.NumBindGroupsCreatedTotal} created in all, ${groups.NumBindGroupsCreatedLastFrame} in the last frame\n` +
`pipelines: ${pipelines.NumCacheMiss} created, ${pipelines.NumCacheHitWithoutHash} reused`;
});
});
addEventListener('resize', () => engine.resize());
})().catch((error) => { info.textContent = `WebGPU failed: ${error.message}`; });
</script>