Inspecting the Scene

Inspecting Materials, Meshes and the Scene Graph

Inspector V2 puts a Scene Explorer on the left: the node hierarchy (each bookcase with its books), lists of materials and textures, gizmos to move, turn and scale the selection, and a picker that selects what you click in the canvas. The right pane switches between Properties, Debug, Statistics, Creation Tools, Tools and Settings. Properties shows the selection's settings, live: a mesh has sections such as General (class, parent, bounding-box size), Transform, Display, Physics and Metadata; a material shows its colors and texture thumbnails, and a NodeMaterial gets a button that opens the Node Material Editor 89,603 on it. Debug switches textures, lights, shadows, fog, particles and post-processes off; Statistics counts draw calls, active meshes and faces, with frame times; Tools takes screenshots, records GIFs and exports .babylon or GLB files. When the picture is wrong, switch features off one at a time until the fault disappears.

An Inspector-style scene explorer and property pane built with the GUI: click a node or a mesh to inspect itHTMLLive
<!doctype html>
<style>
  body { margin: 0; background: #f7f3ec; font: 13px system-ui, sans-serif; color: #333; }
  canvas { width: 100%; max-width: 600px; height: 380px; display: block; touch-action: none; outline: none; }
</style>
<canvas id="view"></canvas>
<script src="https://cdn.jsdelivr.net/npm/babylonjs@9.28.0/babylon.js"></script>
<script src="https://cdn.jsdelivr.net/npm/babylonjs-gui@9.28.0/babylon.gui.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 real Inspector is a separate download (see the previous section). This page reads the same
// information straight from the scene: the node tree, a mesh's properties and frame statistics.
const canvas = document.getElementById('view');
const engine = new BABYLON.Engine(canvas, true, {}, true);
const scene = createScene(engine);
createRoom(scene);
const left = createBookcase(scene, 'bookcaseLeft', -1.8);
placeBooks(scene, left);
const camera = new BABYLON.ArcRotateCamera('browse', -1.6, 1.3, 5, new BABYLON.Vector3(-1.2, 1.2, 2), scene);
camera.minZ = 0.05;
camera.attachControl(canvas, true);
const stats = new BABYLON.SceneInstrumentation(scene);
const highlight = new BABYLON.HighlightLayer('selection', scene);

const GUI = BABYLON.GUI;
const ui = GUI.AdvancedDynamicTexture.CreateFullscreenUI('ui', true, scene);
ui.idealWidth = 600;
const pane = (left, width) => {
  const rect = Object.assign(new GUI.Rectangle(), { width: `${width}px`, height: '100%', left,
    background: 'rgba(255,255,255,0.92)', thickness: 0, horizontalAlignment: left.startsWith('-') ? 1 : 0 });
  ui.addControl(rect);
  const stack = Object.assign(new GUI.StackPanel(), { verticalAlignment: 0, paddingTop: '6px' });
  rect.addControl(stack);
  return stack;
};
const explorer = pane('0px', 150);                    // Scene Explorer on the left
const properties = pane('-0px', 190);                 // Properties on the right
const row = (stack, text, { size = 11, color = '#333', indent = 0, onClick } = {}) => {
  const block = Object.assign(new GUI.TextBlock('', text), { height: `${size + 6}px`, fontSize: size, color,
    textHorizontalAlignment: 0, paddingLeft: `${6 + indent * 10}px` });
  if (onClick) { block.isPointerBlocker = true; block.onPointerUpObservable.add(onClick); block.hoverCursor = 'pointer'; }
  stack.addControl(block);
  return block;
};

row(explorer, 'Scene Explorer', { size: 13, color: '#1f5f8b' });
const walk = (node, depth) => {                      // the node hierarchy, as the explorer shows it
  if (depth > 2 || node.name === 'part') return;
  row(explorer, `${node.getChildren().length ? '▾' : '·'} ${node.name}`, { indent: depth, onClick: () => select(node) });
  node.getChildren().forEach((child) => walk(child, depth + 1));
};
scene.rootNodes.filter((n) => !(n instanceof BABYLON.Light) && !(n instanceof BABYLON.Camera)).forEach((n) => walk(n, 0));

function select(node) {
  highlight.removeAllMeshes();
  if (node instanceof BABYLON.Mesh) highlight.addMesh(node, BABYLON.Color3.FromHexString('#ffe082'));
  properties.clearControls();
  row(properties, node.name, { size: 13, color: '#1f5f8b' });
  row(properties, `class ${node.getClassName()}`);
  row(properties, `parent ${node.parent?.name ?? '(none)'}`);
  if (node.getBoundingInfo) {
    const size = node.getBoundingInfo().boundingBox.extendSizeWorld.scale(2);
    row(properties, `size ${size.x.toFixed(2)} x ${size.y.toFixed(2)} x ${size.z.toFixed(2)} m`);
    row(properties, `vertices ${node.getTotalVertices()}`);
  }
  if (node.position) row(properties, `position ${node.position.x.toFixed(2)}, ${node.position.y.toFixed(2)}, ${node.position.z.toFixed(2)}`);
  if (node.material) {
    row(properties, `material ${node.material.name} (${node.material.getClassName()})`);
    const swatch = node.material.diffuseTexture ? 'diffuseTexture' : `diffuse ${node.material.diffuseColor?.toHexString()}`;
    row(properties, swatch);
  }
  if (node.metadata?.title) row(properties, `metadata.title "${node.metadata.title}"`);
}
scene.onPointerObservable.add(({ type, pickInfo }) => {   // the picker: click in the canvas
  if (type === BABYLON.PointerEventTypes.POINTERTAP && pickInfo?.pickedMesh) select(pickInfo.pickedMesh);
});
const statsText = row(ui, '', { size: 11 });
Object.assign(statsText, { verticalAlignment: 1, top: '-4px', left: '150px', width: '260px' });
scene.onAfterRenderObservable.add(() => {
  statsText.text = `Statistics: ${stats.drawCallsCounter.current} draw calls, ${scene.getActiveMeshes().length} active meshes`;
});
select(scene.getMeshByName('book3'));
engine.runRenderLoop(() => scene.render());
addEventListener('resize', () => engine.resize());
</script>