3D viewer: switch STEP engine to occt-wasm (OCCT V8, module worker); fix mobile rendering (Uint16 chunking, index wrapping, tight near/far); state-coloured box + debug line; app widget parity; licenses/docs

AGENTS.md

@@ -95,16 +95,25 @@ set the other labels, and set `publish=true` **last**.
 - **3D models** (`scripts/3d_model_viewer.js`): renders `.step`/`.stp`/`.stl` as file notes
   (title ends in the extension), inline attachment links, or links to published model file
   notes from text notes (resolved via `window.blogData`). The viewer is **full-bleed**
-  (`~100vw`, `height: min(70vh, 900px)`, ResizeObserver), with a loading progress bar and a
+  (`~100vw`, `height: min(70vh, 900px)`, ResizeObserver), with a loading progress bar, a
-  caption that always shows `name · size · triangle count`. STEP is parsed by occt-import-js
+  caption that shows `name · size · triangle count`, and a **debug line** under the box that
-  (OpenCascade WASM) in a **Web Worker** (non-blocking) with
+  logs the step (`loading`/`parsing`/`done`/`error`) for on-device diagnosis. STEP is parsed
-  `linearDeflection: 0.0002, angularDeflection: 0.1`. Libraries hosted as local notes via
+  by **occt-wasm** (OpenCASCADE **V8**, MIT/Apache-2.0) in a **module worker**
+  (`new Worker(url, {type:"module"})`, non-blocking) with
+  `linearDeflection: 0.4, angularDeflection: 0.2`. Libraries hosted as local notes via
   `__THREE_ID__`/`__THREE_ORBIT_ID__`/`__THREE_STL_ID__`/`__OCCT_JS_ID__`/`__OCCT_WASM_ID__`.
   User guide: `docs/embed-3d-model.md`.
+  - **Mobile gotchas (both were real bugs)**: (1) mesh >65535 vertices must be split into
+    chunks with `Uint16` indices (`chunkGeometry`) or mobile GPUs without
+    `OES_element_index_uint` render nothing; (2) `geometry.setIndex(rawTypedArray)` in
+    three r128 leaves `geometry.index` WITHOUT `.count` → always wrap:
+    `setIndex(new THREE.BufferAttribute(index, 1))`; (3) tighten camera `near`/`far` from the
+    model size after `fit()` (`near=d·0.05, far=d·10`) for 16-bit depth buffers.
 - **3D viewer in the Trilium app** (independent of the blog): `app/3d-model-viewer-app.jsx`
   (widget, `#widget=3dModelViewer`, `parent: note-detail-pane`) + `app/3d-worker.js` (STEP
-  worker, loaded from a code note instead of a Blob so the app CSP allows it). The widget
+  module worker that imports the occt-wasm bundle from a code note, so it works under the
-  renders the viewer for file notes whose title ends in `.step`/`.stp`/`.stl`.
+  app's CSP). The widget renders the viewer for file notes whose title ends in
+  `.step`/`.stp`/`.stl`.
 - Images in the share are served full-size only (no resize endpoint) → keep the
   `_thumb` child-note convention for small thumbnails.
 - Built-in share footer navigation and book children list are hidden

README.md

@@ -46,12 +46,12 @@ no external dependencies (except `highlight.js`, vendored in `lib/`).
 - **Widget rendering** for Mermaid, Excalidraw (canvas) and MindElixir (mind map) notes, with a
   collapsible, highlighted "Source" block and copy button.
 - **3D models**: `.step` / `.stp` / `.stl` files (as file notes, as inline attachments, or linked
-  from text notes) render in an interactive three.js viewer (STEP via occt-import-js, OpenCascade
+  from text notes) render in an interactive three.js viewer (STEP via **occt-wasm**, OpenCASCADE
-  WASM, parsed in a **Web Worker** so the page stays responsive). The viewer is **full-bleed**
+  V8, parsed in a non-blocking **module worker**). The viewer is **full-bleed** (~`100vw`) with a
-  (~`100vw`) with a viewport-based height, drag to rotate / scroll to zoom, rounded 8px box, a
+  viewport-based height, drag to rotate / scroll to zoom, rounded 8px box, a loading progress bar,
-  loading progress bar and a caption that always shows `name · size · triangle count`.
+  a caption showing `name · size · triangle count`, and a small debug line. Large meshes are
-  STEP tessellation is dense (≈0.1–1 M+ triangles for assemblies). See
+  split into `Uint16` chunks so mobile GPUs render them too (≈480k triangles for the demo
-  [docs/embed-3d-model.md](docs/embed-3d-model.md).
+  battery module). See [docs/embed-3d-model.md](docs/embed-3d-model.md).
 - **3D viewer inside Trilium (app widget)**: the same viewer runs in the Trilium app itself
   (independent of the blog) via a `note-detail-pane` widget – see `app/`.
 - Code highlighting (highlight.js + line numbers) and copy buttons on all code boxes.
@@ -69,7 +69,7 @@ no external dependencies (except `highlight.js`, vendored in `lib/`).
 | `theme/favicon.svg` | default site favicon | code (SVG) |
 | `theme/cookie.woff2` | "Cookie" font for the Buy me a coffee button | file, `font/woff2` |
 | `lib/highlight.js` | vendored highlight.js | code, `application/javascript` |
-| `lib/3d/*` | three.js + OrbitControls + STLLoader + occt-import-js (WASM) for the 3D viewer | code / file |
+| `lib/3d/*` | three.js + OrbitControls + STLLoader + occt-wasm (OCCT V8 bundle + WASM) for the 3D viewer | code / file |
 | `lib/hljs_line_numbers.js` | highlight.js line-numbers plugin | code |
 | `scripts/*.js` | frontend share snippets (content is pasted **verbatim** into a code note, including the `<script>`/`<style>` wrapper) | code |
 | `app/3d-model-viewer-app.jsx` | JSX widget that renders the 3D viewer for model file notes inside the Trilium app (label `#widget=3dModelViewer`) | code, `text/jsx` |

THIRD_PARTY_LICENSES.md

@@ -11,6 +11,7 @@ The following files in this repository are **not** covered by the GPL-3.0 and ke
 | `assets/palette.png` | Gruvbox palette image from [morhetz/gruvbox](https://github.com/morhetz/gruvbox) (repo: MIT) | [MIT](#mit-license) |
 | `lib/3d/three.min.js`, `lib/3d/OrbitControls.js`, `lib/3d/STLLoader.js` | [three.js](https://github.com/mrdoob/three.js) r128 | [MIT](#mit-license) |
 | `lib/3d/occt-import-js.js`, `lib/3d/occt-import-js.wasm` | [occt-import-js](https://github.com/kovacsv/occt-import-js) (OpenCASCADE, WASM) | [LGPL-2.1](#lgpl-21) |
+| `lib/3d/occt-wasm-bundle.js`, `lib/3d/occt-wasm.wasm` | [occt-wasm](https://github.com/andymai/occt-wasm) (OpenCASCADE **OCCT V8**, WebAssembly, esbuild-bundled `OcctKernel`) | [MIT OR Apache-2.0](#mit-license) |
 | `scripts/bmc_button.js` | embeds the Trilium logo (SVG) from [Trilium/TriliumNext](https://github.com/TriliumNext/Trilium) | [AGPL-3.0](https://www.gnu.org/licenses/agpl-3.0.txt) |
 
 ## BSD-3-Clause
@@ -84,6 +85,10 @@ Copyright (c) 2011 by Ania Kruk, with Reserved Font Name "Cookie".
 (<https://www.gnu.org/licenses/old-licenses/lgpl-2.1.html>). OpenCASCADE is LGPL-2.1 as well;
 the WASM blob is loaded at runtime by `scripts/3d_model_viewer.js` and is not statically linked.
 
+> Note: the 3D viewer now uses **`occt-wasm`** (OCCT V8, MIT/Apache-2.0) instead of
+> `occt-import-js` as its STEP engine. The `occt-import-js` files are kept for reference /
+> fallback only.
+
 ## AGPL-3.0
 
 The Trilium logo embedded in `scripts/bmc_button.js` belongs to the Trilium /

app/3d-model-viewer-app.jsx

@@ -7,7 +7,7 @@ const OCCT_JS = "api/notes/__OCCT_JS_ID__/download";
 const OCCT_WASM = "api/notes/__OCCT_WASM_ID__/download";
 const WORKER_URL = "api/notes/__3D_WORKER_ID__/download";
 
-const STEP_PARAMS = { linearDeflection: 0.0002, angularDeflection: 0.1 };
+const STEP_PARAMS = { linearDeflection: 0.4, angularDeflection: 0.2 };
 
 const WORKER_ABS = new URL(WORKER_URL, location.href).href;
 const OCCT_JS_ABS = new URL(OCCT_JS, location.href).href;
@@ -24,6 +24,66 @@ function formatCount(n) {
     if (n >= 1000) return (n / 1000).toFixed(1) + "k";
     return String(n);
 }
+function fixWinding(geo) {
+    if (geo.index) return;
+    var pos = geo.attributes.position;
+    var count = pos.count;
+    geo.computeBoundingBox();
+    var center = geo.boundingBox.getCenter(new THREE.Vector3());
+    var vA = new THREE.Vector3(), vB = new THREE.Vector3(), vC = new THREE.Vector3();
+    var e1 = new THREE.Vector3(), e2 = new THREE.Vector3(), n = new THREE.Vector3(), toC = new THREE.Vector3();
+    var p = pos.array;
+    for (var i = 0; i < count; i += 3) {
+        vA.fromBufferAttribute(pos, i); vB.fromBufferAttribute(pos, i + 1); vC.fromBufferAttribute(pos, i + 2);
+        e1.subVectors(vB, vA); e2.subVectors(vC, vA); n.crossVectors(e1, e2);
+        toC.subVectors(center, vA);
+        if (n.dot(toC) > 0) {
+            var x = (i + 1) * 3, y = (i + 2) * 3;
+            var t;
+            t = p[x]; p[x] = p[y]; p[y] = t;
+            t = p[x + 1]; p[x + 1] = p[y + 1]; p[y + 1] = t;
+            t = p[x + 2]; p[x + 2] = p[y + 2]; p[y + 2] = t;
+        }
+    }
+    pos.needsUpdate = true;
+}
+function chunkGeometry(geo, group, mat) {
+    var pos = geo.attributes.position;
+    var idx = geo.index;
+    var maxVerts = 65000;
+    if (!idx || pos.count <= maxVerts) {
+        geo.computeVertexNormals();
+        group.add(new THREE.Mesh(geo, mat));
+        return;
+    }
+    var triCount = idx.count / 3;
+    var t = 0;
+    while (t < triCount) {
+        var vmap = new Map();
+        var vpos = [];
+        var iarr = [];
+        while (t < triCount && vmap.size < maxVerts - 3) {
+            var a = idx.getX(t * 3), b = idx.getX(t * 3 + 1), c = idx.getX(t * 3 + 2);
+            var ids = [a, b, c];
+            for (var k = 0; k < 3; k++) {
+                var id = ids[k];
+                var loc = vmap.get(id);
+                if (loc === undefined) {
+                    loc = vpos.length / 3;
+                    vmap.set(id, loc);
+                    vpos.push(pos.getX(id), pos.getY(id), pos.getZ(id));
+                }
+                iarr.push(loc);
+            }
+            t++;
+        }
+        var g = new THREE.BufferGeometry();
+        g.setAttribute("position", new THREE.Float32BufferAttribute(vpos, 3));
+        g.setIndex(new THREE.BufferAttribute(new Uint16Array(iarr), 1));
+        g.computeVertexNormals();
+        group.add(new THREE.Mesh(g, mat));
+    }
+}
 function loadScript(src, cb) {
     var s = document.createElement("script");
     s.src = src;
@@ -203,6 +263,9 @@ function initViewer(el, url, ext) {
             camera.position.set(center.x + d * 0.9, center.y + d * 0.6, center.z + d);
             controls.target.copy(center);
             controls.update();
+            camera.near = d * 0.05;
+            camera.far = d * 10;
+            camera.updateProjectionMatrix();
         }
         function showCanvas() {
             wrap.innerHTML = "";
@@ -225,26 +288,23 @@ function initViewer(el, url, ext) {
                     setStatus("Parsing STEP\u2026");
                     setProgress(null);
                     var t0 = Date.now();
-                    var parseTimer = setInterval(function () { setStatus("Parsing STEP\u2026 (" + Math.round((Date.now() - t0) / 1000) + "s)"); }, 1000);
+                    var parseTimer = setInterval(function () {
-                    var worker = new Worker(WORKER_ABS);
+                        var el = Date.now() - t0;
+                        setStatus("Parsing STEP\u2026 (" + Math.round(el / 1000) + "s)");
+                        if (el > 240000 && !settled) { worker.terminate(); clearInterval(parseTimer); onError("STEP parse timed out."); }
+                    }, 1000);
+                    var worker = new Worker(WORKER_ABS, { type: "module" });
                     var settled = false;
                     worker.onmessage = function (e) {
-                        if (e.data.type === "ready") {
+                        if (e.data.type === "done") {
-                            worker.postMessage({ type: "parse", data: data, params: STEP_PARAMS }, [data.buffer]);
-                        } else if (e.data.type === "done") {
                             settled = true; worker.terminate(); clearInterval(parseTimer);
-                            if (!e.data.success) { onError("Could not parse STEP file."); return; }
-                            var tris = 0;
-                            (e.data.meshes || []).forEach(function (m) {
                             var geo = new THREE.BufferGeometry();
-                                geo.setAttribute("position", new THREE.Float32BufferAttribute(m.position, 3));
+                            geo.setAttribute("position", new THREE.Float32BufferAttribute(e.data.positions, 3));
-                                if (m.index) geo.setIndex(m.index);
+                            if (e.data.indices) geo.setIndex(new THREE.BufferAttribute(e.data.indices, 1));
-                                geo.computeVertexNormals();
+                            fixWinding(geo);
-                                var color = m.color && m.color.length === 3 ? new THREE.Color(m.color[0], m.color[1], m.color[2]) : null;
+                            var mat = new THREE.MeshStandardMaterial({ color: 0xb8bb26, metalness: 0.2, roughness: 0.6, side: THREE.DoubleSide, flatShading: true });
-                                var mat = new THREE.MeshStandardMaterial({ color: color || 0xb8bb26, metalness: 0.2, roughness: 0.6, side: THREE.DoubleSide, flatShading: true });
+                            chunkGeometry(geo, group, mat);
-                                group.add(new THREE.Mesh(geo, mat));
+                            var tris = (e.data.indices && e.data.indices.length) ? e.data.indices.length / 3 : e.data.positions.length / 9;
-                                tris += geo.index ? geo.index.count / 3 : geo.attributes.position.count / 3;
-                            });
                             fit();
                             showCanvas();
                             showData(formatCount(tris) + " triangles");
@@ -256,7 +316,7 @@ function initViewer(el, url, ext) {
                     worker.onerror = function (e) {
                         if (!settled) { settled = true; worker.terminate(); clearInterval(parseTimer); onError("STEP worker error: " + (e && e.message || "unknown")); }
                     };
-                    worker.postMessage({ type: "loadLib", libUrl: OCCT_JS_ABS, wasm: new Uint8Array(wasmBuf) }, [wasmBuf]);
+                    worker.postMessage({ type: "parse", data: data, params: STEP_PARAMS, wasm: new Uint8Array(wasmBuf) }, [data.buffer, wasmBuf]);
                 }).catch(function () { onError("Could not download STEP parser."); });
             } else {
                 var geo = new THREE.STLLoader().parse(data.buffer);

app/3d-worker.js

@@ -1,38 +1,17 @@
-self.onmessage = function (e) {
+import { OcctKernel } from "https://YOUR-INSTANCE.example.com/api/notes/__OCCT_JS_ID__/download";
+let kernel = null;
+let initP = null;
+self.onmessage = async function (e) {
     var d = e.data;
-    if (d.type === 'loadLib') {
+    if (d.type !== "parse") return;
-        try { importScripts(d.libUrl); } catch (err) {
-            self.postMessage({ type: 'error', message: 'importScripts: ' + (err && err.message || err) }); return;
-        }
-        if (typeof self.occtimportjs !== 'function') {
-            self.postMessage({ type: 'error', message: 'STEP parser not found.' }); return;
-        }
-        self.occtimportjs({ locateFile: function () { return 'occt.wasm'; }, wasmBinary: d.wasm }).then(function (occt) {
-            self.occt = occt;
-            self.postMessage({ type: 'ready' });
-        }).catch(function (err) {
-            self.postMessage({ type: 'error', message: 'STEP init: ' + (err && err.message || err) });
-        });
-        return;
-    }
-    if (d.type === 'parse' && self.occt) {
     try {
-            var result = self.occt.ReadStepFile(d.data, d.params);
+        if (!initP) initP = OcctKernel.init({ wasm: d.wasm });
-            var meshes = [];
+        kernel = await initP;
-            (result.meshes || []).forEach(function (m) {
+        var shape = kernel.importStep(d.data);
-                if (!m.attributes || !m.attributes.position) return;
+        var mesh = kernel.tessellate(shape, d.params);
-                var out = { position: m.attributes.position.array, color: m.color };
+        kernel.release(shape);
-                if (m.attributes.index && m.attributes.index.array) out.index = m.attributes.index.array;
+        self.postMessage({ type: "done", positions: mesh.positions, normals: mesh.normals, indices: mesh.indices }, [mesh.positions.buffer, mesh.normals.buffer, mesh.indices.buffer]);
-                meshes.push(out);
-            });
-            var transfer = [];
-            meshes.forEach(function (m) {
-                if (m.position && m.position.buffer) transfer.push(m.position.buffer);
-                if (m.index && m.index.buffer) transfer.push(m.index.buffer);
-            });
-            self.postMessage({ type: 'done', success: !!result.success, meshes: meshes }, transfer);
     } catch (err) {
-            self.postMessage({ type: 'error', message: 'parse: ' + (err && err.message || err) });
+        self.postMessage({ type: "error", message: "parse: " + (err && err.message || err) });
-        }
     }
 };

docs/embed-3d-model.md

@@ -40,10 +40,11 @@ exists as its own (published) file note — the model stays in one place.
    You can embed several models per post this way.
 
 > Tip: STL (plain triangle meshes) is rendered with three.js only; STEP (CAD B-rep) is
-> parsed by occt-import-js (OpenCASCADE WASM, LGPL-2.1) in a **Web Worker** (non-blocking).
+> parsed by **occt-wasm** (OpenCASCADE **V8**, WASM, MIT/Apache-2.0) in a **Web Worker**
-> The first STEP view downloads the ~7.6 MB WASM once and then caches it in the browser.
+> (module worker, non-blocking). The first STEP view downloads the ~22 MB WASM once and
-> STEP tessellation is set to `linearDeflection: 0.0002, angularDeflection: 0.1`
+> then caches it in the browser.
-> (dense meshes, typically a few hundred k to >1 M triangles for assemblies).
+> STEP tessellation is set to `linearDeflection: 0.4, angularDeflection: 0.2`
+> (≈480k triangles for the ignis battery module; tuned for mobile).
 
 ## Requirements
 
@@ -51,8 +52,15 @@ exists as its own (published) file note — the model stays in one place.
   (inheritable) on the blog root, `shareHtmlLocation=body:end`.
 - The five libraries must exist as notes and be referenced by the script via the
   placeholder tokens in `scripts/3d_model_viewer.js`:
-  `__THREE_ID__`, `__THREE_ORBIT_ID__`, `__THREE_STL_ID__`, `__OCCT_JS_ID__`,
+  `__THREE_ID__`, `__THREE_ORBIT_ID__`, `__THREE_STL_ID__`, `__OCCT_JS_ID__`
-  `__OCCT_WASM_ID__` (see the README installation for the note titles).
+  (the occt-wasm **bundle**), `__OCCT_WASM_ID__` (occt-wasm.wasm) – see the README
+  installation for the note titles. The STEP worker is a **module worker** (`type: "module"`),
+  so the browser must support ES modules in workers (all modern browsers).
+- **Mobile compatibility**: the mesh is split into chunks of ≤65000 vertices
+  (`chunkGeometry`, `Uint16` indices) so it renders on GPUs without
+  `OES_element_index_uint`; the camera near/far is tightened after `fit()` for 16-bit
+  depth buffers. The caption always shows a small **debug line** with the current step
+  (`loading` / `parsing` / `done` / `error`) – useful while diagnosing.
 - For **inline embedding from a file note (Option C)** the `blog_data` note must be
   present and the target model must be a published article (the viewer resolves
   `./<alias>` links against `window.blogData`).

scripts/3d_model_viewer.js

@@ -11,46 +11,24 @@
 
     var MODEL_RE = /\.(stl|step|stp)$/i;
 
-    var STEP_PARAMS = { linearDeflection: 0.0002, angularDeflection: 0.1 };
+    var STEP_PARAMS = { linearDeflection: 0.4, angularDeflection: 0.2 };
 
     var WORKER_SRC = [
-        "self.onmessage = function (e) {",
+        'import { OcctKernel } from "' + OCCT_JS_ABS + '";',
+        "let kernel = null; let initP = null;",
+        "self.onmessage = async function (e) {",
         "    var d = e.data;",
-        "    if (d.type === 'loadLib') {",
+        "    if (d.type !== 'parse') return;",
-        "        try { importScripts(d.libUrl); } catch (err) {",
-        "            self.postMessage({ type: 'error', message: 'importScripts: ' + (err && err.message || err) }); return;",
-        "        }",
-        "        if (typeof self.occtimportjs !== 'function') {",
-        "            self.postMessage({ type: 'error', message: 'STEP parser not found.' }); return;",
-        "        }",
-        "        self.occtimportjs({ locateFile: function () { return 'occt.wasm'; }, wasmBinary: d.wasm }).then(function (occt) {",
-        "            self.occt = occt;",
-        "            self.postMessage({ type: 'ready' });",
-        "        }).catch(function (err) {",
-        "            self.postMessage({ type: 'error', message: 'STEP init: ' + (err && err.message || err) });",
-        "        });",
-        "        return;",
-        "    }",
-        "    if (d.type === 'parse' && self.occt) {",
         "    try {",
-        "            var result = self.occt.ReadStepFile(d.data, d.params);",
+        "        if (!initP) initP = OcctKernel.init({ wasm: d.wasm });",
-        "            var meshes = [];",
+        "        kernel = await initP;",
-        "            (result.meshes || []).forEach(function (m) {",
+        "        var shape = kernel.importStep(d.data);",
-        "                if (!m.attributes || !m.attributes.position) return;",
+        "        var mesh = kernel.tessellate(shape, d.params);",
-        "                var out = { position: m.attributes.position.array, color: m.color };",
+        "        kernel.release(shape);",
-        "                if (m.attributes.index && m.attributes.index.array) out.index = m.attributes.index.array;",
+        "        self.postMessage({ type: 'done', positions: mesh.positions, normals: mesh.normals, indices: mesh.indices }, [mesh.positions.buffer, mesh.normals.buffer, mesh.indices.buffer]);",
-        "                meshes.push(out);",
-        "            });",
-        "            var transfer = [];",
-        "            meshes.forEach(function (m) {",
-        "                if (m.position && m.position.buffer) transfer.push(m.position.buffer);",
-        "                if (m.index && m.index.buffer) transfer.push(m.index.buffer);",
-        "            });",
-        "            self.postMessage({ type: 'done', success: !!result.success, meshes: meshes }, transfer);",
         "    } catch (err) {",
         "        self.postMessage({ type: 'error', message: 'parse: ' + (err && err.message || err) });",
         "    }",
-        "    }",
         "};"
     ].join("\n");
 
@@ -67,6 +45,68 @@
         return String(n);
     }
 
+    function fixWinding(geo) {
+        if (geo.index) return;
+        var pos = geo.attributes.position;
+        var count = pos.count;
+        geo.computeBoundingBox();
+        var center = geo.boundingBox.getCenter(new THREE.Vector3());
+        var vA = new THREE.Vector3(), vB = new THREE.Vector3(), vC = new THREE.Vector3();
+        var e1 = new THREE.Vector3(), e2 = new THREE.Vector3(), n = new THREE.Vector3(), toC = new THREE.Vector3();
+        var p = pos.array;
+        for (var i = 0; i < count; i += 3) {
+            vA.fromBufferAttribute(pos, i); vB.fromBufferAttribute(pos, i + 1); vC.fromBufferAttribute(pos, i + 2);
+            e1.subVectors(vB, vA); e2.subVectors(vC, vA); n.crossVectors(e1, e2);
+            toC.subVectors(center, vA);
+            if (n.dot(toC) > 0) {
+                var x = (i + 1) * 3, y = (i + 2) * 3;
+                var t;
+                t = p[x]; p[x] = p[y]; p[y] = t;
+                t = p[x + 1]; p[x + 1] = p[y + 1]; p[y + 1] = t;
+                t = p[x + 2]; p[x + 2] = p[y + 2]; p[y + 2] = t;
+            }
+        }
+        pos.needsUpdate = true;
+    }
+
+    function chunkGeometry(geo, group, mat) {
+        var pos = geo.attributes.position;
+        var idx = geo.index;
+        var maxVerts = 65000;
+        if (!idx || pos.count <= maxVerts) {
+            geo.computeVertexNormals();
+            group.add(new THREE.Mesh(geo, mat));
+            return;
+        }
+        var triCount = idx.count / 3;
+        var t = 0;
+        while (t < triCount) {
+            var vmap = new Map();
+            var vpos = [];
+            var iarr = [];
+            while (t < triCount && vmap.size < maxVerts - 3) {
+                var a = idx.getX(t * 3), b = idx.getX(t * 3 + 1), c = idx.getX(t * 3 + 2);
+                var ids = [a, b, c];
+                for (var k = 0; k < 3; k++) {
+                    var id = ids[k];
+                    var loc = vmap.get(id);
+                    if (loc === undefined) {
+                        loc = vpos.length / 3;
+                        vmap.set(id, loc);
+                        vpos.push(pos.getX(id), pos.getY(id), pos.getZ(id));
+                    }
+                    iarr.push(loc);
+                }
+                t++;
+            }
+            var g = new THREE.BufferGeometry();
+            g.setAttribute("position", new THREE.Float32BufferAttribute(vpos, 3));
+            g.setIndex(new THREE.BufferAttribute(new Uint16Array(iarr), 1));
+            g.computeVertexNormals();
+            group.add(new THREE.Mesh(g, mat));
+        }
+    }
+
     function makeViewer(name) {
         var box = document.createElement("div");
         box.className = "model-viewer";
@@ -92,6 +132,9 @@
             cap.textContent = name;
             box.appendChild(cap);
         }
+        var dbg = document.createElement("div");
+        dbg.className = "model-viewer-debug";
+        box.appendChild(dbg);
         return box;
     }
 
@@ -135,6 +178,11 @@
             var s = el.querySelector(".model-viewer-status");
             if (s) s.textContent = text;
         }
+        function setStep(state, msg) {
+            el.className = "model-viewer model-" + state;
+            var dbg = el.querySelector(".model-viewer-debug");
+            if (dbg) dbg.textContent = new Date().toLocaleTimeString() + " [" + state + "] " + msg;
+        }
         function setProgress(percent) {
             var bar = el.querySelector(".model-viewer-progress-fill");
             if (!bar) return;
@@ -150,6 +198,7 @@
             var s = el.querySelector(".model-viewer-status");
             if (s) { s.textContent = msg || "Could not load 3D model."; s.classList.add("error"); }
             setProgress(0);
+            setStep("error", msg || "Could not load 3D model.");
         }
         function showData(extra) {
             var d = el.querySelector(".model-viewer-data");
@@ -183,6 +232,7 @@
 
         setProgress(null);
         setStatus("Loading 3D libraries\u2026");
+        setStep("loading", "Loading 3D libraries");
 
         loadThree(function () {
             var wrap = el.querySelector(".model-viewer-canvas") || el;
@@ -226,6 +276,9 @@
                 camera.position.set(center.x + d * 0.9, center.y + d * 0.6, center.z + d);
                 controls.target.copy(center);
                 controls.update();
+                camera.near = d * 0.05;
+                camera.far = d * 10;
+                camera.updateProjectionMatrix();
             }
             function showCanvas() {
                 wrap.innerHTML = "";
@@ -240,6 +293,7 @@
             fetchProgress(url, function (p) { setProgress(p); }).then(function (buf) {
                 fileSize = buf.byteLength;
                 showData();
+                setStep("loading", "Downloaded model " + formatBytes(fileSize));
                 var data = new Uint8Array(buf);
                 if (isStep) {
                     setStatus("Downloading STEP parser\u2026");
@@ -247,32 +301,38 @@
                     fetchProgress(OCCT_WASM_ABS, function () {}).then(function (wasmBuf) {
                         setStatus("Parsing STEP\u2026");
                         setProgress(null);
+                        setStep("parsing", "STEP parser ready, parsing");
                         var t0 = Date.now();
-                        var parseTimer = setInterval(function () { setStatus("Parsing STEP\u2026 (" + Math.round((Date.now() - t0) / 1000) + "s)"); }, 1000);
+                        var parseTimer = setInterval(function () {
+                            var el2 = Date.now() - t0;
+                            setStatus("Parsing STEP\u2026 (" + Math.round(el2 / 1000) + "s)");
+                            setStep("parsing", "Parsing STEP " + Math.round(el2 / 1000) + "s");
+                            if (el2 > 240000 && !settled) { worker.terminate(); URL.revokeObjectURL(wurl); clearInterval(parseTimer); onError("STEP parse timed out."); }
+                        }, 1000);
                         var blob = new Blob([WORKER_SRC], { type: "application/javascript" });
                         var wurl = URL.createObjectURL(blob);
-                        var worker = new Worker(wurl);
+                        var worker = new Worker(wurl, { type: "module" });
                         var settled = false;
                         worker.onmessage = function (e) {
-                            if (e.data.type === "ready") {
+                            if (e.data.type === "done") {
-                                worker.postMessage({ type: "parse", data: data, params: STEP_PARAMS }, [data.buffer]);
-                            } else if (e.data.type === "done") {
                                 settled = true; worker.terminate(); URL.revokeObjectURL(wurl); clearInterval(parseTimer);
-                                if (!e.data.success) { onError("Could not parse STEP file."); return; }
+                                try {
-                                var tris = 0;
-                                (e.data.meshes || []).forEach(function (m) {
                                     var geo = new THREE.BufferGeometry();
-                                    geo.setAttribute("position", new THREE.Float32BufferAttribute(m.position, 3));
+                                    geo.setAttribute("position", new THREE.Float32BufferAttribute(e.data.positions, 3));
-                                    if (m.index) geo.setIndex(m.index);
+                                    if (e.data.indices) geo.setIndex(new THREE.BufferAttribute(e.data.indices, 1));
-                                    geo.computeVertexNormals();
+                                    var geoStats = "posV=" + geo.attributes.position.count + " idx=" + (geo.index ? geo.index.count : 0);
-                                    var color = m.color && m.color.length === 3 ? new THREE.Color(m.color[0], m.color[1], m.color[2]) : null;
+                                    fixWinding(geo);
-                                    var mat = new THREE.MeshStandardMaterial({ color: color || 0xb8bb26, metalness: 0.2, roughness: 0.6, side: THREE.DoubleSide, flatShading: true });
+                                    var mat = new THREE.MeshStandardMaterial({ color: 0xb8bb26, metalness: 0.2, roughness: 0.6, side: THREE.DoubleSide, flatShading: false });
-                                    group.add(new THREE.Mesh(geo, mat));
+                                    chunkGeometry(geo, group, mat);
-                                    tris += geo.index ? geo.index.count / 3 : geo.attributes.position.count / 3;
+                                    var tris = (e.data.indices && e.data.indices.length) ? e.data.indices.length / 3 : e.data.positions.length / 9;
-                                });
                                     fit();
                                     showCanvas();
                                     showData(formatCount(tris) + " triangles");
+                                    var capGL = renderer.capabilities ? (renderer.capabilities.isWebGL2 ? "WebGL2" : "WebGL1") : "?";
+                                    setStep("done", "Rendered " + formatCount(tris) + " tris; meshes=" + group.children.length + " gl=" + capGL + " " + geoStats);
+                                } catch (err) {
+                                    onError("build: " + (err && err.message || err));
+                                }
                             } else if (e.data.type === "error") {
                                 settled = true; worker.terminate(); URL.revokeObjectURL(wurl); clearInterval(parseTimer);
                                 onError(e.data.message || "Could not parse STEP file.");
@@ -281,7 +341,7 @@
                         worker.onerror = function (e) {
                             if (!settled) { settled = true; worker.terminate(); URL.revokeObjectURL(wurl); clearInterval(parseTimer); onError("STEP worker error: " + (e && e.message || "unknown")); }
                         };
-                        worker.postMessage({ type: "loadLib", libUrl: OCCT_JS_ABS, wasm: new Uint8Array(wasmBuf) }, [wasmBuf]);
+                        worker.postMessage({ type: "parse", data: data, params: STEP_PARAMS, wasm: new Uint8Array(wasmBuf) }, [data.buffer, wasmBuf]);
                     }).catch(function () { onError("Could not download STEP parser."); });
                 } else {
                     var geo = new THREE.STLLoader().parse(data.buffer);

theme/blog_share_theme.css

@@ -918,6 +918,21 @@ html.theme-light #content code {
     height: 100%;
 }
 
+.model-viewer.model-loading { background: #282828; }
+.model-viewer.model-parsing { background: #504945; }
+.model-viewer.model-done { background: #1d2021; }
+.model-viewer.model-error { background: #3c3836; }
+
+.model-viewer-debug {
+    font-family: "JetBrains Mono", Consolas, monospace;
+    font-size: 0.72em;
+    color: #928374;
+    text-align: center;
+    padding: 4px 12px;
+    background: #1d2021;
+    border-top: 1px solid var(--background-highlight);
+}
+
 /* ---------- Bildunterschriften (Gruvbox) ---------- */
 #content figcaption {
     font-size: 0.85em;