# Embedding a 3D model (STEP / STL) in a note

The share can render `.step` / `.stp` / `.stl` models interactively (three.js + occt-import-js,
hosted locally). There are two ways to embed a model, depending on how you store the file.

## Option A – Model as its own note (file note)

1. Create (or upload) a **file note** and make sure its **title ends in `.step`, `.stp` or `.stl`**,
   e.g. `bracket.step` or `rear_housing.stp`.
2. Put it under a category in the blog and set `publish=true`.
3. The note's share page then shows the interactive **3D viewer** automatically:
   drag to rotate, scroll to zoom; below the model there is a caption with the file name.

## Option B – Model embedded inline in a text note (attachment)

1. Upload the STEP/STL file as an **attachment** of the note:
   drag & drop it onto the note, or use the attachment dialog (paperclip icon).
2. **Rename the attachment** so its title ends in `.step`, `.stp` or `.stl`
   (the viewer detects a model by the file name). Example: `flange.step`.
3. **Insert the attachment link** into the note body:
   right-click the attachment → “Insert link”, or drag the attachment into the text.
   (Trilium creates a link showing the file name.)
4. On the share, that link is automatically replaced by the embedded 3D viewer.

> 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). The first STEP view downloads the
> ~7.6 MB WASM once and then caches it in the browser.

## Requirements

- The `3d model viewer` script must be wired: `~shareHtml → 3d model viewer`
  (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__`,
  `__OCCT_WASM_ID__` (see the README installation for the note titles).