OpenSCAD Workbench

Preview OpenSCAD models inside VS Code: color, customizer sliders, cross-sections and 2D slice measurement. The model renders in an editor panel next to the code, not in a separate application.

Requirements

OpenSCAD must be installed. The extension needs the Manifold backend and colored 3MF export, so use a 2025 or newer development snapshot; the 2021.01 stable release is too old, and the preview says so rather than failing on the first render.

Take it from the Development Snapshots section of openscad.org/downloads.html. The release offered at the top of that page, and the plain openscad Homebrew cask, are both 2021.01.

On macOS, brew install --cask openscad@snapshot is the one-line route. The .dmg works too: drag OpenSCAD.app into /Applications and the extension looks inside the bundle, so there is nothing further to configure.

The extension finds it by, in order:

1. the scadPreview.openscadPath setting, if set;
2. the newest OpenSCAD*.AppImage in the file's folder or any folder above it;
3. on macOS, the newest OpenSCAD*.app in /Applications or ~/Applications;
4. openscad on PATH.

On Windows there is no standard location to search, so set scadPreview.openscadPath to your openscad.exe.

Use

Open a .scad file and click the preview icon in the editor title bar, or run OpenSCAD Workbench: Open Preview from the command palette. The model re-renders when you save the file or any file it includes or uses.

• Parameters — sliders, dropdowns, checkboxes and text fields built from the file's Customizer comments, with saveable presets. Dragging a slider renders at reduced $fn for speed and does one full render when you let go.
• Section — cut the model on any axis and see a solid cut face.
• Measure — on a cut, snap to the outline to measure distances, wall thickness, angles and bounding boxes. echo("measure", ...) in the file draws its own measurements in a second color. Measurements you add by hand are kept in a .scad-preview/ folder beside the file, which is worth adding to .gitignore.
• Debug modifiers — # parts are drawn see-through in a highlight color and % parts faintly, from a second pass that runs after each render.
• Export — write STL or 3MF with the parameter values currently in the panel.

Everything else — colors, panel sides and widths, the navigation cube, orthographic view, facet edges — is under scadPreview.* in Settings.

Performance notes

Two settings exist because OpenSCAD process startup dominates small renders:

• scadPreview.unpackAppImage (on by default) unpacks the AppImage once into the extension's storage, about 300 MB, and runs the unpacked copy. Starting an AppImage costs about 0.3 s per render; the unpacked copy starts in about 0.05 s. It is redone when the AppImage changes.
• scadPreview.draftFn sets the $fn used for the quick renders while a slider is moving.

Develop

npm install
npm run build      # bundle extension + webview into dist/
npm test           # unit tests
npm run typecheck
npm run package    # build a .vsix

Press F5 to launch a development host. By default it opens whatever folder you point the launch configuration at; open a .scad file there and click the preview button.

docs/openscad-cli-findings.md records what the OpenSCAD command line does and does not support, which is where most of the design constraints come from.

License

GPL-3.0-or-later. See LICENSE, and THIRD-PARTY-NOTICES.md for the bundled MIT libraries.