Serpentine3D: An Open Source Nurbs Modeller and a Drafting Tool

Free and open source · Linux, Windows, macOS

Serpentine3D is a NURBS modeller and drafting tool for things that get built: exact curves and surfaces, drawing sheets a workshop can work from, and a command line that speaks Rhino. Free, with no account and no subscription.

Watch the trailer 0:56 Source on GitHub

Linux, Windows and macOS · version 0.12.0 · MIT licence

Watch the trailer 0:56

1view Single viewport. loft Lofted 4 curves into Surface 01.

Ask AI type a command (line, circle, extrude, loft, ...)

Osnap:OnEndPointMidCenQuadIntAppIntPerpNearGridOrtho

5 object(s) · 0 selected · layer: Vase · rendered · units: mm

Made in Serpentine3D · samples

Built for the trailer, and every one is a sample: download it, open it with File ▸ Open, and take it apart.

Surfaces here are NURBS, the same mathematics Rhino uses. A 300 mm radius is 300 mm at any zoom and on every drawing, and a pulled control point keeps the surface smooth.

Type a command and it walks you through the rest, with Rhino's names and aliases, object snaps, layers and a gumball for pushing faces and rounding edges by hand. Rhino .3dm files open with their layers, and STEP, DXF, STL, glTF and USD carry the model on to everything else.

Lay out A4 to A0 sheets with live detail views at real scales, 1:25 or 1:50. Hidden-line views, dimensions, leaders, hatching, scale bars and title blocks come from the model itself, and the sheet prints straight to PDF.

The assistant runs the same commands you do, then looks at the viewport to check its own work, and every step can be undone. Use Claude, a ChatGPT account or an OpenAI key, or keep everything on your machine with a local, open-weight model.

Zebra stripes and curvature colour show where surfaces meet smoothly. Draft analysis checks a mould will release, and printcheck finds open edges, thin walls and overhangs before the slicer does.

The same engine runs with no window at all. Script it in the built-in editor, batch a hundred variants from a terminal, run it in CI on a server with no display, or let any MCP client drive a live session.

box = doc.add(geo.make_box((0, 0, 0), 100, 100, 100), name="Crate") doc.run("filletedge", ["Crate", "", "5"]) doc.export(args[0] if args else "crate.step")

$ serp3d-batch make_part.py crate.step

Download

Every build is free, with no account and no subscription.

Your system

Linux

AppImage · x86_64 · 509 MB

One file. Make it executable and double-click it; no admin rights needed.

Unsigned for now: if Windows warns you, choose More info, then Run anyway.

Your system

macOS

Disk image · Apple Silicon · macOS 14+ · 268 MB

Unsigned for now: right-click the app and choose Open the first time.

Latest: version 0.12.0 Release notes →All releases →

No subscription, no licence server, no upgrade to Pro. One person builds Serpentine3D between other work; if it is useful to you, a small contribution keeps it moving.