Extrude

extrude() pulls a sketch upward (along the plane's normal) into a solid. It's the most common way to turn a 2D profile into 3D geometry.

sketch("xy", () => {
    rect(100, 60).center()
})

const e = extrude(30)          // extrude 30 units

No-argument extrude

extrude()                      // uses a default distance of 25

When called with no arguments, extrude() uses a default distance and supports interactive mouse input in the viewport — drag to set the distance visually.

Symmetric extrude

Extrude equally in both directions from the sketch plane:

extrude(40).symmetric()        // 20 up and 20 down

Draft angle

Add a taper to the extrusion:

extrude(30).draft(5)           // 5° draft angle — the shape narrows as it goes up

Region picking

When a sketch has multiple overlapping shapes that create several regions, use .pick() to select which region to extrude:

sketch("xy", () => {
    circle(60)
    circle(30)
})

extrude(20).pick([20, 0])      // extrude only the ring region near [20, 0]

Interactive mode

Call .pick() with no arguments to enter interactive mode. Click on regions in the viewport to select them.

Region picking can be fragile

When you pick a region by coordinates (or by clicking in interactive mode), those coordinates are saved in your code. If the sketch dimensions change later, the pick point may fall outside the resized regions, breaking the model.

This makes .pick() great for fast prototyping or models with fixed dimensions. For parametric models where dimensions are likely to change, prefer structuring your sketches so each sketch contains only the regions you need — avoiding the need for .pick() altogether.

Accessing geometry

const e = extrude(30)

e.endFaces()       // top face(s)
e.startFaces()     // bottom face(s)
e.sideFaces()      // side face(s)
e.endEdges()       // edges on the top
e.startEdges()     // edges on the bottom
e.sideEdges()      // edges on the sides
e.internalEdges()  // edges created inside (from fusion)
e.internalFaces()  // faces created inside (from fusion)

Fusion scope

By default, extrude fuses with any touching solid. Control this with:

extrude(30).new()              // create a separate solid, don't fuse
extrude(30).add()              // fuse with all touching solids (default)