OpenSCAD 2D primitives & extrusion

2D primitives live in the XY plane and become 3D when you extrude them with linear_extrude (push them up along Z) or rotate_extrude (sweep them around the Z axis to make rotationally-symmetric parts). Most non-boxy real-world parts are cheapest to build this way.

circle

circle(r);
circle(d=diameter);

Like sphere, takes r OR d and honors $fn/$fa/$fs. Use $fn=6 for a hexagon, $fn=3 for an equilateral triangle.

square

square(size, center=false);
square([w, h], center=false);

A 2D rectangle. size can be a single number (square) or a 2-vector [width, height].

polygon

The escape hatch for any 2D shape you can describe with a list of points.

polygon(points = [[0,0], [20,0], [20,10], [10,15], [0,10]]);

// With holes (multiple paths):
polygon(
  points = [[0,0],[20,0],[20,20],[0,20],
            [5,5],[15,5],[15,15],[5,15]],
  paths  = [[0,1,2,3], [4,5,6,7]]   // outer + inner hole
);

text

Generates 2D text using a system or imported font. Becomes 3D when you linear_extrude it.

text("PrintPal", size=10, font="Liberation Sans:style=Bold",
     halign="center", valign="center");

linear_extrude(height=2)
  text("v1.2", size=5);

Parameters: size, font, halign, valign, direction, spacing, language, script.

import (2D)

import("logo.svg");
import("profile.dxf");

SVG support is the modern path; many people use SVG so they can author shapes in Inkscape or Figma and extrude them in OpenSCAD.

linear_extrude

Push a 2D shape straight up along Z. The flagship 2D→3D operator.

linear_extrude(height, center=false, convexity=10,
               twist=0, slices=20, scale=1) { ... }

Examples

linear_extrude(height=10) circle(d=20, $fn=64);

// Twisted vase profile
linear_extrude(height=60, twist=180, slices=60, scale=1.4, $fn=64)
  polygon([[0,0], [20,0], [15,8], [25,15], [0,18]]);

// 3D nameplate
linear_extrude(height=3)
  text("Hello", size=15, halign="center", valign="center");

rotate_extrude

Sweep a 2D shape around the Z axis. The 2D profile must sit entirely on the +X side of the Y axis (no negative X values). Use it for bottles, vases, wheels, pulleys, knobs — anything rotationally symmetric.

rotate_extrude(angle=360, convexity=10) { ... }

Vase

rotate_extrude($fn=120)
  polygon([
    [0,0], [22,0], [18,15],
    [26,40], [14,55], [0,55]
  ]);

Torus (offset circle, swept)

rotate_extrude($fn=128)
  translate([20, 0, 0])
    circle(r=5, $fn=48);

projection

Convert a 3D shape back into 2D — useful for generating DXF/SVG drawings from your model.

projection(cut=false) cube([40,20,10]);   // silhouette
projection(cut=true)
  translate([0,0,-5]) cylinder(h=10, d=20);  // cross-section at Z=0

offset

Grow or shrink a 2D shape. Round corners with r, chamfer with delta + chamfer=true.

offset(r=3) square([40, 20]);            // rounded rectangle
offset(delta=-1) polygon([[0,0],[10,0],[5,10]]);  // shrink by 1 mm
offset(delta=2, chamfer=true) square([10,10]);  // chamfered