2D Primitives

All 2D primitives can be transformed with 3D transformations and are typically used as input for extrusion operations.

square

Create a rectangle in the first quadrant. When center is true, it is centered at the origin.

Syntax:

Python

square(dim=1, center=False)

Parameters:

Parameter	Type	Default	Description
`dim`	number or `[x, y]`	`1`	A single number creates a square; a list creates a rectangle
`center`	bool	`False`	Center on the origin

Examples:

Python

from openscad import *

square(10).show()

square([20, 10]).show()

square([20, 10], center=True).show()

OpenSCAD reference: square

circle

Create a circle at the origin.

Syntax:

Python

circle(r=1)
circle(d=2)
circle(r=1, angle=360)

Parameters:

Parameter	Type	Default	Description
`r`	float	`1`	Radius
`d`	float	—	Diameter (alternative to `r`; cannot specify both)
`angle`	float	`360`	Arc angle in degrees (PythonSCAD extension)
`fn`	int	—	Number of segments (also sets polygon sides, e.g. `fn=6` for hexagon)
`fa`	float	—	Minimum angle per segment
`fs`	float	—	Minimum segment size

PythonSCAD extensions:

The angle parameter creates a pie/sector shape:

Python

from openscad import *

circle(r=5, angle=70).show()

Examples:

Python

from openscad import *

circle(10).show()

circle(d=20).show()

# Hexagon
circle(r=5, fn=6).show()

# High-resolution circle
circle(r=10, fn=100).show()

OpenSCAD reference: circle

polygon

Create a 2D polygon from a list of points.

Syntax:

Python

polygon(points, paths=None, convexity=2)

Parameters:

Parameter	Type	Default	Description
`points`	list of `[x, y]`	—	Vertex coordinates
`paths`	list of index lists	`None`	Optional paths defining which points form each outline/hole. If omitted, points are connected in order
`convexity`	int	`2`	Maximum number of front/back faces a ray can intersect

Examples:

Python

from openscad import *

polygon([[0, 0], [10, 0], [5, 10]]).show()

# Polygon with a hole
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]]
).show()

OpenSCAD reference: polygon

polyline

Create an open polyline from a list of points. Unlike polygon, a polyline is not necessarily closed and has no area. It is useful for defining cut lines in laser cutting workflows.

Syntax:

Python

polyline(points)

Parameters:

Parameter	Type	Default	Description
`points`	list of `[x, y]`	—	Vertex coordinates connected by line segments

Polylines can carry color but have no area and are ignored in CSG operations.

Examples:

Python

from openscad import *

for i in range(10):
    polyline([[0, i], [20, i]]).show()

spline

Create a smooth 2D curve that passes through the given control points. Similar to polygon but produces a smooth, rounded shape.

Syntax:

Python

spline(points, fn=0, fa=0, fs=0)

Parameters:

Parameter	Type	Default	Description
`points`	list of `[x, y]`	—	Control points the spline passes through
`fn`	float	`0`	Number of interpolation segments
`fa`	float	`0`	Minimum angle
`fs`	float	`0`	Minimum segment size

Examples:

Python

from openscad import *

pts = [[0, 6], [10, -5], [20, 10], [0, 19]]
s = spline(pts, fn=20).linear_extrude(height=1)
s.show()

text

Create 2D text geometry.

Syntax:

Python

text(t, size=10, font="", spacing=1, direction="ltr",
     language="en", script="latin", halign="left", valign="baseline")

Parameters:

Parameter	Type	Default	Description
`t`	string	—	The text string to render
`size`	float	`10`	Font size
`font`	string	`""`	Font name (system font or path)
`spacing`	float	`1`	Character spacing multiplier
`direction`	string	`"ltr"`	Text direction: `"ltr"`, `"rtl"`, `"ttb"`, `"btt"`
`language`	string	`"en"`	Language for text shaping
`script`	string	`"latin"`	Script for text shaping
`halign`	string	`"left"`	Horizontal alignment: `"left"`, `"center"`, `"right"`
`valign`	string	`"baseline"`	Vertical alignment: `"top"`, `"center"`, `"baseline"`, `"bottom"`
`fn`	int	—	Number of segments for curves

Examples:

Python

from openscad import *

text("Hello PythonSCAD", size=10).linear_extrude(height=2).show()

text("Centered", size=15, halign="center", valign="center").show()

OpenSCAD reference: text

textmetrics

Get the bounding box metrics of a text string without creating geometry. Returns a dictionary with dimension information.

Syntax:

Python

textmetrics(t, size=10, font="", spacing=1, direction="ltr",
            language="en", script="latin", halign="left", valign="baseline")

Parameters:

Same parameters as text.

Returns: A dictionary containing text metrics (bounding box dimensions, advance width, etc.).

Examples:

Python

from openscad import *

m = textmetrics("Hello", size=10)
print(m)