Extrusions

Extrusion operations convert 2D shapes (or Python functions) into 3D solids.

linear_extrude

Extrude a 2D shape (or Python function) along the Z axis.

Syntax:

Python

linear_extrude(obj, height=1, convexity=1, origin=None, scale=None,
               center=False, slices=1, segments=0, twist=None)
obj.linear_extrude(height=1, ...)

Parameters:

Parameter	Type	Default	Description
`obj`	2D solid or function	—	Shape to extrude, or a Python function `f(h) -> [[x,y], ...]`
`height`	number or `[x,y,z]`	`1`	Extrusion height (number for Z-axis, vector for arbitrary direction)
`convexity`	int	`1`	Convexity for rendering
`origin`	`[x, y]`	`None`	Origin point for twist/scale operations
`scale`	`[x, y]`	`None`	Scale factor at the top of the extrusion
`center`	bool	`False`	Center vertically
`slices`	int	`1`	Number of intermediate slices
`segments`	int	`0`	Number of segments for twist
`twist`	number or function	`None`	Twist angle in degrees, or a Python function `f(h) -> angle`
`fn`, `fa`, `fs`		—	Curve discretization parameters

PythonSCAD extensions:

The obj parameter can be a Python function that receives a height value and returns a list of 2D points defining the cross-section at that height:

Python

from openscad import *
from math import *

def xsection(h):
    v = 5 + sin(h)
    return [[-v, -v], [v, -v], [v, v], [-v, v]]

linear_extrude(xsection, height=10, fn=20).show()

The twist parameter can also be a Python function:

Python

from openscad import *

square(5, center=True).linear_extrude(height=20, twist=90, slices=50).show()

Examples:

Python

from openscad import *

circle(5).linear_extrude(height=10).show()

circle(5).linear_extrude(height=10, twist=90, slices=50).show()

circle(5).linear_extrude(height=10, scale=[2, 0.5]).show()

OpenSCAD reference: linear_extrude

rotate_extrude

Extrude a 2D shape by rotating it around the Z axis.

Syntax:

Python

rotate_extrude(obj, convexity=1, scale=1.0, angle=360, twist=None,
               origin=None, offset=None, v=None, method=None)
obj.rotate_extrude(...)

Parameters:

Parameter	Type	Default	Description
`obj`	2D solid or function	—	Shape to extrude, or a Python function `f(angle) -> [[x,y], ...]`
`convexity`	int	`1`	Convexity for rendering
`scale`	float	`1.0`	Scale factor at the end of rotation
`angle`	float	`360`	Rotation angle in degrees
`twist`	number or function	`None`	Twist angle or function
`origin`	`[x, y]`	`None`	Origin for twist/scale
`offset`	`[x, y]`	`None`	Offset for the profile
`v`	`[x, y, z]`	`None`	Translation per revolution for helix (PythonSCAD extension)
`method`	string	`None`	Extrusion method
`fn`, `fa`, `fs`		—	Curve discretization parameters

PythonSCAD extensions:

The obj parameter can be a Python function that receives an angle and returns a 2D cross-section:

Python

from openscad import *
from math import *

def xsection(h):
    v = 2 * sin(4 * pi * h)
    return [[10+v, -v], [15-v, -v], [15-v, 5+v], [10+v, 5+v]]

rotate_extrude(xsection, fn=50).show()

The v parameter creates a helix by translating the profile along a vector per revolution:

Python

from openscad import *

circle(3).right(10).rotate_extrude(v=[0, 0, 20], angle=600).show()

Examples:

Python

from openscad import *

# Simple torus
circle(3).right(10).rotate_extrude().show()

# Partial rotation
square([2, 3]).right(5).rotate_extrude(angle=270).show()

OpenSCAD reference: rotate_extrude

path_extrude

Extrude a 2D shape along an arbitrary 3D path. A 4th value in each path vertex specifies the corner radius at that point.

Syntax:

Python

path_extrude(obj, path, xdir=None, convexity=1, origin=None,
             scale=None, twist=None, closed=False, fn=-1, fa=-1, fs=-1)
obj.path_extrude(path, ...)

Parameters:

Parameter	Type	Default	Description
`obj`	2D solid or function	—	Cross-section shape or Python function
`path`	list of `[x,y,z]` or `[x,y,z,r]`	—	3D path points; optional 4th element is corner radius
`xdir`	`[x, y, z]`	`[1, 0, 0]`	X-direction vector for profile orientation
`convexity`	int	`1`	Convexity for rendering
`origin`	`[x, y]`	`None`	Origin for the profile
`scale`	`[x, y]`	`None`	Scale factor at the end
`twist`	number or function	`None`	Twist angle or function
`closed`	bool	`False`	Close the path into a loop
`fn`, `fa`, `fs`	float	`-1`	Curve discretization

Examples:

Python

from openscad import *

# Extrude a square along a path with rounded corners
p = path_extrude(
    square(1),
    [[0,0,0], [0,0,10,3], [10,0,10,3], [10,10,10]]
)
p.show()

skin

Create a surface that smoothly connects multiple 2D profiles placed in 3D space. This is essentially morphing between shapes.

Syntax:

Python

skin(obj1, obj2, ..., convexity=1, align_angle=None, segments=None, interpolate=None)

Parameters:

Parameter	Type	Default	Description
`obj1, obj2, ...`	2D solids	—	Profiles to skin between (positioned in 3D space)
`convexity`	int	`1`	Convexity for rendering
`align_angle`	float	`None`	Angle to align profiles
`segments`	int	`None`	Number of interpolation segments
`interpolate`	float	`None`	Interpolation factor

Examples:

Python

from openscad import *

# Morph a square into a circle
a = square(4, center=True).roty(40)
b = circle(r=2, fn=20).rotx(40).up(10)
skin(a, b).show()