All 2D primitives can be transformed with 3D transformations. Usually used as part of a 3D extrusion. Although infinitely thin, they are rendered with a 1 thickness.
Creates a square or rectangle in the first quadrant. When center is true the square is centered on the origin. Argument names are optional if given in the order shown here.
square(size = [x, y], center = true/false); square(size = x , center = true/false);
default values: square(); yields: square(size = [1, 1], center = false);
equivalent scripts for this example square(size = 10); square(10); square([10,10]); . square(10,false); square([10,10],false); square([10,10],center=false); square(size = [10, 10], center = false); square(center = false,size = [10, 10] );
equivalent scripts for this example square([20,10],true); a=[20,10];square(a,true);
Creates a circle at the origin. All parameters, except r, must be named.
circle(r=radius | d=diameter);
scale([1/100, 1/100, 1/100]) circle(200); // create a high resolution circle with a radius of 2. circle(2, $fn=50); // Another way.
defaults: circle(); yields: circle($fn = 0, $fa = 12, $fs = 2, r = 1);
equivalent scripts for this example circle(10); circle(r=10); circle(d=20); circle(d=2+9*2);
An ellipse can be created from a circle by using either scale() or resize() to make the x and y dimensions unequal. See OpenSCAD User Manual/Transformations
equivalent scripts for this example resize([30,10])circle(d=20); scale([1.5,.5])circle(d=20);
A regular polygon of 3 or more sides can be created by using circle() with $fn set to the number of sides. The following two pieces of code are equivalent.
circle(r=1, $fn=4);
module regular_polygon(order = 4, r=1){ angles=[ for (i = [0:order-1]) i*(360/order) ]; coords=[ for (th=angles) [r*cos(th), r*sin(th)] ]; polygon(coords); } regular_polygon();
These result in the following shapes, where the polygon is inscribed within the circle with all sides (and angles) equal. One corner points to the positive x direction. For irregular shapes see the polygon primitive below.
script for these examples translate([-42, 0]){circle(20,$fn=3);%circle(20,$fn=90);} translate([ 0, 0]) circle(20,$fn=4); translate([ 42, 0]) circle(20,$fn=5); translate([-42,-42]) circle(20,$fn=6); translate([ 0,-42]) circle(20,$fn=8); translate([ 42,-42]) circle(20,$fn=12);
color("black"){ translate([-42, 0,1])text("3",7,,center); translate([ 0, 0,1])text("4",7,,center); translate([ 42, 0,1])text("5",7,,center); translate([-42,-42,1])text("6",7,,center); translate([ 0,-42,1])text("8",7,,center); translate([ 42,-42,1])text("12",7,,center); }
Creates a multiple sided shape from a list of x,y coordinates. A polygon is the most powerful 2D object. It can create anything that circle and squares can, as well as much more. This includes irregular shapes with both concave and convex edges. In addition it can place holes within that shape.
polygon(points = [ [x, y], ... ], paths = [ [p1, p2, p3..], ...], convexity = N);
defaults: polygon(); yields: polygon(points = undef, paths = undef, convexity = 1);
equivalent scripts for this example polygon(points=[[0,0],[100,0],[130,50],[30,50]]); polygon([[0,0],[100,0],[130,50],[30,50]], paths=[[0,1,2,3]]); polygon([[0,0],[100,0],[130,50],[30,50]],[[3,2,1,0]]); polygon([[0,0],[100,0],[130,50],[30,50]],[[1,0,3,2]]); a=[[0,0],[100,0],[130,50],[30,50]]; b=[[3,0,1,2]]; polygon(a); polygon(a,b); polygon(a,[[2,3,0,1,2]]);
equivalent scripts for this example polygon(points=[[0,0],[100,0],[0,100],[10,10],[80,10],[10,80]], paths=[[0,1,2],[3,4,5]],convexity=10); triangle_points =[[0,0],[100,0],[0,100],[10,10],[80,10],[10,80]]; triangle_paths =[[0,1,2],[3,4,5]]; polygon(triangle_points,triangle_paths,10);
The 1st path vector, [0,1,2], selects the points, [0,0],[100,0],[0,100], for the primary shape. The 2nd path vector, [3,4,5], selects the points, [10,10],[80,10],[10,80], for the secondary shape. The secondary shape is subtracted from the primary ( think difference() ). Since the secondary is wholly within the primary, it leaves a shape with a hole.
[Note: Requires version 2015.03] (for use of concat()
)
//example polygon with multiple holes a0 = [[0,0],[100,0],[130,50],[30,50]]; // main b0 = [1,0,3,2]; a1 = [[20,20],[40,20],[30,30]]; // hole 1 b1 = [4,5,6]; a2 = [[50,20],[60,20],[40,30]]; // hole 2 b2 = [7,8,9]; a3 = [[65,10],[80,10],[80,40],[65,40]]; // hole 3 b3 = [10,11,12,13]; a4 = [[98,10],[115,40],[85,40],[85,10]]; // hole 4 b4 = [14,15,16,17]; a = concat (a0,a1,a2,a3,a4); b = [b0,b1,b2,b3,b4]; polygon(a,b); //alternate polygon(a,[b0,b1,b2,b3,b4]);
The convexity parameter specifies the maximum number of front sides (back sides) a ray intersecting the object might penetrate. This parameter is needed only for correct display of the object in OpenCSG preview mode and has no effect on the polyhedron rendering.
This image shows a 2D shape with a convexity of 4, as the ray indicated in red crosses the 2D shape a maximum of 4 times. The convexity of a 3D shape would be determined in a similar way. Setting it to 10 should work fine for most cases.
[Deprecated: import_dxf() will be removed in future releases. Use import() instead.]
Read a DXF file and create a 2D shape.
Example
linear_extrude(height = 5, center = true, convexity = 10) import_dxf(file = "example009.dxf", layer = "plate");
The text
module creates text as a 2D geometric object,
using fonts installed on the local system or provided as separate font file.
[Note: Requires version 2015.03]
Parameters
Example
text("OpenSCAD");
To allow specification of particular Unicode characters, you can specify them in a string with the following escape codes;
The null character (NUL) is mapped to the space character (SP).
assert(version() == [2019, 5, 0]); assert(ord(" ") == 32); assert(ord("\x00") == 32); assert(ord("\u0000") == 32); assert(ord("\U000000") == 32);
Example
t="\u20AC10 \u263A"; // 10 euro and a smilie
Fonts are specified by their logical font name; in addition a style parameter can be added to select a specific font style like "bold" or "italic", such as:
font="Liberation Sans:style=Bold Italic"
The font list dialog (available under Help > Font List) shows the font name and the font style for each available font. For reference, the dialog also displays the location of the font file. You can drag a font in the font list, into the editor window to use in the text() statement.
OpenSCAD includes the fonts Liberation Mono, Liberation Sans, and Liberation Serif. Hence, as fonts in general differ by platform type, use of these included fonts is likely to be portable across platforms.
For common/casual text usage, the specification of one of these fonts is recommended for this reason. Liberation Sans is the default font to encourage this.
In addition to the installed fonts, it's possible to add project specific font files. Supported font file formats are TrueType Fonts (*.ttf) and OpenType Fonts (*.otf). The files need to be registered with use<>.
use <ttf/paratype-serif/PTF55F.ttf>
After the registration, the font is listed in the font list dialog, so in case logical name of a font is unknown, it can be looked up as it was registered.
OpenSCAD uses fontconfig to find and manage fonts, so it's possible to list the system configured fonts on command line using the fontconfig tools in a format similar to the GUI dialog.
$ fc-list -f "%-60{{%{family[0]}%{:style[0]=}}}%{file}\n" | sort ... Liberation Mono:style=Bold Italic /usr/share/fonts/truetype/liberation2/LiberationMono-BoldItalic.ttf Liberation Mono:style=Bold /usr/share/fonts/truetype/liberation2/LiberationMono-Bold.ttf Liberation Mono:style=Italic /usr/share/fonts/truetype/liberation2/LiberationMono-Italic.ttf Liberation Mono:style=Regular /usr/share/fonts/truetype/liberation2/LiberationMono-Regular.ttf ...
Example
square(10); translate([15, 15]) { text("OpenSCAD", font = "Liberation Sans"); } translate([15, 0]) { text("OpenSCAD", font = "Liberation Sans:style=Bold Italic"); }
text = "Align"; font = "Liberation Sans"; valign = [ [ 0, "top"], [ 40, "center"], [ 75, "baseline"], [110, "bottom"] ]; for (a = valign) { translate([10, 120 - a[0], 0]) { color("red") cube([135, 1, 0.1]); color("blue") cube([1, 20, 0.1]); linear_extrude(height = 0.5) { text(text = str(text,"_",a[1]), font = font, size = 20, valign = a[1]); } } }
text = "Align"; font = "Liberation Sans"; halign = [ [10, "left"], [50, "center"], [90, "right"] ]; for (a = halign) { translate([140, a[0], 0]) { color("red") cube([115, 2,0.1]); color("blue") cube([2, 20,0.1]); linear_extrude(height = 0.5) { text(text = str(text,"_",a[1]), font = font, size = 20, halign = a[1]); } } }
Text can be changed from a 2 dimensional object into a 3D object by using the linear_extrude function.
//3d Text Example linear_extrude(4) text("Text");
Using the projection()
function, you can create 2d drawings from 3d models, and export them to the dxf format. It works by projecting a 3D model to the (x,y) plane, with z at 0. If cut=true
, only points with z=0 are considered (effectively cutting the object), with cut=false
(the default), points above and below the plane are considered as well (creating a proper projection).
Example: Consider example002.scad, that comes with OpenSCAD.
Then you can do a 'cut' projection, which gives you the 'slice' of the x-y plane with z=0.
projection(cut = true) example002();
You can also do an 'ordinary' projection, which gives a sort of 'shadow' of the object onto the xy plane.
projection(cut = false) example002();
Another Example
You can also use projection to get a 'side view' of an object. Let's take example002, and move it up, out of the X-Y plane, and rotate it:
translate([0,0,25]) rotate([90,0,0]) example002();
Now we can get a side view with projection()
projection() translate([0,0,25]) rotate([90,0,0]) example002();
Links:
Extrusion is the process of creating an object with a fixed cross-sectional profile. OpenSCAD provides two commands to create 3D solids from a 2D shape: linear_extrude() and rotate_extrude(). Linear extrusion is similar to pushing Playdoh through a press with a die of a specific shape.
Rotational extrusion is similar to the process of turning or "throwing" a bowl on the Potter's wheel.
Both extrusion methods work on a (possibly disjointed) 2D shape which exists on the X-Y plane. While transformations that operates on both 2D shapes and 3D solids can move a shape off the X-Y plane, when the extrusion is performed the end result is not very intuitive. What actually happens is that any information in the third coordinate (the Z coordinate) is ignored for any 2D shape, this process amounts to an implicit projection() performed on any 2D shape before the extrusion is executed. It is recommended to perform extrusion on shapes that remains strictly on the X-Y plane.
Linear Extrusion is a operation that takes a 2D object as input and generates a 3D object as a result.
In OpenSCAD Extrusion is always performed on the projection (shadow) of the 2d object xy plane and along the Z axis; so if you rotate or apply other transformations to the 2d object before extrusion, its shadow shape is what is extruded.
Although the extrusion is linear along the Z axis, a twist parameter is available that causes the object to be rotated around the Z axis as it is extruding upward. This can be used to rotate the object at it's center, as if it is a spiral pillar, or produce a helical extrusion around the Z axis, like a pig's tail.
A scale parameter is also included so that the object can be expanded or contracted over the extent of the extrusion, allowing extrusions to be flared inward or outward.
linear_extrude(height = 5, center = true, convexity = 10, twist = -fanrot, slices = 20, scale = 1.0, $fn = 16) {...}
You must use parameter names due to a backward compatibility issue.
height
must be positive.
$fn
is optional and specifies the resolution of the linear_extrude (higher number brings more "smoothness", but more computation time is needed).
If the extrusion fails for a non-trivial 2D shape, try setting the convexity parameter (the default is not 10, but 10 is a "good" value to try). See explanation further down.
Twist is the number of degrees of through which the shape is extruded. Setting the parameter twist = 360 extrudes through one revolution. The twist direction follows the left hand rule.
0° of Twist
linear_extrude(height = 10, center = true, convexity = 10, twist = 0) translate([2, 0, 0]) circle(r = 1);
-100° of Twist
linear_extrude(height = 10, center = true, convexity = 10, twist = -100) translate([2, 0, 0]) circle(r = 1);
100° of Twist
linear_extrude(height = 10, center = true, convexity = 10, twist = 100) translate([2, 0, 0]) circle(r = 1);
-500° of Twist
linear_extrude(height = 10, center = true, convexity = 10, twist = -500) translate([2, 0, 0]) circle(r = 1);
It is similar to the parameter center of cylinders. If center
is false the linear extrusion Z range is from 0 to height; if it is true, the range is from -height/2 to height/2.
center = true
linear_extrude(height = 10, center = true, convexity = 10, twist = -500) translate([2, 0, 0]) circle(r = 1);
center = false
linear_extrude(height = 10, center = false, convexity = 10, twist = -500) translate([2, 0, 0]) circle(r = 1);
The slices parameter defines the number of intermediate points along the Z axis of the extrusion. Its default increases with the value of twist. Explicitly setting slices may improve the output refinement.
linear_extrude(height = 10, center = false, convexity = 10, twist = 360, slices = 100) translate([2, 0, 0]) circle(r = 1);
The special variables $fn, $fs and $fa can also be used to improve the output. If slices is not defined, its value is taken from the defined $fn value.
linear_extrude(height = 10, center = false, convexity = 10, twist = 360, $fn = 100) translate([2, 0, 0]) circle(r = 1);
Scales the 2D shape by this value over the height of the extrusion. Scale can be a scalar or a vector:
linear_extrude(height = 10, center = true, convexity = 10, scale=3) translate([2, 0, 0]) circle(r = 1);
linear_extrude(height = 10, center = true, convexity = 10, scale=[1,5], $fn=100) translate([2, 0, 0]) circle(r = 1);
Note that if scale is a vector, the resulting side walls may be nonplanar. Use twist=0
and the slices
parameter to avoid asymmetry.
linear_extrude(height=10, scale=[1,0.1], slices=20, twist=0) polygon(points=[[0,0],[20,10],[20,-10]]);
Rotational extrusion spins a 2D shape around the Z-axis to form a solid which has rotational symmetry. One way to think of this operation is to imagine a Potter's wheel placed on the X-Y plane with its axis of rotation pointing up towards +Z. Then place the to-be-made object on this virtual Potter's wheel (possibly extending down below the X-Y plane towards -Z). The to-be-made object is the cross-section of the object on the X-Y plane (keeping only the right half, X >= 0). That is the 2D shape that will be fed to rotate_extrude() as the child in order to generate this solid. Note that the object started on the X-Y plane but is tilted up (rotated +90 degrees about the X-axis) to extrude.
Since a 2D shape is rendered by OpenSCAD on the X-Y plane, an alternative way to think of this operation is as follows: spins a 2D shape around the Y-axis to form a solid. The resultant solid is placed so that its axis of rotation lies along the Z-axis.
Just like the linear_extrude, the extrusion is always performed on the projection of the 2D polygon to the XY plane. Transformations like rotate, translate, etc. applied to the 2D polygon before extrusion modify the projection of the 2D polygon to the XY plane and therefore also modify the appearance of the final 3D object.
Don't get confused, as OpenSCAD renders 2D polygons with a certain height in the Z direction, so the 2D object (with its height) appears to have a bigger projection to the XY plane. But for the projection to the XY plane and also for the later extrusion only the base polygon without height is used.
It can not be used to produce a helix or screw threads.
The 2D shape must lie completely on either the right (recommended) or the left side of the Y-axis. More precisely speaking, every vertex of the shape must have either x >= 0 or x <= 0. If the shape spans the X axis a warning appears in the console windows and the rotate_extrude() is ignored. If the 2D shape touches the Y axis, i.e. at x=0, it must be a line that touches, not a point, as a point results in a zero thickness 3D object, which is invalid and results in a CGAL error. For OpenSCAD versions prior to 2016.xxxx, if the shape is in the negative axis the resulting faces are oriented inside-out, which may cause undesired effects.
rotate_extrude(angle = 360, convexity = 2) {...}
You must use parameter names due to a backward compatibility issue.
A simple torus can be constructed using a rotational extrude.
rotate_extrude(convexity = 10) translate([2, 0, 0]) circle(r = 1);
Increasing the number of fragments composing the 2D shape improves the quality of the mesh, but takes longer to render.
rotate_extrude(convexity = 10) translate([2, 0, 0]) circle(r = 1, $fn = 100);
The number of fragments used by the extrusion can also be increased.
rotate_extrude(convexity = 10, $fn = 100) translate([2, 0, 0]) circle(r = 1, $fn = 100);
Using the parameter angle (with OpenSCAD versions 2016.xx), a hook can be modeled .
translate([0,60,0]) rotate_extrude(angle=270, convexity=10) translate([40, 0]) circle(10); rotate_extrude(angle=90, convexity=10) translate([20, 0]) circle(10); translate([20,0,0]) rotate([90,0,0]) cylinder(r=10,h=80);
Extrusion can also be performed on polygons with points chosen by the user.
Here is a simple polygon and its 200 step rotational extrusion. (Note it has been rotated 90 degrees to show how the rotation appears; the rotate_extrude()
needs it flat).
rotate([90,0,0]) polygon( points=[[0,0],[2,1],[1,2],[1,3],[3,4],[0,5]] );
rotate_extrude($fn=200) polygon( points=[[0,0],[2,1],[1,2],[1,3],[3,4],[0,5]] );
For more information on polygons, please see: 2D Primitives: Polygon.
convexity | Integer. The convexity parameter specifies the maximum number of front sides (or back sides) a ray intersecting the object might penetrate.
This parameter is only needed for correctly displaying the object in OpenCSG preview mode and has no effect on the polyhedron rendering. |
This image shows a 2D shape with a convexity of 2, as the ray indicated in red crosses the 2D shape a maximum of 4 times (2 front sides and 2 back sides). The convexity of a 3D shape would be determined in a similar way. Setting it to 10 should work fine for most cases. Just setting high numbers in general may result in slower preview rendering.
height | The extrusion height |
center | If true, the solid is centered after extrusion |
twist | The extrusion twist in degrees |
slices | Similar to special variable $fn without being passed down to the child 2D shape. |
scale | Scales the 2D shape by this value over the height of the extrusion. |
With the import() and extrusion modules it is possible to convert 2D objects read from DXF files to 3D objects. See also 2D to 3D Extrusion.
Example of linear extrusion of a 2D object imported from a DXF file.
linear_extrude(height = fanwidth, center = true, convexity = 10) import (file = "example009.dxf", layer = "fan_top");
Example of rotational extrusion of a 2D object imported from a DXF file.
rotate_extrude(convexity = 10) import (file = "example009.dxf", layer = "fan_side", origin = fan_side_center);
Inkscape is an open source drawing program. Tutorials for transferring 2d DXF drawings from Inkscape to OpenSCAD are available here: