OpenJSCAD User Guide

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Welcome to User and Programming Guide. Overview

Just for sake of providing context, is built on OpenJsCad (Github), which itself was inspired by, and essentially provides a programmers approach to develop 3D models. In particular, this enhancement is tuned towards creating precise models for 3D printing.

OpenJSCAD is object-oriented, and for programmers coming from OpenSCAD may welcome

  • ability to use JavaScript programming concepts and libraries
  • support for OpenSCAD source-code (approximately 95% of all functions)
  • additional functions to ease the transition to OpenJSCAD
  • ability to create and manipulate 3D shapes, as well as 2D shapes

Read on to find about more about OpenJSCAD.

There is also a Quick Reference.

OpenJSCAD User Guide[edit]

Web Browser & Command-Line Interface aka "Dual Use"[edit]

Web Browser (Online, Local & Offline)[edit] contains the editor (Graphical User Interface) for you:


where you can

  • edit online using the built-in editor, or
  • edit off-line via your favorite editor

Just drag & drop file(s) or folder into the area indicated in the browser.


In order to use your favorite editor, make sure Auto Reload is selected.


Note: Each browser (Firefox, Chrome, IE, etc) supports different functionality. Try another browser if your not satisfied with the performance of your current browser.

Local Installation (Offline)[edit]


* install NodeJS (e.g. ``apt-get install nodejs``)

Note: Be aware that NodeJS >= 0.8.1 is required. (Ubuntu 12.04 installs NodeJS 0.6.1).

Note: Check how the actual NodeJS executable is named, either `/usr/local/bin/node` (default) or `/usr/bin/nodejs` and edit `openjscad` first line accordingly.

Assuming you cloned the depository:

% git clone
% cd
% make install

Web Browser (Offline)[edit]

Access the local copy of `index.html` with your browser. The initial example should display. You can now open other OpenJSCAD files by dragging and dropping the file to the viewer. Other supported file formats can be converted and displayed as well.

Command-Line Interface (Offline)[edit]

% cd examples
% openjscad logo.jscad
% openjscad logo.jscad -o test.stl
% openjscad logo.jscad -of stl

which creates ``logo.stl`` or ``test.stl``.

Additional you can import OpenSCAD (.scad), STL ASCII or Binary (.stl) and AMF (.amf) files, and create .jscad, .stl (ASCII or Binary), dxf or .amf:

% openjscad example001.scad -o example001.jscad
% openjscad example001.scad -o example001.stl
% openjscad frog.stl -o frog.jscad
% openjscad frog.stl -o frog2.stl             # does actually stl -> jscad -> stl (ascii)
% openjscad example001.jscad -o example001.amf  
% openjscad example001.jscad -of amf          # creates example001.amf
% openjscad example001.jscad -of stlb         # creates example001.stl (binary)
% openjscad example001.jscad -of stlb -o test.stl
  • -o stands for output
  • -of stands for output format (jscad, stl (default), stla, stlb, amf, dxf)

See also how to pass variables from the CLI to main().

Language / File Format Support[edit]

Currently following languages and file-formats are supported:

Format Extension Website Notes
JSCAD .jscad OpenJSCAD is a software for creating solid 3D CAD objects using your browser.
SCAD .scad OpenSCAD is a software for creating solid 3D CAD objects. (Import only)
STL .stl Wikipedia: STL (file format) STL files describe only the surface geometry of three-dimensional objects
AMF .amf Wikipedia: AMF (file format) Additive Manufacturing File Format (very experimental)
DXF .dxf DXF (file format) Drawing Interchange File Format (export only)
X3D .x3d Open standards file format to represent 3D objects using XML.
SVG .svg W3C SVG Standard Scalable Vector Graphics Format

When you drag & drop files, the language or format is set according the file extension (.jscad, etc). When you start to edit directly using your browser, the default language is JSCAD.

Direct Link for Local or Remote JSCAD, SCAD, STL and AMF[edit]

You can give other people a link to a specific example:


  2. http://localhost/

In case you reference a JSCAD file, the include() function is supported.


  2. (STL)
  3. (SCAD)
  4. (AMF)

In case you reference a JSCAD file, the include() function is not supported (perhaps later).

OpenJSCAD Programming Guide[edit]

In general, designs are written using the JavaScript language. Training and help about JavaScript can be found online.

Creating a new design starts by writing simple scripts which call CSG functions, and other special functions, as provided by OpenJSCAD. OpenJSCAD executes the script, and renders the 3D design for viewing.

OpenJSCAD adheres to specific standards for passing parameters to functions. But most parameters are optional as default values are provided.

When 3D vectors are required, parameters can be passed as an array. If a scalar (single value) is passed for a parameter which expects a 3D vector, the scalar is used for the x, y and z values. In other words: radius: 1 will give radius: [1,1,1].


Anatomy of a OpenJSCAD Script[edit]

An OpenJSCAD script must have at least one function defined, the main() function, which has to return a CSG object, or an array of non-intersecting CSG objects.

function main() {
   return union(sphere(), ...);    // an union of objects or
   return [sphere(), ...];        // an array of non-intersecting objects

or like this:

var w = new Array();
function a() {
   w.push( sphere() );
   w.push( cube().translate([2,0,0]) );
function main() {
   return w;

But this does not work.

var w = new Array();
w.push( sphere() );                    // Note: it's not within a function (!!)
w.push( cube().translate([2,0,0]) );

function main() {
    return w;

Because all CSG creations, like 3D primitives, have to occur within functions which are called by the main() function.

3D Primitives[edit]

All rounded solids have a resolution parameter which controls tesselation. If resolution is set to 8, then 8 polygons per 360 degree of revolution are used. Beware that rendering time will increase dramatically when increasing the resolution. For a sphere, the number of polygons increases quadratically with the resolution used. If the resolution parameter is omitted, the following two global defaults are used

  • CSG.defaultResolution2D
  • CSG.defaultResolution3D

The former is used for 2D curves (circle, cylinder), the latter for 3D curves (sphere, 3D expand).

OpenSCAD like functions support the fn parameter, which is the numer of segments to approximate a sphere (default 32, total polygons per sphere fn*fn).



Cube or rather boxes can be created like this:

cube(); // openscad like
cube({size: 1});
cube({size: [1,2,3]});
cube({size: 1, center: true}); // default center:false
cube({size: 1, center: [false,false,false]}); // individual axis center true or false
cube({size: [1,2,3], round: true});

CSG.cube(); // object-oriented
    center: [0, 0, 0],
    radius: [1, 1, 1]

CSG.cube({ // define two opposite corners
    corner1: [0, 0, 0],
    corner2: [5, 4, 2]

CSG.roundedCube({ // rounded cube
    center: [0, 0, 0],
    radius: 1,
    roundradius: 0.2,
    resolution: 8,



Spheres can be created like this:

sphere();                          // openscad like
sphere({r: 2});                    // Note: center:true is default (unlike other primitives, as OpenSCAD)
sphere({r: 2, center: false});     // Note: OpenSCAD doesn't support center for sphere but we do
sphere({r: 2, center: [true, true, false]}); // individual axis center 
sphere({r: 10, fn: 100 });
sphere({r: 10, fn: 100, type: 'geodesic'});  // geodesic approach (icosahedron further triangulated)

CSG.sphere();                      // object-oriented
  center: [0, 0, 0],
  radius: 2,                      // must be scalar
  resolution: 32

In case of ``type: 'geodesic'`` the fn tries to match the non-geodesic fn, yet, actually changes in steps of 6 (e.g. fn=6..11 is the same), fn = 1 reveals the base form: the icosahedron.

Note: Creating spheres with high resolution and then operating with them, e.g. union(), intersection(), etc, slows down rendering / construction procedure due the large amount of polygons.



Cylinders and cones can be created like this:

cylinder({r: 1, h: 10});                 // openscad like
cylinder({d: 1, h: 10});
cylinder({r: 1, h: 10, center: true});   // default: center:false
cylinder({r: 1, h: 10, center: [true, true, false]});  // individual x,y,z center flags
cylinder({r: 1, h: 10, round: true});
cylinder({r1: 3, r2: 0, h: 10});
cylinder({d1: 1, d2: 0.5, h: 10});
cylinder({start: [0,0,0], end: [0,0,10], r1: 1, r2: 2, fn: 50});

CSG.cylinder({                      // object-oriented
  start: [0, -1, 0],
  end: [0, 1, 0],
  radius: 1,                        // true cylinder
  resolution: 16
  start: [0, -1, 0],
  end: [0, 1, 0],
  radiusStart: 1,                   // start- and end radius defined, partial cones
  radiusEnd: 2,
  resolution: 16
CSG.roundedCylinder({               // and its rounded version
  start: [0, -1, 0],
  end: [0, 1, 0],
  radius: 1,
  resolution: 16

whereas fn is the amount of segments to approximate the circular profile of the cylinder (default 32).



A torus is defined as such:

  • ri = inner radius (default: 1),
  • ro = outer radius (default: 4),
  • fni = inner resolution (default: 16),
  • fno = outer resolution (default: 32),
  • roti = inner rotation (default: 0)
torus();                    // ri = 1, ro = 4;  
torus({ ri: 1.5, ro: 3 });
torus({ ri: 0.2 });

torus({ fni:4 });           // make inner circle fn = 4 => square
torus({ fni:4,roti:45 });   // rotate inner circle, so flat is top/bottom
torus({ fni:4,fno:4,roti:45 });
torus({ fni:4,fno:5,roti:45 });


Create a polyhedron with a list of points and a list of triangles or polygons. The point list is all the vertexes of the shape, the triangle list is how the points relates to the surfaces of the polyhedron:

polyhedron({      // openscad-like (e.g. pyramid)
  points: [ [10,10,0],[10,-10,0],[-10,-10,0],[-10,10,0], // the four points at base
            [0,0,10] ],                                  // the apex point 
  triangles: [ [0,1,4],[1,2,4],[2,3,4],[3,0,4],          // each triangle side
               [1,0,3],[2,1,3] ]                         // two triangles for square base

Additionally you can also define `polygons: [ [0,1,4,5], [..] ]` too, not just `triangles:`.

You can also create a polyhedron at a more low-level and object-oriented:

var polygons = [];
polygons.push(new CSG.Polygon([
      new CSG.Vertex(new CSG.Vector3D(-5,-5,0)),
      new CSG.Vertex(new CSG.Vector3D(2,2,5)),
      new CSG.Vertex(new CSG.Vector3D(3,3,15))
// add more polygons and finally:
solid = CSG.fromPolygons(polygons);


``vector_text(x,y,string)`` and ``vector_char(x,y,char)`` give you line segments of a text or character rendered in vector:

var l = vector_text(0,0,"Hello World!");   // l contains a list of polylines to be drawn
var o = [];
l.forEach(function(pl) {                   // pl = polyline (not closed)
   o.push(rectangular_extrude(pl, {w: 2, h: 2}));   // extrude it to 3D
return union(o);

Also multiple-line with "\n" is supported, for now just left-align is supported. If you want to dive more into the details, you can request a single character:

var c = vector_char(x,y,"A");
c.width;    // width of the vector font rendered character
c.segments; // array of segments / polylines

3D Transformations[edit]


var obj = sphere(5);
scale(2,obj);          // openscad like
scale([1,2,3],obj);    //      '' 

obj.scale([1,2,3]);    // object-oriented


var obj = cube([5,20,5]);
rotate([90,15,30],obj);       // openscad like
rotate(90,[1,0.25,0.5],obj);  //    ''

obj.rotateX(90);              // object-oriented


translate([0,0,10],obj);  // openscad like

obj.translate([0,0,10]);  // object-oriented


Centering an object altogether or axis-wise:

center(true,cube());                // openscad-like all axis
center([true,true,false],cube());   // openscad-like axis-wise [x,y]

// false = do nothing, true = center axis

cube().center();                // object oriented center all axis
cube().center('x','y');         // object oriented center axis-wise [x,y]

It center() and .center() helps you to compose a symmetric whose complete size you don't know when composing, e.g. from parametric design.

Matrix Operations[edit]

var m = new CSG.Matrix4x4();
m = m.multiply(CSG.Matrix4x4.rotationX(40));
m = m.multiply(CSG.Matrix4x4.rotationZ(40));
m = m.multiply(CSG.Matrix4x4.translation([-.5, 0, 0]));
m = m.multiply(CSG.Matrix4x4.scaling([1.1, 1.2, 1.3]));

// and apply the transform:
var cube3 = cube.transform(m);


mirror([10,20,90], cube(1)); // openscad like

var cube = CSG.cube().translate([1,0,0]);   // object-oriented

var cube2 = cube.mirroredX(); // mirrored in the x=0 plane
var cube3 = cube.mirroredY(); // mirrored in the y=0 plane
var cube4 = cube.mirroredZ(); // mirrored in the z=0 plane

// create a plane by specifying 3 points:
var plane = CSG.Plane.fromPoints([5,0,0], [5, 1, 0], [3, 1, 7]);

// and mirror in that plane:
var cube5 = cube.mirrored(plane);


union(sphere({r: 1, center:true}),cube({size: 1.5, center:true}));  // openscad like

multiple objects can be added, also arrays.

sphere({r: 1, center:true}).union(cube({size: 1.5, center:true}));  // object-oriented


intersection(sphere({r: 1, center:true}),cube({size: 1.5, center:true})); // openscad like

multiple objects can be intersected, also arrays.

sphere({r: 1, center:true}).intersect(cube({size: 1.5, center:true}));   // object-oriented

Note intersection() (openscad like) vs intersect() (method, object-oriented)

Difference (Subtraction)[edit]

difference(sphere({r: 1, center:true}),cube({size: 1.5, center:true}));    // openscad like

multiple objects can be differentiated (subtracted) from the first element, also arrays.

sphere({r: 1, center:true}).subtract(cube({size: 1.5, center:true}));      // object-oriented

Note: difference() (openscad like) vs subtract() (method, object-oriented)

2D Primitives[edit]


circle();                        // openscad like
circle({r: 2, fn:5});
circle({r: 3, center: true});    // center: false (default){center: [0,0], radius: 3, resolution: 32});   // object-oriented

Square / Rectangle[edit]

square();                                   // openscad like
square(1);                                  // 1x1
square([2,3]);                              // 2x3
square({size: [2,4], center: true});        // 2x4, center: false (default)

CAG.rectangle({center: [0,0], radius: [w/2, h/2]});   // object-oriented, whereas w or h = side-length of square
CAG.roundedRectangle({center: [0,0], radius: [w/2, h/2], roundradius: 1, resolution: 4});


polygon([ [0,0],[3,0],[3,3] ]);                // openscad like
polygon({ points: [ [0,0],[3,0],[3,3] ] });                    
polygon({ points: [ [0,0],[3,0],[3,3],[0,6] ], paths: [ [0,1,2],[1,2,3] ] }); // multiple paths not yet implemented

var shape1 = CAG.fromPoints([ [0,0],[5,0],[3,5],[0,5] ]);    // object-oriented

2D Transformations[edit]

translate([2,2], circle(1));      // openscad like
rotate([0,0,90], square());       //     ''
shape = center(true, shape());    // center both axis
shape = center([true,false], shape()); // center axis-wise [x] 

shape = shape.translate([-2, -2]);   // object-oriented
shape = shape.rotateZ(20);
shape = shape.scale([0.7, 0.9]);
shape =;          // center both axis
scape ='x');       // center axis-wise [x]

2D Paths[edit]

A path is simply a series of points, connected by lines. A path can be open or closed (an additional line is drawn between the first and last point). 2D paths are supported through the CSG.Path2D class. The difference between a 2D Path and a 2D CAG is that a path is a 'thin' line, whereas a CAG is an enclosed area.

Paths can be constructed either by giving the constructor an array of 2D coordinates, or through the various CSG.Path2D member functions, which include:

  • arc(endpoint, options): return a circular or ellipsoid curved path (see example below for usage).
  • appendPoint([x,y]): create & return a new Path2D containing the callee's points followed by the given point.
  • appendPoints([[x,y],...]): create & return a new Path2D containing the callee's points followed by the given points. [Note: as of 2016/08/13, this method also modifies the callee; this is probably a bug and might be changed in the future; see issue:165]
  • appendBezier([[x,y],...], options): create & return a new Path2D containing the callee's points followed by a Bezier curve ending at the last point given; all but the last point given are the control points of the Bezier; a null initial control point means use the last two points of the callee as control points for the new Bezier curve. options can specify {resolution: <NN>}.

Paths can be concatenated with .concat(), the result is a new path.

A path can be converted to a CAG in two ways:

  • expandToCAG(pathradius, resolution) traces the path with a circle, in effect making the path's line segments thick.
  • innerToCAG() creates a CAG bounded by the path. The path should be a closed path.

Creating a 3D solid is currently supported by the rectangularExtrude() function. This creates a 3D shape by following the path with a 2D rectangle (upright, perpendicular to the path direction):

var path = new CSG.Path2D([ [10,10], [-10,10] ], /* closed = */ false);
var anotherpath = new CSG.Path2D([ [-10,-10] ]);
path = path.concat(anotherpath);
path = path.appendPoint([10,-10]);
path = path.close(); // close the path

// of course we could simply have done:
// var path = new CSG.Path2D([ [10,10], [-10,10], [-10,-10], [10,-10] ], /* closed = */ true);

// We can make arcs and circles:
var curvedpath = CSG.Path2D.arc({
  center: [0,0,0],
  radius: 10,
  startangle: 0,
  endangle: 180,
  resolution: 16,



You can convex hull multiple 2D polygons (e.g. circle(), square(), polygon()) together.

var h = hull( square(10),circle(10).translate([10,10,0]) );

linear_extrude({ height: 10 }, h);

Chain Hull[edit]

Openjscad-chain hull.png

Chained hulling is a variant of hull on multiple 2D forms, essentially sequential hulling and then union those, based on an idea by Whosa whatsis:

    circle(), circle().translate([2,0,0]), ... );   // list of CAG/2D forms

var a = [];
chain_hull( a );                       // array of CAG/2D forms

chain_hull({closed: true},             // default is false

Extruding / Extrusion[edit]

Linear Extrude[edit]

Openjscad-linear extrude.png

Extruding 2D shapes into 3D, given height, twist (degrees), and slices (if twist is made):

// openscad like
linear_extrude({ height: 10 }, square());
linear_extrude({ height: 10, twist: 90 }, square([1,2]));
linear_extrude({ height: 10, twist: 360, slices: 50}, circle().translate([1,0,0]) );

linear_extrude({ height: 10, center: true, twist: 360, slices: 50}, translate([2,0,0], square([1,2])) );
linear_extrude({ height: 10, center: true, twist: 360, slices: 50}, square([1,2]).translate([2,0,0]) );

Linear extrusion of 2D shape, with optional twist. The 2d shape is placed in in z=0 plane and extruded into direction <offset> (a CSG.Vector3D). The final face is rotated <twistangle> degrees. Rotation is done around the origin of the 2d shape (i.e. x=0, y=0) twiststeps determines the resolution of the twist (should be >= 1), returns a CSG object:

// object-oriented
var c ={radius: 3});
extruded = c.extrude({offset: [0,0,10], twistangle: 360, twiststeps: 100});

Rectangular Extrude[edit]

Openjscad-rectangular extrude.png

Extrude the path by following it with a rectangle (upright, perpendicular to the path direction), returns a CSG solid.

Simplified (openscad like, even though OpenSCAD doesn't provide this) via rectangular_extrude(), where as

  • w: width (default: 1),
  • h: height (default: 1),
  • fn: resolution (default: 8), and
  • closed: whether path is closed or not (default: false)
rectangular_extrude([ [10,10], [-10,10], [-20,0], [-10,-10], [10,-10] ],  // path is an array of 2d coords
    {w: 1, h: 3, closed: true});

or more low-evel and object-oriented via rectangularExtrude(), with following unnamed variables:

  1. width of the extrusion, in the z=0 plane
  2. height of the extrusion in the z direction
  3. resolution, number of segments per 360 degrees for the curve in a corner
  4. roundEnds: if true, the ends of the polygon will be rounded, otherwise they will be flat
// first creating a 2D path, and then extrude it
var path = new CSG.Path2D([ [10,10], [-10,10], [-20,0], [-10,-10], [10,-10] ], /*closed=*/true);
var csg = path.rectangularExtrude(3, 4, 16, true);   // w, h, resolution, roundEnds
return csg;

Rotate Extrude[edit]

Openjscad-rotate extrude.png

Additional also rotate_extrude() is available:

// openscad-like
rotate_extrude( translate([4,0,0], circle({r: 1, fn: 30, center: true}) ) );

// more object-oriented
rotate_extrude({fn:4}, square({size: [1,1], center: true}).translate([4,0,0]) );

rotate_extrude( polygon({points:[ [0,0],[2,1],[1,2],[1,3],[3,4],[0,5] ]}) );
rotate_extrude({fn:4}, polygon({points:[ [0,0],[2,1],[1,2],[1,3],[3,4],[0,5] ]}) );

You can essentially extrude any 2D polygon (circle, square or polygon).


The 'property' property of a solid can be used to store metadata for the object, for example the coordinate of a specific point of interest of the solid. Whenever the object is transformed (i.e. rotated, scaled or translated), the properties are transformed with it. So the property will keep pointing to the same point of interest even after several transformations have been applied to the solid.

Properties can have any type, but only the properties of classes supporting a 'transform' method will actually be transformed. This includes CSG.Vector3D, CSG.Plane and CSG.Connector. In particular CSG.Connector properties (see below) can be very useful: these can be used to attach a solid to another solid at a predetermined location regardless of the current orientation.

It's even possible to include a CSG solid as a property of another solid. This could be used for example to define the cutout cylinders to create matching screw holes for an object. Those 'solid properties' get the same transformations as the owning solid but they will not be visible in the result of CSG operations such as union().

Other kind of properties (for example, strings) will still be included in the properties of the transformed solid, but the properties will not get any transformation when the owning solid is transformed.

All primitive solids have some predefined properties, such as the center point of a sphere (TODO: document).

The solid resulting from CSG operations (union(), subtract(), intersect()) will get the merged properties of both source solids. If identically named properties exist, only one of them will be kept.

var cube = CSG.cube({radius: 1.0}); = new CSG.Vector3D([1, 1, 1]);
cube = cube.translate([5, 0, 0]);
cube = cube.scale(2);
// will now point to [12, 2, 2],
// which is still the same corner point 

// Properties can be stored in arrays; all properties in the array
// will be transformed if the solid is transformed: = [
  new CSG.Vector3D([-1, 1, 1]),
  new CSG.Vector3D([-1, -1, 1])

// and we can create sub-property objects; these must be of the 
// CSG.Properties class. All sub properties will be transformed with
// the solid: = new CSG.Properties(); = new CSG.Vector3D([-1, -1, -1]);


The CSG.Connector class is intended to facilitate attaching two solids to each other at a predetermined location and orientation. For example suppose we have a CSG solid depicting a servo motor and a solid of a servo arm: by defining a Connector property for each of them, we can easily attach the servo arm to the servo motor at the correct position (i.e. the motor shaft) and orientation (i.e. arm perpendicular to the shaft) even if we don't know their current position and orientation in 3D space.

In other words Connector give us the freedom to rotate and translate objects at will without the need to keep track of their positions and boundaries. And if a third party library exposes connectors for its solids, the user of the library does not have to know the actual dimensions or shapes, only the names of the connector properties.

A CSG.Connector consist of 3 properties:

  • point: a CSG.Vector3D defining the connection point in 3D space
  • axis: a CSG.Vector3D defining the direction vector of the connection (in the case of the servo motor example it would point in the direction of the shaft)
  • normal: a CSG.Vector3D direction vector somewhat perpendicular to axis; this defines the "12 o'clock" orientation of the connection.

When connecting two connectors, the solid is transformed such that the point properties will be identical, the axis properties will have the same direction (or opposite direction if mirror == true), and the normals match as much as possible.

Connectors can be connected by means of two methods: A CSG solid's connectTo() function transforms a solid such that two connectors become connected. Alternatively we can use a connector's getTransformationTo() method to obtain a transformation matrix which would connect the connectors. This can be used if we need to apply the same transform to multiple solids.

var cube1 = CSG.cube({radius: 10});
var cube2 = CSG.cube({radius: 4});

// define a connector on the center of one face of cube1
// The connector's axis points outwards and its normal points
// towards the positive z axis: = new CSG.Connector([10, 0, 0], [1, 0, 0], [0, 0, 1]);

// define a similar connector for cube 2: = new CSG.Connector([0, -4, 0], [0, -1, 0], [0, 0, 1]);

// do some random transformations on cube 1:
cube1 = cube1.rotateX(30);
cube1 = cube1.translate([3.1, 2, 0]);

// Now attach cube2 to cube 1:
cube2 = cube2.connectTo(,, 
  true,   // mirror 
  0       // normalrotation

// Or alternatively:
var matrix =, 
  true,   // mirror 
  0       // normalrotation
cube2 = cube2.transform(matrix);

var result = cube2.union(cube1);

Bounds & Surface Laying[edit]

The getBounds() function can be used to retrieve the bounding box of an object, returning an array with two CSG.Vector3Ds specifying the minimum X,Y,Z coordinates and the maximum X,Y,Z coordinates.

The lieFlat() function lays an object onto the Z surface, in such a way that the Z-height is minimized and the object is centered around the Z axis. This can be useful for CNC milling, allowing an object to be transform into the space of the stock material during milling. Or for 3D printing: it is laid in such a way that it can be printed with minimal number of layers. Instead of the lieFlat() function, the getTransformationToFlatLying() function can be used, which returns a CSG.Matrix4x4 for the transformation.

var cube1 = CSG.cube({radius: 10});
var cube2 = CSG.cube({radius: 5});

// get the right bound of cube1 and the left bound of cube2:
var deltax = cube1.getBounds()[1].x - cube2.getBounds()[0].x;

// align cube2 so it touches cube1:
cube2  = cube2.translate([deltax, 0, 0]);

var cube3 = CSG.cube({radius: [100,120,10]});
// do some random transformations:
cube3 = cube3.rotateZ(31).rotateX(50).translate([30,50,20]);
// now place onto the z=0 plane:
cube3  = cube3.lieFlat();

// or instead we could have used:
var transformation = cube3.getTransformationToFlatLying();
cube3 = cube3.transform(transformation);

return cube3;



color([r,g,b], object, object2 ...); // for example, color([1,1,0],sphere());
color([r,g,b], array);
color([r,g,b,a], object, object2 ...);
color([r,g,b,a], array);
color(name, object, object2 ...); // for example, color('red',sphere());
color(name, a, object, object2 ...); // for example, color('red',0.5, sphere());
color(name, array);
color(name, a, array);

Whereas the named colors are case-insensitive, e.g. 'RED' is the same as 'red'.




color([1,0.5,0.3],sphere(1));                      // openscad like
color("Red",sphere(),cube().translate([2,0,0]));   // named color (case-insensitive)

sphere().setColor(1,0.5,0.3);                      // object-oriented

See Wikipedia: Web Colors for all available named colors sorted by tone.


Code excerpt:

o.push( color([1,0,0],sphere()) );
o.push( color([0,1,0],cube()) );
o.push( color([0,0,1],cylinder()) );

o.push( color("red",sphere()) );
o.push( color("green", cube()) );
o.push( color("blue", cylinder()) );

for(var i=0; i&lt;1; i+=1/12) {
   o.push( cube().setColor(hsl2rgb(i,1,0.5)) );


function main() {
   var o = [];
   for(var i=0; i&lt;8; i++) {
            hsl2rgb(i/8,1,0.5).  // hsl to rgb, creating rainbow [r,g,b]
            concat(1/8+i/8)      // and add to alpha to make it [r,g,b,a]
   return o;

Note: There are some OpenGL Transparency Limitations, e.g. and depending on the order of colors, you might not see through otherwise partially transparent objects.

Color Spacing Conversion[edit]

Following functions to convert between color spaces:

var hsl = rgb2hsl(r,g,b); // or rgb2hsl([r,g,b]);
var rgb = hsl2rgb(h,s,l); // or hsl2rgb([h,s,l]);
var hsv = rgb2hsv(r,g,b); // or rgb2hsv([r,g,b]);
var rgb = hsv2rgb(h,s,v); // or hsv2rgb([h,s,v]);


  • r,g,b (red, green, blue)
  • h,s,l (hue, saturation, lightness)
  • h,s,v (hue, saturation, value)

E.g. to create a rainbow, t = 0..1 and .setColor(hsl2rgb(t,1,0.5))


See the Tor (multi-color) for an example.


a = 1, b = 2;

prints out on the JavaScript console: a=1, b=2

Mathematical Functions[edit]

Javascript provides several functions through the Math library. In addition, the following OpenSCAD compatible functions are available:

sin(a);                   // a = 0..360
cos(a);                   //     ''
asin(a);                  // a = 0..1, returns 0..360
acos(a);                  //       ''
tan(a);                   // a = 0..360
atan(a);                  // a = 0..1, returns 0..360
atan2(a,b);               // returns 0..360
rands(min,max,vn,seed);   // returns random vectors of vn dimension, seed not yet implemented
lookup(ix,v);             // ix = index, e.g. v = [ [0,100], [10,10], [20,200] ] whereas v[x][0] = index, v[x][1] = value
                          //    return will be linear interpolated (e.g. lookup(5,[ [0,100], [10,10], [20,200] ]) == 45

sign(a);                  // -1, 0 or 1

Direct OpenSCAD Source Import[edit]

An OpenSCAD to OpenJSCAD translator is included, however the following features aren't working yet:

  • DXF import and manipulation (e.g. import_dxf, dxf-cross, dxf_dim functions).
  • rotate_extrude() (Note: OpenJSCAD supports rotate_extrude() )
  • minkowski() and hull() transformations (Note: OpenJSCAD supports hull() )
  • global variable such as $fa, $fs
  • Modifier characters: #, !, %
  • List Comprehension such as: list = [ for (i = [2, 3, 5, 7, 11]) i * i ];

You can edit OpenSCAD source in the built-in editor, just make sure the first line says:


then the source-code is shown with OpenSCAD syntax.

Further CAD languages support might arrive at a later time.

Converting OpenSCAD to OpenJSCAD[edit]

In order to translate your OpenSCAD into native OpenJSCAD code, consider this comparison.


union() {
      translate([3,0,0]) cube();
      difference() {
         rotate([0,-45,0]) cube(size=[8,7,3],center=true);
      translate([10,5,5]) scale([0.5,1,2]) sphere(r=5,$fn=50);
      translate([-15,0,0]) cylinder(r1=2,r2=0,h=10,$fn=20);
   for(i=[0:19]) {


function main() {  
   var cubes = new Array();
   for(i=0; i&lt;20; i++) {
      cubes[i] = rotate([0,i/20*360,0], 
   return union(
         rotate([0,-45,0], cube({size:[8,7,3],center:true})),
      translate([10,5,5], scale([0.5,1,2], sphere({r:5,fn:50}))),
      translate([-15,0,0], cylinder({r1:2,r2:0,h:10,fn:20})),

Essentially whenever named arguments in OpenSCAD appear func(a=1), translate it into func({a:1}), for example:

// OpenSCAD
translate([0,0,2]) sphere(size=2,$fn=50)
// becomes OpenJSCAD
translate([0,0,2], sphere({size:2,fn:50}));
// or

Interactive Parametric Models[edit]


Models can have interactive parameters, allowing users to change values via familiar forms, i.e. typing in numbers, sliding bars, pulling down menus, etc. This allows the user to change values and create any number of possible combinations, allowing the model to become dynamic in nature. Any number of custom designs can be created, which can then be down loaded in any supported format.

Interactive parameters are possible by adding a specific function called getParameterDefinitions(). This function can be added anywhere in to your JSCAD script, but must return an array of parameter definitions.

function getParameterDefinitions() {
  return [{ name: 'width', type: 'float', initial: 10, caption: "Width of the cube:" }];

The parameter definitions are used to create a set of fields which the user can change, i.e. options. The values of the fields are supplied to the main() function of your JSCAD script. For example, the value of the 'width' parameter is supplied as the 'params.width' attribute, and so on.

function main(params) {
  // custom error checking:
  if(params.width &lt;= 0) throw new Error("Width should be positive!");
  var mycube = CSG.cube({radius: params.width});
  return mycube();

All the common HTML5 field types are available as interactive parameters. This includes checkbox (boolean), color, date, email, float, int, number, password, slider, text and url. As well as two special parameter types for pull down choices, and grouping parameters.

A minimum parameter specification contains only 'name' and 'type'. However, a complete parameter specification should have a 'caption' and 'initial' value. In addition, there are 'min', 'max', 'step', 'checked', 'size, 'maxlength', and 'placeholder' which are relevant to specific parameter types. Just keep try different combinations to get a nice parameter specification. Here's an good example.

  name: 'width',
  type: 'float',
  initial: 1.5,
  caption: 'Width of the thingy:',
  min: 1.0,
  max: 5.0,
  step: 0.5

In addition, there is the 'choice' type which creates a drop down list of choices for the user. The choices are provided by specifying the 'values' and 'captions'. The chosen value is passed into the main() function of the model.

  name: 'shape',
  type: 'choice',
  values: ["TRI", "SQU", "CIR"],               // these are the values that will be supplied to your script
  captions: ["Triangle", "Square", "Circle"],  // optional, these values are shown in the listbox
                                               // if omitted, the items in the 'values' array are used
  caption: 'Shape:',                           // optional, displayed left of the input field
  initial: "SQU",                              // optional, default selected value
                                               // if omitted, the first item is selected by default
                                               // NOTE: parameter "default" is deprecated

A complete example:

function getParameterDefinitions() {
  return [
    { name: 'width', type: 'float', initial: 10, caption: "Width of the cube:" },
    { name: 'height', type: 'float', initial: 14, caption: "Height of the cube:" },
    { name: 'depth', type: 'float', initial: 7, caption: "Depth of the cube:" },
    { name: 'rounded', type: 'choice', caption: 'Round the corners?', values: [0, 1], captions: ["No thanks", "Yes please"], initial: 1 }

function main(params) {
  var result;
  if(params.rounded == 1) {
    result = CSG.roundedCube({radius: [params.width, params.height, params.depth], roundradius: 2, resolution: 32});
  } else {
    result = CSG.cube({radius: [params.width, params.height, params.depth]});
  return result;

There are plenty of examples of "Interactive" parameters available at See the Quick Reference for more information about the available parameter types, and browser support.

Parameters via the Command Line Interface[edit]

The command line interface, ``openjscad``, can pass parameters for the interactive designs. Either by

 key value



For example:

% openjscad name_plate.jscad --name "Just Me" --title "Geek" -o JustMe.amf
% openjscad name_plate.jscad "--name=Just Me" "--title=Geek" -o JustMe.amf

Maintaining Larger Projects[edit]

Including Files[edit]

After creating a few designs using OpenJSCAD, common functions and parts will become useful. The include() function allows one OpenJSCAD script to include another OpenJSCAD script.

// main.jscad

function main() {
   return myLib().b(2);


// lib.jscad
myLib = function() {
   var a = function(n) {  // internal 
      return n*2;  
   myLib.b = function(n) {      // public 
      return sphere(a(n));  

See Example 50: Platonics with a recursive use of include(). Yet, it's a rather bad example of not localize the function names. A clear writing style-guide will follow how an OpenJSCAD library should look like.

Support of include()[edit]

The include() function is supported

  • web-online remote (e.g. given you drag & dropped the files, or they are available on the web-server (e.g. the examples)
  • web-online local (e.g. http://localhost/OpenJSCAD/): given you drag & dropped the files, or they are available on the local web-server
  • web-offline local (e.g. file://..../OpenJSCAD/index.html): given you drag & dropped the files
  • command-line interface (CLI): given they are locally available in the filesystem

Example of a setup with drag & dropped files:


File Layout of JSCAD Projects[edit]

Assuming you want to create a larger OpenJSCAD project, you might use include() to split up the functionality:

   main.jscad          # this one contains the "function main()", this file will be <b>executed</b>
   addon.jscad         # this file could be include("addon.jscad") in main.jscad
   optimizer.jscad     #             ''     include("optimizer.jscad") in main.jscad or also in addon.jscad 
   Makefile            # possible Makefile to do the same on CLI

Note: The file named main.jscad must be present, and must contain the "function main()" declaration.

Developing with Multiple JSCAD Files[edit]

Depending on your browser and your local setup, following applies:

  • Chrome (Version 26):
* Online (http://...): drag & drop entire folder, e.g. ProjectName/ to the drag & drop zone
* Offline (file://...): drag & drop all jscad files (but not folder) to the drag & drop zone
  • Firefox (Version 19+): drag & drop all jscad files of the project to the drag & drop zone
  • Opera: not yet working (WebGL support not yet available)
  • IE10: not yet working (WebGL support not yet available)