OpenJsCad/index.html
2012-02-13 18:19:37 +01:00

426 lines
15 KiB
HTML

<!DOCTYPE html>
<html><head>
<script src="lightgl.js"></script>
<script src="csg.js"></script>
<script src="openjscad.js"></script>
<style>
body {
font: 14px/20px 'Helvetica Neue Light', HelveticaNeue-Light, 'Helvetica Neue', Helvetica, Arial, sans-serif;
max-width: 820px;
margin: 0 auto;
padding: 10px;
}
pre, code, textarea {
font: 12px/20px Monaco, monospace;
border: 1px solid #CCC;
border-radius: 3px;
background: #F9F9F9;
padding: 0 3px;
color: #555;
}
pre, textarea {
padding: 10px;
width: 100%;
}
textarea {
height: 200px;
}
textarea:focus {
outline: none;
}
canvas { cursor: move; }
</style>
<script>
var gProcessor=null;
// Show all exceptions to the user:
OpenJsCad.AlertUserOfUncaughtExceptions();
function onload()
{
gProcessor = new OpenJsCad.Processor(document.getElementById("viewer"));
updateSolid();
}
function updateSolid()
{
gProcessor.setJsCad(document.getElementById('code').value);
}
</script>
<title>OpenJsCad</title>
</head>
<body onload="onload()">
<h1>OpenJsCad</h1>
Create an STL file for 3D printing using constructive solid modeling in Javascript.
<div id="viewer"></div>
<h2>Playground</h2>
Try it by entering some code below. Anything you enter will be lost as soon as this page is reloaded;
to build your own models you should instead store them in a .jscad file on your computer
and use the <a href="processfile.html"><b>OpenJsCad parser</b></a>.
<br><br>
<textarea id="code">
function main()
{
var resolution = 16; // increase to get smoother corners (will get slow!)
var cube1 = CSG.roundedCube({center: [0,0,0], radius: [10,10,10], roundradius: 2, resolution: resolution});
var sphere1 = CSG.sphere({center: [5, 5, 5], radius: 10, resolution: resolution });
var sphere2 = sphere1.translate([12, 5, 0]);
var sphere3 = CSG.sphere({center: [20, 0, 0], radius: 30, resolution: resolution });
var result = cube1;
result = result.union(sphere1);
result = result.subtract(sphere2);
result = result.intersect(sphere3);
return result;
}
</textarea><br>
<input type="submit" value="Update" onclick="updateSolid(); return false;">
<br>
<h1>About</h1>
This is intended to become a Javascript based alternative to <a href="http://www.openscad.org/">OpenSCAD</a>,
for 3D solid modeling.
CSG model is contructed using Javascript. For example:<br>
<pre>function main() {
var cube = CSG.cube();
return cube;
}</pre>
creates a cube with a radius of 1 and centered at the origin.
The code should always contain a main() function, returning a CSG solid.
<br><br>
To build your own models, create a .jscad file with your javascript code and parse the file using the
<a href="processfile.html">OpenJsCad parser</a>. When finished, click on Generate STL and save the result
in an .stl file, ready to be printed on your 3d printer.
<h2>License</h2>
Copyright (c) 2012 Joost Nieuwenhuijse.
Uses CSG.js, <a href="https://github.com/evanw/csg.js">original</a> copyright (c) 2011 Evan Wallace,
<a href="https://github.com/joostn/csg.js">extensively modified</a>, copyright (c) 2012 Joost Nieuwenhuijse.
Uses <a href="https://github.com/evanw/lightgl.js">lightgl.js</a> by Evan Wallace for WebGL rendering.
All code released under MIT license.
<br><br>
Contributions are welcome! It's all written in Javascript, so if you know how to use it you
know how to modify it as well.<br><br>
To contribute go to <a href="https://github.com/joostn/csg.js">CSG.js at GitHub</a>,
<a href="http://help.github.com/fork-a-repo/">create your own fork</a> and
<a href="http://help.github.com/send-pull-requests/">send me a pull request</a>.
<h2>Viewer navigation</h2>
Click and drag to rotate the model around the origin.<br>
Shift+Drag moves the model around.<br>
Alt+drag zooms (by changing the distance between camera and model).
<h2>Primitive solids</h2>
Currently the following solids are supported. The parameters are passed in an object; most
parameters are optional. 3D vectors can be passed in an array. If a scalar is passed
for a parameter which expects a 3D vector, it is used for the x, y and z value.
In other words: <code>radius: 1</code> will give <code>radius: [1,1,1]</code>.
<br><br>
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.
<br><br>
<pre>
// a cube:
var cube = CSG.cube({
center: [0, 0, 0],
radius: [1, 1, 1]
});
// a sphere:
var sphere = CSG.sphere({
center: [0, 0, 0],
radius: 2, // must be scalar
resolution: 32
});
// a cylinder:
var cylinder = CSG.cylinder({
start: [0, -1, 0],
end: [0, 1, 0],
radius: 1,
resolution: 16
});
// like a cylinder, but with spherical endpoints:
var roundedCylinder = CSG.roundedCylinder({
start: [0, -1, 0],
end: [0, 1, 0],
radius: 1,
resolution: 16
});
// a rounded cube:
var cube = CSG.roundedCube({
center: [0, 0, 0],
radius: 1,
roundradius: 0.2,
resolution: 8,
});
</pre>
<h2>CSG operations</h2>
The 3 standard CSG operations are supported. All CSG operations return a new solid; the source solids
are not modified:
<pre>
var csg1 = cube.union(sphere);
var csg2 = cube.intersect(sphere);
var csg3 = cube.subtract(sphere);
</pre>
<h2>Transformations</h2>
Solids can be translated, scaled and rotated. Multiple transforms can be combined into a single matrix transform:
<pre>
var cube = CSG.cube();
// translation:
var cube2 = cube.translate([1, 2, 3]);
// scaling:
var largecube = cube.scale(2.0);
var stretchedcube = cube.scale([1.5, 1, 0.5]);
// rotation:
var rotated1 = cube.rotateX(-45); // rotate around the X axis
var rotated2 = cube.rotateY(90); // rotate around the Y axis
var rotated3 = cube.rotateZ(20); // rotate around the Z axis
// combine multiple transforms into a single matrix transform:
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);
</pre>
<h2>Mirroring</h2>
Solids can be mirrored in any plane in 3D space:
<pre>
var cube = CSG.cube().translate([1,0,0]);
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);
</pre>
<h2>Cutting by a plane</h2>
A solid can be cut by a plane; only the part on the back side is kept:
<pre>
var cube = CSG.cube({radius: 10});
// create a plane by specifying 3 points:
var plane1 = CSG.Plane.fromPoints([5,0,0], [7, 1, 0], [3, 1, 7]);
// or by specifying a normal and a point on the plane:
var plane2 = CSG.Plane.fromNormalAndPoint([3, 1, 2], [5, 0, 0]);
// and cut by the plane:
var part1 = cube.cutByPlane(plane2);
// or if we need the other half of the cube:
var part2 = cube.cutByPlane(plane2.flipped());
</pre>
<h2>Expansion and contraction</h2>
Expansion can be seen
as the 3D convolution of an object with a sphere. Contraction is the reverse: the area outside the solid
is expanded, and this is then subtracted from the solid.
<br><br>
Expansion and contraction are very powerful ways to get an object with nice smooth corners. For example
a rounded cube can be created by expanding a normal cube.
<br><br>
Note that these are expensive operations: spheroids are created around every corner and edge in the original
object, so the number of polygons quickly increases. Expansion and contraction therefore are only practical for simple
non-curved objects.
<br><br>
expand() and contract() take two parameters: the first is the radius of expansion or contraction; the second
parameter is optional and specififies the resolution (number of polygons on spherical surfaces, per 360 degree revolution).
<pre>
var cube1 = CSG.cube({radius: 1.0});
var cube2 = CSG.cube({radius: 1.0}).translate([-0.3, -0.3, -0.3]);
var csg = cube1.subtract(cube2);
var rounded = csg.expand(0.2, 8);
</pre>
<h2>Using Properties</h2>
The 'property' property of a solid can be used to store metdata 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.
<br><br>
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.
<br><br>
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().
<br><br>
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. <br><br>
All primitive solids have some predefined properties, such as the center point
of a sphere (TODO: document).
<br><br>
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.
<pre>
var cube = CSG.cube({radius: 1.0});
cube.properties.aCorner = new CSG.Vector3D([1, 1, 1]);
cube = cube.translate([5, 0, 0]);
cube = cube.scale(2);
// cube.properties.aCorner 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:
cube.properties.otherCorners = [
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:
cube.properties.myProperties = new CSG.Properties();
cube.properties.myProperties.someProperty = new CSG.Vector3D([-1, -1, -1]);
</pre>
<h2>Connectors</h2>
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.<br><br>
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.
<br><br>
A CSG.Connector consist of 3 properties:<br>
<b>point</b>: a CSG.Vector3D defining the connection point in 3D space<br>
<b>axis</b>: 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)<br>
<b>normal</b>: a CSG.Vector3D direction vector somewhat perpendicular to axis; this
defines the &quot;12 o'clock&quot; orientation of the connection.
<br><br>
When connecting two connectors, the solid is transformed such that the <b>point</b>
properties will be identical, the <b>axis</b> properties will have the same direction
(or opposite direction if mirror == true), and the <b>normal</b>s match as much as possible.
<br><br>
Connectors can be connected by means of two methods:<br>
A CSG solid's <b>connectTo()</b> function transforms a solid such that two connectors
become connected.<br>
Alternatively we can use a connector's <b>getTransformationTo()</b> 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.
<pre>
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:
cube1.properties.myConnector = new CSG.Connector([10, 0, 0], [1, 0, 0], [0, 0, 1]);
// define a similar connector for cube 2:
cube2.properties.myConnector = 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(
cube2.properties.myConnector,
cube1.properties.myConnector,
true, // mirror
0 // normalrotation
);
// Or alternatively:
var matrix = cube2.properties.myConnector.getTransformationTo(
cube1.properties.myConnector,
true, // mirror
0 // normalrotation
);
cube2 = cube2.transform(matrix);
var result = cube2.union(cube1);
</pre>
<h2>Determining the bounds of an object</h2>
The getBounds() function can be used to retrieve the bounding box of an object.
getBounds() returns
an array with two elements specifying the minimum x,y,z coordinate and the maximum x,y,z coordinate:
<pre>
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]);
return cube1.union(cube2);
</pre>
<h2>2D shapes</h2>
Two dimensional shapes can be defined through the Polygon2D class. Currently this requires the polygon to be convex
(i.e. all corners less than 180 degrees). Shapes can be transformed (rotation, translation, scaling).
To actually use the shape it needs to be extruded into a 3D CSG object through the extrude() function. extrude()
places the 2D solid onto the z=0 plane, and extrudes in the specified direction. Extrusion can be done with an optional
twist. This rotates the solid around the z axis (and not necessariy around the extrusion axis) during extrusion.
The total degrees of rotation is specified in the twistangle parameter, and twiststeps determine the number of steps
between the bottom and top surface.
<pre>
// Create a shape; argument is an array of 2D coordinates
// The shape must be convex, can be specified in clockwise or in counterclockwise direction
var shape2d=new CSG.Polygon2D([[0,0], [5,0], [3,5], [0,5]]);
// Do some transformations:
shape2d=shape2d.translate([-2, -2]);
shape2d=shape2d.rotate(20);
shape2d=shape2d.scale([0.2, 0.2]);
// And extrude. This creates a CSG solid:
var extruded=shape2d.extrude({
offset: [0.5, 0, 2], // direction for extrusion
twistangle: 180, // top surface is rotated 180 degrees
twiststeps: 100 // create 100 slices
});
</pre>
</body>
</html>