---
title: Intersection
---

<p>
    You can find the point(s) of intersection between two paths using <a href="/docs/api/modules/makerjs.path.html#intersection">makerjs.path.intersection</a>.
    If the paths do not intersect, this function will return null. Otherwise, it will return an <a href="/docs/api/interfaces/makerjs.ipathintersection.html#content">object with a property named intersectionPoints</a> which is an array of points.
    Additionally, if either path was an arc or circle, this object will contain the angles at which an intersection occurred.
</p>

<p>
    Intersection examples:
</p>

{% highlight javascript %}
//line-line intersection

var makerjs = require('makerjs');

var model = {
    paths: {
        line1: new makerjs.paths.Line([0, 0], [20, 10]),
        line2: new makerjs.paths.Line([2, 10], [50, 2])
    }
};

var int = makerjs.path.intersection(model.paths.line1, model.paths.line2);

if (int) {
    var p = int.intersectionPoints[0];
    var id = JSON.stringify(makerjs.point.rounded(p, 0.01));
    model.paths[id] = new makerjs.paths.Circle(p, 1);
}

var svg = makerjs.exporter.toSVG(model);

document.write(svg);
{% endhighlight %}

<script>
    LiveDoc.evalLastCode();
</script>

{% highlight javascript %}
//circle-circle intersection

var makerjs = require('makerjs');

var model = {
    paths: {
        circle1: new makerjs.paths.Circle([0, 10], 20),
        circle2: new makerjs.paths.Circle([20, 0], 20)
    }
};

var int = makerjs.path.intersection(model.paths.circle1, model.paths.circle2);

if (int) {
    int.intersectionPoints.forEach(
        function(p, i) {
            var id = JSON.stringify(makerjs.point.rounded(p, 0.01)) + ' intersects circle1 at ' + makerjs.round(int.path1Angles[i], .01) + ' circle2 at ' + makerjs.round(int.path2Angles[i], .01);
            model.paths[id] = new makerjs.paths.Circle(p, 1);
        }
    );
}

var svg = makerjs.exporter.toSVG(model);

document.write(svg);
{% endhighlight %}

<script>
    LiveDoc.evalLastCode();
</script>

{% highlight javascript %}
//line-arc intersection

var makerjs = require('makerjs');

var model = {
    paths: {
        line1: new makerjs.paths.Line([0, 0], [20, 10]),
        arc1: new makerjs.paths.Arc([12, 0], 10, 45,215)
    }
};

var int = makerjs.path.intersection(model.paths.line1, model.paths.arc1);

if (int) {
    int.intersectionPoints.forEach(
        function(p, i) {
            var id = JSON.stringify(makerjs.point.rounded(p, 0.01)) + ' arc1 at ' + makerjs.round(int.path2Angles[i], .01);
            model.paths[id] = new makerjs.paths.Circle(p, 1);
        }
    );
}

var svg = makerjs.exporter.toSVG(model);

document.write(svg);
{% endhighlight %}

<script>
    LiveDoc.evalLastCode();
</script>