Dasher

Script to convert Adobe Illustrator dashed strokes to actual paths.

Why this project?

Adobe Illustrator does not natively provide this functionality. We can "Outline Path" or "Expand Stroke", but there is no feature that provides simple open paths for each dash.

Example usages are cutting machines that require an open path to guide a tool bit or laser.

Installation

Download the script files. The scripts can be stored anywhere on your computer, but you must keep them all together in the same folder so that they can load each other.

Quick Start

To use it straight away, just make a selection in Illustrator and run Convert Dashed Strokes.js script.

This script will try to find any dashed strokes in the selection and create dashes path items on a new "Dashes" layer.

Remember: it won't work unless Bez.js and Dasher.js are in the same folder with the script.

Basic usage

Using convertToDashes method of Bez to convert one path item. No options are supplied, so it will use default options (see Configuration below).

    var item = app.activeDocument.selection[0];
    var bez = new Bez({ pathItem: item });
    bez.convertToDashes();

Configuration

The convertToDashes method of Bez takes an options argument. If it is not supplied, defaults will be used.

Example:

var options = {
    pattern: [8,2,4,2],
    alignDashes: true,
    strokeColor: app.activeDocument.swatches[5]
}

var item = app.activeDocument.selection[0];
var bez = new Bez({ pathItem: item });
bez.convertToDashes(options);

What is Dasher.js?

Dasher is a tool for generating and manipulating simple numerical patterns in the form used by Illustrator's stroke dashes.

What is Bez.js?

Bez is rudimentary class I used to store the bezier path handling functions required by this project, but I may develop it further in other directions if the need arises.

Please help with testing

As of 2022-01-25, this script is hardly tested at all, and only on my machine. Adobe Illlustrator 2022 (v26), MacOS 12.1.

Please post any issues you come across.

Known Limitations

In cases where the Illustrator path item is stroked with a strokeDashes array with an odd number of members greater than one Illustrator, at some path section lengths, seems to break it's own rules on how to fit the dashes. This looks to me like a bug, as it introduces strange lengths that don't seem to be logically derived from the strokeDashes. In these rare cases, Dasher makes a better-looking result, so I've not attempted to match Illustrator's behaviour.

System requirements

Adobe Illustrator CS6 and above. As of 2022-01-24, tested only on AI version 26 (MacOS 12.1).

Acknowledgements

Thanks so much to Hiroyuki Sato, for his bezier maths code from his excellent Divide (length).js script.

Project was inspired by a question asked by pixxxelshubser.