Tuesday, July 6, 2010

SVG - The Universal Starting Point for Creating Cutter Files

Most cutter manufacturers have their own native file types for defining the files that can be used with their cutter.  But, there is one file type that has gained prominence as the universal portable standard.  Most of the recent versions of cutter software have the means to import an SVG file.

SGV stands for Scalable Vector Graphics.  Vector graphics use geometric objects such as lines, circles and curves to create an image.  The fact that objects are defined as formulas, rather than groups of pixels, allows us to recreate the objects at any size.  Hence, the Scalable part of the name.

In effect, when a cutter receives the data from a vector graphic it is told to begin at a certain language and make an arc or line of a certain radius or length and then turn so many degrees and move in another arc or line.  The degrees always remain the same.  But, the distance or radius of all the arcs and lines are increased or decreased by the same percentage relative to the original.

We can view a vector object as a path.  It's a bit like a child following a treasure map.  Suppose treasure was actually buried at the starting point of the map.  The map's directions might say:
  1. Turn West and take 5 steps
  2. Turn South and take 5 steps
  3. Turn East and take 5 steps
  4. Turn North and take 5 steps
Even if we altered the map to say go 20 steps after each turn, the child would still end up at the very same starting point.  And, that is true of the vector graphics our cutting machines use.  They simply follow the direction and distance commands sent to them based on the information in the vector graphic.

What many people don't know is that, unlike raster images, an SVG file is simply a special form of text file in an XML format.  XML uses descriptors and tags in a simple format to store data.  The great thing about this format is that we can actually go in and manually change the way a graphic behaves using a simple text editor like Notepad.

Rather than try to worry about specific cutter file types, we are going to concentrate on SVG files as our CREATE emphasis in this blog.  And, while there are several programs that can create SVG files, we're going to limit our tutorials to a free program called Inkscape so that anyone might be able to participate.

Craftwell has announced that eCraftShop Pro will be able to import SVG files.  And, since the target audience of this blog is those that want to create and cut their own designs. we're assuming that we'll need and want the pro version of the software.  I doubt that many of those following this blog will be content to simply work with prepackaged shapes.

So, while we wait for the eCraft machine to arrive, let's steep ourselves in the intricacies of Inkscape.


Cindy Cade said...

Tom, Converting SVG files to WPC Inkscape link
"0.45 version" can be found at: http://artisticextras.blogspot.com/2010/04/converting-svg-files-to-wpc-inkscape.html
Sorry, this is the only way I could reach you.

Tom Meeks said...

Hi Cindy,

Thanks for the link! All you have to do to reach me directly is to send an email is to use regmail at Tom Meeks (all one word) and that is a dot com. I'll check out the link right away.