DorkMatter.net

I spent a couple of hours working on a graphic of a dandelion the other weekend and I thought I would share how it was done.

The design is simple. Using Inkscape, I began by drawing the dandelion stalk using the Freehand Tool (using spiro for that nice curve) and coloured it with a slight gradient from pale green to dark green.

For the head I simply drew a circle and filled large number of very small star-shaped hand-drawn polygons. Drawing these by hand meant I was able to ensure a good placement. Initially I had drawn a series of star shapes and tried using tile clones to place them radially. This created a very geometric look so I decided to hand-draw for a more organic feel.

After filling the circle with stars a few were dragged across the canvas to create the “just blown” look. I then made the guide circle completely transparent. Leaving it there meant I could still check the placement of the stars by viewing the image in Outline Mode (View>Display Mode>Outline).

The star shapes were selected (Edit>Select All and while holding Shift, click on the stalk to deselect) and in the Fill & Stroke Dialogue I set the blur to around 3. The stars were copied and pasted in place and while the duplicate stars were still selected I set the blur back down to zero. This makes a sharp star shape with a blurred halo, creating a soft appearance without losing detail.

And that’s pretty much all there is to it. Opinions welcomed.

Now you have your development version of Inkscape running, let’s have a look at the Spiro option. Select the Freehand (Pencil) Tool. You’ll notice an addition to the toolbar:
Make sure the “Create Spiro Path” mode is selected as shown. This will correct your freehand lines to smooth curves which you can adjust using the Smoothing Slider. Currently this can only be set before drawing your line so some experimentation will probably be required to get the amount of smoothing right.
This image shows you how it works. The blue path shows the line I drew. The purple line shows the path with Spiro applied.

As with any path, you can edit each node and the Spiro path will adjust accordingly.

Shape

Spiro paths can be shaped. This shows each type of path; None, Triangle In, Triangle Out, Ellipse, From Clipboard.

None: This draws a simple line with no shaping which you can thicken or thin using the Stroke Style dialogue. There you can choose the cap or even add markers to your line. Change the colour using the Stroke Colour dialogue.

Triangle In & Triangle out: The line is thickened at one end. By default you can change its colour using the Fill Dialogue but you can also apply a stroke colour. If you do so the stroke is an outline of the triangle shape so thickening it will eventually cover over the fill colour rather than increase the size of the whole object.

From Clipboard: Use an existing path to shape your spiro path. In the example above I used a star shape and applied it to a curved line to create the deformed star shape. You must use a path for this trick to work. If you draw a shape you’ll need to convert it to a path first Path>Object to Path. The colour of your original shape will not be preserved.

How can you thicken a shaped Spiro path?
Try resizing a shaped Spiro path and you’ll soon see that proportionately remains the same, but what if you want a much thicker object than the one you drew? If you thicken the stroke you’ll find the lines are blunted and the fill colour becomes occluded by the stroke. The secret is to draw small and scale up. Here’s an example.

The two paths on the left show how scaling a medium sized path up slightly thickens the overall object.  The two paths on the right show how drawing a very small path allows much more noticeable thickening when the image is scaled up.

Notice how the stroke has scaled with the image? If you don’t like this effect you can decrease the stroke thickness through the Stroke Style Dialogue.

This is quite a dirty workaround to the problem and hopefully a better  solution will be incorporated into the final release.

When I first read about the new spiro feature on Andy Fitzsimon’s blog I thought it was so cool I had to have a go.

Spiro is a new feature in development for Inkscape which is an add-on to the Freehand Tool. It modifies your stroke path into spirals giving a very fluid look to curves and lines. Spiro isn’t the only new tool for the next version of Inkscape. There are new filter effects to play with so it really is well worth the hassle of trying development version.

Check out the download page for the most recent builds for your operating system. You’re likely to find the development version pretty unstable so don’t go deleting your copy of 0.46 just yet.

I use OS X 10.4 which currently has no up-to-date downloads available so I’ve had to compile it myself. If you’re in the same position, it’s not as hard as it looks. Read Inkscape’s page on compiling Inkscape on OS X. Make sure you have XTools installed (searching for it in finder will be enough). On my copy of 10.4 it was already installed. If it isn’t, you’ll find it on your installation CD.

I’m going to show you how to download and install this using MacPorts. If you want to use MacPorts for the download instead of installing everything manually, you’ll need a newer version of XTools. I found the correct version on Download.com as it’s no longer available on the Apple Developer Network for 10.4.

For this installation you’ll be using the program Terminal to work from the command line.

Tip: If you’re using the packaged version and get “command not found” when you try running the port command, see this work around. If you already have a .bash file, open it (nano .profile), copy the line inserted by macports and paste it into your .bash_profile and it should now work.

Assuming you got MacPorts up and running, copy and paste this into Terminal. Expect it to take a long time to run. You’ll be required to enter your system password.

sudo port install cairo +pdf boehmgc gtkmm intltool libxslt lcms popt poppler boost gnome-vfs \ libgnomeprintui automake autoconf subversion

Finally, to complete it, run this command:

svn co https://inkscape.svn.sourceforge.net/svnroot/inkscape/inkscape/trunk inkscape cd inkscape/packaging/macosx/./osx-build.sh a c b i -s p

Navigate to your new Inkscape directory and into the folder packaging/macosx/ and open the file named Inkscape to run it.

Next: Using Spiro paths.

Since my last post I had a hard drive failure and lost all my work since July, including the two drawings I posted recently. So, I decided to redraw the dandelion image.

Last time I used tile clones but looking back on it the positioning of the fluff was far too geometric, so I got rid of the tile clones idea and redrew each seed instead of generating them. I think this looks more natural.

Not quite sure what to do with the stalk yet.