StippleGen2 from our friends at Evil Mad Scientist Laboratories is a great little application for creating line art from graphic images. The docs on their wiki will give you a good overview of what it does.
When I first got my Egg-Bot I used an application called “Voronoi Stippler” to play around with stippling, but sadly the code for the application was taken offline. StippleGen2 takes the place of Voronoi Stippler quite well!
Original Hoan Bridge Graphic
I started out with this graphic of the Hoan Bridge, a Milwaukee Landmark, and converted the small color image to a larger grayscale image. (Why the Hoan Bridge? Because someone on Facebook suggested it!)
Here is the result of generating the TSP art. What is TSP you ask? Basically, it’s a path with a single line. It’s great for generating toolpaths used by things like CNC machines, engravers, routers, lasers, etc. (Find out more about TSP!)
I wasn’t convinced the TSP art would come out great, so I went to the circular stipples. Here’s the final version, which is incredibly hard to see rendered properly at this size, so look below for some zoomed in versions.
Stipple Artwork Zoomed In
Stipple Artwork Zoomed In More
Stipple Artwork Zoomed In Even More!
As you can see, the circles overlap, which means if we were to etch this with a laser, and use the vector setting (as opposed to raster) it would see each circle as a distinct object, and etch each one. (Etching as raster would most likely just etch it all as one single blob, no individual circles.)
So because each circle will be etched individually, and they overlap, we’ll end up with different heights/layers, as it were, due to some areas of our material being hit with the laser more than once. In other words… texture!
Here’s our final piece of laser-etched Baltic Birch plywood. Below you can see some zoomed in shots showing the surface. Notice how the circles are so small they essentially looks like dots. (You can click each photo to see the large version on Flickr.)