Editing StippleGen
Warning: You are not logged in. Your IP address will be publicly visible if you make any edits. If you log in or create an account, your edits will be attributed to your username, along with other benefits.
The edit can be undone.
Please check the comparison below to verify that this is what you want to do, and then save the changes below to finish undoing the edit.
Latest revision | Your text | ||
Line 7: | Line 7: | ||
− | One of the perennial problems that we have come across in a variety of contexts, including [http://www.evilmadscientist.com/2012/cnc-halftones-with-ascii-art/ CNC artwork] and producing artwork for the [http:// | + | One of the perennial problems that we have come across in a variety of contexts, including [http://www.evilmadscientist.com/2012/cnc-halftones-with-ascii-art/ CNC artwork] and producing artwork for the [http://evilmadscience.com/productsmenu/tinykitlist/171-egg-bot Egg-Bot], is the difficulty of creating good-quality toolpaths– i.e., vector artwork representing halftones –when starting from image files. One of the finest solutions that we’ve ever come across is [http://mrl.nyu.edu/~ajsecord/stipples.html Adrian Secord's algorithm], which uses an iterative relaxation process to optimize a weighted [http://en.wikipedia.org/wiki/Voronoi_diagram Voronoi diagram], mathematically producing a set of points (stipples) that can closely approach the appearance of a traditional stipple drawing. |
Another important technique is [[TSP art]], where the image is represented by a single continuous path. You can generate a path like this by connecting all of the dots in a stipple diagram. Designing a route that visits each dot exactly once (and minimizing the distance travelled) is an example of the famous [http://en.wikipedia.org/wiki/Travelling_salesman_problem Travelling Salesman Problem] (or just “TSP”), and an optimal TSP path can give a surprisingly good grayscale representation of an image. From the standpoint of toolpaths (for the Egg-bot and most other CNC machines), a TSP path is even nicer than stipples, because little or no time is spent raising and lowering the tool. | Another important technique is [[TSP art]], where the image is represented by a single continuous path. You can generate a path like this by connecting all of the dots in a stipple diagram. Designing a route that visits each dot exactly once (and minimizing the distance travelled) is an example of the famous [http://en.wikipedia.org/wiki/Travelling_salesman_problem Travelling Salesman Problem] (or just “TSP”), and an optimal TSP path can give a surprisingly good grayscale representation of an image. From the standpoint of toolpaths (for the Egg-bot and most other CNC machines), a TSP path is even nicer than stipples, because little or no time is spent raising and lowering the tool. | ||
Line 15: | Line 15: | ||
StippleGen is easy-to-use software that can generate TSP and stipple drawings from input images. It saves its files as editable, Eggbot-ready Inkscape SVG files, which can in turn be opened by other vector graphics programs, or re-saved as PDF files for use in other contexts. It can also generate a TSP path from the stippled image, and either save that path as an SVG file or simply use that path as the order of plotting for the stipple diagram. | StippleGen is easy-to-use software that can generate TSP and stipple drawings from input images. It saves its files as editable, Eggbot-ready Inkscape SVG files, which can in turn be opened by other vector graphics programs, or re-saved as PDF files for use in other contexts. It can also generate a TSP path from the stippled image, and either save that path as an SVG file or simply use that path as the order of plotting for the stipple diagram. | ||
− | You can read an extended [http://www.evilmadscientist.com/article.php/stipple introduction to StippleGen] at Evil Mad Scientist Laboratories | + | You can read an extended [http://www.evilmadscientist.com/article.php/stipple introduction to StippleGen] at Evil Mad Scientist Laboratories. |
+ | == Download == | ||
− | == | + | StippleGen is free and open source software, written in the [http://processing.org/ Processing development environment]. It comes ready to run on Mac, Windows, and Linux, and it is [http://code.google.com/p/eggbotcode/downloads/list?can=2&q=stipplegen available for download here]. |
+ | |||
+ | (StippleGen is hosted as part of the Eggbot project [http://code.google.com/p/eggbotcode/ on Google Code].) | ||
− | |||
+ | The download includes ready-to-run platform-specific versions of StippleGen for Mac, Windows, and Linux, as well as the source code. You will need to have a recent version of [http://java.com/ Java] installed on your computer. If the platform-specific version of the software won't run on your computer, please install Java and try again.) | ||
− | |||
== Quick Start == | == Quick Start == | ||
Line 43: | Line 45: | ||
− | All of | + | All of Stipplegen's controls are accessed through the graphical user interface located in the lower part of the screen, in the gray bar. In what follows, we will go over the usage of the individual controls within the interface. |
Line 63: | Line 65: | ||
After the initial Voronoi diagram is calculated, StippleGen will display the stipple locations that it has calculated. This "first guess" is usually quite crude— as you can see above — and will improve dramatically as you allow StippleGen to run for a while. | After the initial Voronoi diagram is calculated, StippleGen will display the stipple locations that it has calculated. This "first guess" is usually quite crude— as you can see above — and will improve dramatically as you allow StippleGen to run for a while. | ||
− | ''Aside:'' The calculation of the stipple point locations through Secord's algorithm is an ''iterative'' process. For any given "generation," the process begins with an initial set of points— whether that's the initial set of "sprinkled' points, or the output from the previous generation. The Voronoi diagram of those points is then calculated, and each point is moved to the weighted centroid of its Voronoi cell. That distribution of points then serves as the starting point for the subsequent generation. | + | ''Aside:'' The calculation of the stipple point locations through Secord's algorithm is an ''iterative'' process. For any given "generation," the process begins with an initial set of points— whether that's the initial set of "sprinkled' points, or the output from the previous generation. The Voronoi diagram of those points is then calculated, and each point is moved to the weighted centroid of its Voronoi cell. That distribution of points then serves as the starting point for the subsequent generation.) |
Line 87: | Line 89: | ||
Two important notes about changing the number of stipples: Using larger numbers of stipples will increase the time required per generation. | Two important notes about changing the number of stipples: Using larger numbers of stipples will increase the time required per generation. | ||
− | And, again, please note that changing the number of stipples will restart the calculation from the beginning, as though you had just loaded a new file. | + | And, again, please note that changing the number of stipples will restart restart the calculation from the beginning, as though you had just loaded a new file. |
Line 101: | Line 103: | ||
However, the most important reason to pick one color scheme or the other may be the intended application of the resulting drawing. If, for example, you will be drawing with black ink on an egg, you will probably want to pick black stipples and a white background. On the other hand, if you will be [http://www.evilmadscientist.com/2012/cnc-halftones-with-ascii-art/ carving into a black panel], you may prefer white features on a black background. | However, the most important reason to pick one color scheme or the other may be the intended application of the resulting drawing. If, for example, you will be drawing with black ink on an egg, you will probably want to pick black stipples and a white background. On the other hand, if you will be [http://www.evilmadscientist.com/2012/cnc-halftones-with-ascii-art/ carving into a black panel], you may prefer white features on a black background. | ||
− | To toggle between the two color schemes, press the wide button underneath the stipple-count slider, labeled with the current color scheme (typically "BLACK STIPPLES, WHITE BACKGROUND"). Pressing this button will switch the color scheme and restart the calculation from the beginning, as though you had just loaded a new file | + | To toggle between the two color schemes, press the wide button underneath the stipple-count slider, labeled with the current color scheme (typically "BLACK STIPPLES, WHITE BACKGROUND"). Pressing this button will switch the color scheme and restart restart the calculation from the beginning, as though you had just loaded a new file. |
Line 108: | Line 110: | ||
http://evilmadscience.s3.amazonaws.com/wiki/eggbot/stipplegen/v2docs/plant2k.png | http://evilmadscience.s3.amazonaws.com/wiki/eggbot/stipplegen/v2docs/plant2k.png | ||
− | Shown above are two stipple drawings made from the same image of a corn plant, a sample image | + | Shown above are two stipple drawings made from the same image of a corn plant, a sample image that you can download [http://mrl.nyu.edu/~ajsecord/stipples.html here]. One drawing is made with black dots on a white background, and the other has white dots on a black background. However, each drawing has 2000 dots and the parameters are otherwise identical. In this case, as the source image was predominantly white, the image with the white background is of considerably higher quality, as the dots are concentrated in the area of interest, rather than in the background. |
Line 155: | Line 157: | ||
http://evilmadscience.s3.amazonaws.com/wiki/eggbot/stipplegen/v2docs/grace10k-dotrange4.png | http://evilmadscience.s3.amazonaws.com/wiki/eggbot/stipplegen/v2docs/grace10k-dotrange4.png | ||
− | In our demo image above, we have now adjusted the "White Cutoff" slider to | + | In our demo image above, we have now adjusted the "White Cutoff" slider to hide much of the background. |
− | + | Note 1: The "White Cutoff" slider will relabel itself "Black Cutoff" when working with white dots on a black background. | |
− | + | Note 2: While changing the white cutoff value will not affect the calculation of stipple locations, it does affect which stipples will be included in the output files. Because of this, changing the white cutoff will restart the calculation of the TSP path, if you change it while in "paused" mode. You can read more about the [[StippleGen#TSP_Path|paused mode]] below. | |
Line 187: | Line 189: | ||
− | ==== | + | ==== TSP Path ==== |
http://evilmadscience.s3.amazonaws.com/wiki/eggbot/stipplegen/v2docs/newgui-pausemode.png | http://evilmadscience.s3.amazonaws.com/wiki/eggbot/stipplegen/v2docs/newgui-pausemode.png | ||
− | When you press the "Pause" button, StippleGen ceases calculation of the stipple locations, and begins calculating the "TSP" path between the points. The | + | When you press the "Pause" button, StippleGen ceases calculation of the stipple locations, and begins calculating the "TSP" path between the points. The TSP ("travelling salesman problem") path is an efficient route plotted between the stipple locations. And, depending on how plan to use StippleGen's output, this part of the process may or may not be important to you. |
− | |||
+ | |||
+ | ''Note:'' If you press the Pause again (to unpause/resume calculation) the TSP path will be lost, and a new one will be calculated (from scratch) when you press the pause button again. | ||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | When you first press the "Pause" button, the path between the stipple locations looks like a rats nest. | ||
Line 213: | Line 222: | ||
http://evilmadscience.s3.amazonaws.com/wiki/eggbot/stipplegen/v2docs/newgui-loadsave.png | http://evilmadscience.s3.amazonaws.com/wiki/eggbot/stipplegen/v2docs/newgui-loadsave.png | ||
− | '''''Then''''' | + | '''''Then''''', press one of the two buttons to either save the stipple drawing or the TSP path. You will be prompted for the location to save the file. |
If you press one of the two save buttons before you have paused, StippleGen will not present you with a dialog box to save the file, but will instead go into the paused mode. If this happens, you can press the save button again, now that it's paused. | If you press one of the two save buttons before you have paused, StippleGen will not present you with a dialog box to save the file, but will instead go into the paused mode. If this happens, you can press the save button again, now that it's paused. | ||
Line 221: | Line 230: | ||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
==== Saving a Stipple Drawing ==== | ==== Saving a Stipple Drawing ==== | ||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
Line 303: | Line 239: | ||
==== Saving a TSP Path Drawing ==== | ==== Saving a TSP Path Drawing ==== | ||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
Line 345: | Line 262: | ||
== Source Code == | == Source Code == | ||
− | The StippleGen source code is available | + | The StippleGen source code is available as part of the [http://code.google.com/p/eggbotcode/downloads/list?can=2&q=stipplegen StippleGen .zip file]. To run the code from source, you'll need to download [http://processing.org/ Processing], and install the [http://hg.postspectacular.com/toxiclibs/downloads toxiclibs library] and the [http://www.sojamo.de/libraries/controlP5/ ControlP5 library]. |