Plotting on the HP7475

Beard Generator

Below is a screen capture of the beard generator application I created in openFrameworks.  Parameters could be adjust to control the appearance of the beard, such as max length, max curliness, gravity, etc.

I drew some guide lines in Illustrator so I would know the general shape of the beard. Imported the lines into OF and made a grid of hairs and watched them wander, curl and grow.

One issue with the pen plotter is the lack of clipping. Which can be seen in the above gif. The lines eventually just form a dark mass of curlies. The plotter receives commands that construct lines and outlines, so I had to write some clipping code so that each hair would look more like a tendril. The output after clipping below.

Braid Generator

Now onto the braids. Instead of creating the braids entirely programmatically, I wanted finer control of their appearance. So I created three “braid pieces” in Illustrator. They are in green, pink and yellow. I designed them to be repeatable, nestling in nicely with their neighbors.

Each piece has four points of reference, as shown by the orange circles. They helped me determine the width and height of the braid and the offset of the lines to the center axis. I used the local x distance from the center axis to rotate the line points around a curve using the normal along the curve.

This position rotation is applied to every point in every line of each piece. The results of using many braid pieces along curved paths are depicted below.

I recently purchased a HP7475 Pen Plotter from ebay for about $110 with shipping. I love that this printer uses physical pens that are dragged on paper to make marks. The marks have the inconsistencies that arise when drawing with a pen on paper and they are beautiful.
The first step was talking with the printer from my MacBook. This printer was initially released in 1983. Several people have detailed steps about sending printer commands from a modern computer.
http://notes.variogr.am/post/29262500593/1980s-pen-plotters-of-the-future
http://grandahl.net/feed/?p=19
http://www.tobiastoft.com/posts/an-intro-to-pen-plotters
Chiplotle!

The printer uses a language called HPGL that is rather straight forward. The above links provide several different ways to communicate with the printer. I want to use OpenFrameworks to communicate with the printer and the above methods seem overly complicated to achieve this. Add-on time!
The original manual is online and there is a cheat sheet for some of the printer commands.
I wrote ofxHPGL to communicate with the printer and it’s rather straightforward. The serial buffer on the printer is super tiny, so there is a sleep millis in there so that the buffer doesn’t overflow. If the printer starts acting weird, that is usually the issue.

Step by Step video on how to add ofxSyphon addon to an empty OpenFrameworks project. View in full screen.

It’s hard to read the framework search path. It is: “$(SRCROOT)/../../../addons/ofxSyphon/libs/Syphon/lib/osx”

Always wanted to figure out shadows.
Simple approach in OpenFrameworks. Cleaned it up and put it in an addon.
ofxShadowSimple

Having some fun with soft bodies in ofxBullet

Connected Worlds is a large scale immersive, interactive ecosystem developed for the New York Hall of Science. Made while the Minister of Interactive Art at Design I/O. For a detailed description and a full list of credits, please visit the post on design-io.com.

Living Library is a large, interactive physical book with projected, animated content. Made while the Minister of Interactive Art at Design I/O. For a more detailed description and full list of credits, please visit the post on design-io.com.

An interactive visual experiment for the track Deserve by Bruzed. Live input mode allows the user to play any audio with limited visuals. Download the OSX application via the download link below.

Based on past experiences, I decided not to submit to the Mac App Store. You may have to change your preferences to use the application. System Preferences > Securty & Privacy > Allow Applications Downloaded from > Anywhere

Blair Neal has a great blog post about configuring an OSX computer to run an installation for ever. http://blairneal.com/blog/installation-up-4evr/.

I have been working on a ofxMacUtils addon with utils for making this process easier, so you don’t have to manually adjust the settings. It is still being developed, but thought it might be useful.

It has been tested on OSX 10.8 – 10.10 and OF v0.08. Any feedback would be appreciated ( through github, the comments on my blog don’t seem to be functioning properly).

InstaFigurator

A gui application for quickly configuring a mac for a long term installation.
Download the InstaFigurator.app

We like to use the energy saver schedule in the system preferences to set the computer to shut down and start up at specific times. Avoiding third party apps for this leads to a more universal understanding of how to set the schedule. Most system admins will know how to set the schedule via system preferences. However, one issue that I have run into recently (OSX 10.10) is this message.

The computer is either trying to restart or shutdown based on the schedule or manually selection and the OF app is preventing it from completing that task.

The addon includes an example for avoiding this issue.

Added some Anaglyph 3D rendering to BassShapes for some stereo 3D goodness. You need some red/cyan 3D glasses to view the effect. I released the OpenFrameworks addon called ofxCameraAnaglyph.