“Quartz Composer is a node-based visual programming language provided (for free) as part of the Xcode development environment in Mac OS X for processing and rendering graphical data.” – Wikipedia

Quartz is pretty fun to make moving, interactive graphics. As seen elsewhere on this website, I’ve done a number of art projects and tutorials focusing, in particular, on audio visualizations that take their primary input from a webcam.  You can download some of my compositions for free below. A couple of hints / tips follow the listing at the bottom. (Click on Composition Titles to Download.)

Audio / Music Visualization based on Webcam Source

  1. Three Panel Hacker Dream splits the screen into three distinct sections that respond, left to right, to low, medium, high frequencies of sound/music.  They are a multi-level combination of R,G,B color schemes, enhanced video,  and ASCII-art video on top of each other. Good for a wide range of music.
  2. Sequential ScatterGrid is a 20×20 grid of boxes that react to the volume peak and sound/music frequencies in sequence (from top left to bottom right).  Designed particularly for high energy music, this composition is incredibly hyptonic. You’ll get lost in it.
  3. Ghostly Recursion is the most elegant and “pretty” of the visualizations. It definitely needs full-spectrum frequency representation, but it can be very responsive and looks gorgeous. Probably the best of these visualizations for slower songs, too.
  4. WAVIQ is the first of these types of visualizers I put together – it was also my first Quartz Composer experiment. It was displayed by a projector at Artomatic as part of a larger installation at Artomatic here in DC for five weeks.  This is the same composition as has been downloadable on this website for some time.

Quartz Composer Custom Utility Patches

  1. A Mac OS X Distributed Objects server for the Neurosky brain wave reading Mindset and a Quartz Composer plug-in client for the server.
  2. Timer Patch composition contains a timing patch that, by default returns “false”, but will wait for a certain amount of time and return “true”. You can specify how long the “false” time is and how long the “true” time is. You can also specify how long after you start your composition the patch waits before beginning its loop.
  3. Movement Detector Patch composition contains a patch that detects movement in a video stream (webcam). It does  does by splitting the stream into a grid of 25 sections. For each section, it averages the RGB color values then averages the color change for each section. If there is a lot of movement, a lot of the areas should high values of color change, and the patch will return TRUE. You can set the minimum amount of change needed for the patch to return TRUE. It also has an output for the amount of change if you want more of a scale than YES/NO.

Hints

  • To use the Custom Utility patches, just open the composition and copy/paste the macro patch into your own composition. I didnt do anything special to package the patches. I might do that in the future.
  • For the audio stuff, some of the compositions may be set to “Line-In” for source, others “Built in Mic”.  You can change that by diving into the composition and finding the “Audio Input” patch. Remember that that might be buried in a series of other macro patches, so you might have to click through a couple of layers to find it.  Once you find it, highlight it and click the patch inspector. Under settings, you should be able to choose the Audio source you prefer. Also, your OS’s input volume settings (sensitivity) will affect these compositions – so go into “Sound” in OS X’s System Preferences and fiddle with that if you think it will help.