Lux Vocis is an interactive installation piece that draws laser portraits of a participant’s voice.  Check out this demo at the ITP 2009 Winter Show:

The machine utilizes two hacked hard drives, a method originally inspired by this hard-drive laser oscilloscope.  The drives are fed by a 30W stereo amp kit, into which is fed a stereo sound signal generated in Puredata.

Lux Vocis works like so: a user speaks into a microphone and my puredata patch picks out the most commonly recurring spectral peaks of the voice.  These frequencies are then used as seeds for a Lissajous figure, which is then drawn on the surface by oscillating the two mirrors attached to the hard drive voice coils.

Here’s another informative video:

And some selected drawings:

These proposals all incorporate a mechanical mark-making method (hah) as well as a

Proposal: This laser drawing machine uses an enclosed system of a low-powered green laser and voice-coil actuated mirrors to draw figures on a stationary or scrolling sheet of thermal fax paper, generating patterns of varying style and complexity. The patterns are generated algorithmically from the collapsed soundtracks of various experimental films.

I’ve begun developing an algorithmic, recursive gestural tree using JavaScript to draw into the HTML5 <canvas> element.  After running into a few initial problems, like discovering I was overflowing my browser stack limit, I progressed to some scribbly sketches.

Fixing the locating problems yielded these:

I then decided to move towards a continuous, single line composed of Bezier segments:

This could easily pave the way for a recursive sketching algorithm that composes each Bezier segment from n number of smaller Bezier segments down to a predefined number of levels.  The larger question, in this investigation, remains: what determines the high-level gestures?

The contour that a hand describes arcing through space is of a fundamentally different nature than the contour of a pencil’s mark, which is a remnant, but not from that of the hand that wielded the pencil.

Here we find the critical separation between the act and its imprint, between the cause and the effect.  Dance is a medium of causes that crucially leaves no mark except that of the phenomenological mark in the mind (brain) of the reader (observer).

When viewing a dance, under casual circumstances, we may not bother to attempt to fix in our imaginations the curvature that a body traces in the air, but rather leave it as a more holistic impression, an abstraction characterized by high-level features (degrees of activity, changes in energy-level, recognizable gestural signs, etc.).  The contours of a moving body supplement the contours of the body itself, extending it into another measurable dimension.  Visualizing these lines is not necessarily the goal, but rather building an awareness of them that shapes the perception of the entire dance.

Traditionally, and in general, dances do not leave marks in the sense that drawings do.  Dance does not visibly or permanently alter the intrinsic medium of its performance (spacetime).  A drawing does, however, transform a medium, additively or subtractively, with the aid of an extrinsic influence or medium (a pencil, a brush, an eraser, pigmented oil and water).  A dance’s extrinsic medium is the dancers that make it up, and its mark is like that of a poem read aloud—accomplished over time, with only the audience’s senses and memory available to contemplate the artwork.  A dance-poem leaves no residue upon its own medium.