software sample from palindrome

Robert Wechsler (
Tue, 3 Mar 1998 16:27:27 +0100

hi group,

it occurs to me, some of you (with access to a PC running Windows95) may
wish to play around with a copy of our software ("Touchlines" and "CRAT").
in return we would just ask for your comments and suggestions.

At the end of this letter, I will attach a description of what it does.
There is a (new) longer paper on the subject available as well. Let's see,
I'll make it available at D&TZ. (give me a day or so). or write me.

It is, by the way, unlikely that you will actually be able to generate
interactions with the software we are now offering. That is, you will
probably not be able hook up a video camers or vcr. There are some few
technical reasons why we are not doing this yet. For one thing, you need a
good frame-grabber and special drivers. If you do become interested in
getting it running with a camera, just let us know.

In the mean time you can use it to trigger media events (for example, if you
have a sound board, you can generate sounds, etc.) by using a
simulation-dancer, a thing built into the program for this purpose. Even if
you dont have a sound board, you may find it interesting just to give you a
feel for it.

Our video tape (also available) demonstrates some of its uses.

Apropos, the video, I am happy there has been so much interest (i have sent
out 15 copies). There is now a newer version (I have attached new material
onto the older version). We very much appreciate your comments -- and those
of your students. it is not, i repeat, a high-quality video, but you do see
what we are up to.

For the software, just e-mail me where to send it (as ".zip" file), or an
address where i can send a disk. I will include some instructions.

For the video tape, send me a check for 30 US dollars, indicate NTSC or PAL,
and of course your address. (this money, at the current exchange rate,
covers postage and copying). Please do not send deutschmarks.

Robert Wechsler

..... The second type of technology we use is based on "frame-grabbing", or
the capturing of video images in the computer's memory. By frame-grabbing a
dancer's movements and processing them with software, it is possible to
essentially convert their dancing to other media (for example, music or
screen projections). Video cameras are set up around the stage; one above,
and two at the down-stage corners. Together, they give the computer a
3-dimen-sional view of the dancing.

Palindrome has developed two software for use with this system. The first is
called Touchlines. With it, one can draw lines onto frame--grabbed video
images (see Figure 1). These lines are sensitive to change. That is, if the
image behind one of these on-screen lines changes (for example, by the
movement of a dancer's hand) sampled sounds, musical notes, lighting
changes, projections or other media events can be triggered. Touchlines are
programmable in many ways. One line may be triggered with the tiniest of
finger movements, while another may require the dancer to run the entire
length of the stage to play all of its notes. Additionally, some touch-lines
can be used to control others, adding new lines and deleting old ones as
they are called for in the course of a dance.

"Minotaur" is our most sophisticated use of this system to date. It involves
four dancers playing a composed musical score entirely by their move-ments
in space. Coordinated through a series of scenes within the computer, over
250 touchlines are used in the six minute dance. In Minotaur the distinction
between dancer and musician is rendered meaningless.

The second program we use is called CRAT (color recognition and tracking).
It is similar in principle to touchlines, except that now the computer
follows each dancer separately by locking-on to the color of their costume.
As with touchlines, CRAT can be used to control various media, but with some
important differ-ences: First of all, since they are distinguished by
costume color, each dancer can have an indivi-dual effect. In the piece
S.E.T.I., the dan-cer's movements are graphically represented on a projected
screen. Each paints with a different color, leaving behind a visual history
of where the dance has been.

CRAT also has the advantage of allowing not only the absolute positions of
the dancers, but also their relative positions to be used as parameters.
Thus, speed or other movement qualities may be used as determining factors.
Finally, an effect which Palindrome uses in a number of dances ; the
distance between the dancers can be used, for example, to control the music.

Our piece AbstŠnde (which in German means "distances between") uses this
program in an interesting experiment. Everyone knows the psychological
impor-tance of keeping the correct distance between ourselves and others. In
our dance, we've divided these "abstŠnde" into three types: man-to-man,
woman-to-woman, and man-to-woman. Three channels of music are controlled by
these three "gender-abstŠnde". This means, for example, when the women
dancers move closer together in the dance, the music shifts to its special
"woman-with-woman" sound, and so on.

Robert Wechsler and Helena Zwiauer Phone: (49) 911-397472
Palindrome Dance Company Fax: (49) 911-397472
Johannisstr. 42 / 90419 Nźrnberg