marey/langer/chaos/robotics

Scott deLahunta (sdela@ahk.nl)
Wed, 15 Sep 1999 13:55:51 +0200

Dear List --

I am always interested in the past -- and here are a set of random
observations:

1)
Before her time?

In 1957 Susanne Langer published 10 of her lectures in a book entitled
*Problems with Art*. Her first lecture is "The dynamic image: some
philosophical reflections on dance". The following paragraph struck me as
rather rhetorically contemporary.

"What dancers create is a dance; and a dance is an apparition of active
powers, a dynamic image. Everything a dancer actually does serves to
create what we really see; but what we really see is a virtual entity. The
physical realities are given: place, gravity, body, muscular strength,
muscular control, and secondary assets such as like, sound, or things
(usable objects, so-called "properties"). All these are actual. But in a
dance, they disappear; the more perfect a dance, the less we see its
actualities. What we see, here, and feel other virtual realities, the
moving forces of the dance, the apparent centers of power and their
emanations, their conflicts and resolutions, lift and decline, there
rhythmic life. These are the elements of the created apparition, and are
themselves not physically given, but artistically created."

2)
The Earliest Motion Capture?

The late 19th century inventor, Etienne-Jules Marey, created a mechanical
apparatus in order to register the trajectory of the wing of a bird in free
flight -- and this device registers the up and down and back and forth
movements of the wings simultaneously. It "could transmit to a distance any
movement whatever and register it on a plane surface". Marey made various
instruments to study motion as did others of that time -- making measuring
devices which attached to the body at one end and left a mark at the other.
(see Marta Braun's *Picturing Time: the work of Etienne-Jules Marey
(1830-1904)*. London: U. of Chicago Press, 1992.)

3)
Software has a history too.

In a recent presentation here in Amsterdam I had the good fortune to have a
videotape documentation from Liz Bradley's Chaographer project. If you're
interested in reading more you can visit their site at
http://www.cs.colorado.edu/~lizb/chaotic-dance.html. Liz and her partners
have created a program which can generate chaotic variations on a movement
phrase created in Lifeforms. In doing so they are drawing on a history of
software development/engineering which includes Edward Lorenz's chaotic
generation equations created in the '60s when Lorenz was simulating weather
patterns on a computer system. Lorenz was the discoverer of the by now
familiar "butterfly effect". Another bit of software material used by
Bradley et al. is Dijkstra's algorithm created in 1959. This is an
interpolation algorithm for determining the "shortest paths from each
vertex to all other vertices in a weighted, directed graph".

Most dancers/ dancemakers interested in new technologies are using/
experimenting with end-user software -- which really include bits and
pieces of software possibly written over the last few decades, written by
different individuals for different programs. I am of the opinion, that if
we are to get the most out of an overlap with technologies -- then we
should engage in a knowledge exchange on a level of software. This is not
to say that dancers should become programmers just as programmers should
not become dancers necessarily, but become more effective collaborators we
should learn more about the underlying processes of each field.

4)
More Software history...

Michael Girard and Susan Amkraut are masters in the field of character
animation. Amongst other achievements, they were key collaborators in the
creation of 'Hand Drawn Spaces', the virtual dance by Merce Cunningham and
Riverbed, for which they developed some sophisticated software to work as
part of the animation program 3-D Studio Max. Referred to as 'footpaths'
and the 'motion flow editor', these softwares tools were used to organise
and blend selected movement sequences together. Footpaths and Motion Flow
are imbued with a sort of intelligence about how the human body actually
functions... where did these algorithms come from??

On Riverbed's site (http://www.riverbed.com) you can read a conversation
between Michael, Susan and Paul Kaiser which traces the history of their
investigations into computer graphics and figure animation. At one point in
their development as animation artists they became less concerned with what
their animations looked like and more concerned with how they operated --
what the physical forces behind the movements were. At that time, Marc
Raibert, founder of MIT's LegLab http://www.ai.mit.edu/projects/leglab/,
was at Ohio State University studying running and walking in order to make
robots move -- and Michael and Susan discovered that some of the same
algorithms used for making robots walk and run could also be used in
computer animation.

***********************************

Regards,

Scott

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Scott deLahunta and Susan Rethorst
Writing Research Associates, NL
Sarphatipark 26-3, 1072 PB Amsterdam, NL
mobile: +44 (0)797 741 2060
tel: +31 (0)20 662 1736 / fax: +31 (0)20 470 1558
email: sdela@ahk.nl

w1: Writing Research Associates
http://huizen.dds.nl/~sdela/wra
w2: Dance and Technology Zone
http://www.art.net/~dtz
w3: Digital Theatre: an Experimentarium
http://www.daimi.au.dk/~sdela/dte

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