- Artistic Considerations - Mapping
Artistic Considerations in the use of the EyeCon Motion Tracking System
EyeCon allows a variety of movement parameters to be used as "input"
to the system:
- Position of body parts in space around you (i.e. the "touchline"
feature, or triggers in space)
- Dynamics (total body movement) within defined fields
- Position of the body on the stage area (using overhead camera)
- Height of body from the floor (using horizontal camera, and the "top"
- Width from left-most to right-most point on the body
- Degree of expansion or contraction
- Size of the body image (this is not quite the same as expansion-contraction.
the former is relative, the later absolute.)
- Degree of symmetry in the body (how much left resembles right)
- Number of dancers on stage (tracking feature)
- Relative closeness of dancers to each other
- Individual tracking and differentiation of dancers (based on costume color)
In terms of output, the sky's the limit. A few examples which
come to mind:
musical notes (synthesizer)
samples (*.wav files)
real time signal processing (using, for example, MAX/msp)
- Video Projection
film play forward-film play in reverse
real time signal processing (using, for example, NATO)
- Stage Lighting
- Mechanical Devices (mechanical hammers, wind, etc.)
Here then is a sample mapping:
Each choice of mapping (the arrows) may have two directions of
compliance /2/. That is, "more movement" may mean "more sound"
-- but it can also mean "less sound". This may sound counterintuitive,
but there are cases when it feels exactly right. For example, holding a shape
-- what we dancers call a suspension -- may require a lot of energy. So although
not moving, this moment might anyway be well represented by mapping "less
motion" to "more sound".
Must mapping be intuitive? Of course not. But in practice it won't
work very well otherwise. What we have found is that straying, even a little,
from what "makes sense" on a feeling level, results in an outsider
quickly looses the connection. It is harder than you think to follow these mappings,
any mappings, even when you've had them explained! Therefore, I would advise
to stay as intuitive as possible. "Boring" you say? No way! Believe
me, there is still ample room for experimentation and surprises in and around
this basic framework.
Indeed, as I look at the diagram above, it occurs to me that if
all those things were happening at once, no one would have any idea what was
going on! I actually can't think of a single situation when we used more than
two mapping at one time. In an entire piece, we rarely employ more than three
or four! We have made pieces with upwards of 250 Eyecon elements in them; this
is not what I am talking about. The number of mappings -- the kinds of the parameters
used -- are far more limited. Not because it would be technically difficult
to do so. It wouldn't. The reason is simply that one very quickly comes up against
the limits of what the inexperienced viewer can follow.
The arrows in the diagram above should also not be confused with
something like "tracks" in a composition. You might think, well, in
an orchestra you are not "aware" of what every individual instrument
is playing either, and yet the complexity can be marvelous. In the case of an
orchestra, however, there is at least mutual support! If you use too many mappings
they will likely fight one another, and the result will be that no single one
will be evident at all. In all likelihood, no single audience member will know
that anything interactive has occurred. But like I say: don't take my word for
it. Try it!
Making good mapping choices is really the "art" of using
Eyecon. There are no simple rules. Bizarre combinations of parameters have produced
stunning results. As I have emphasized already, sufficient clarity is the most
common problem. Ways to raise clarity include:
- repeat crucial movements a number of times.
- if you are a performer, move conscientiously. be aware of the affect you
are having on your environment and let this "inform" your movement.
- map to multiple outputs. for example, you may wish to link a sound element
with a particular movement as well as a visual element (a stage lighting change
or video projection element)
- think about camera angles. choose one which helps the movements to be accurate
- dancers tell choreographers or technicians what you need instead of the
other way around.
- "link" the media event to a particular gesture. the way a movement
is executed may be the key to an audiences perception of the event. try to
use memorable, movements -- those with character (even though technically
there may be no advantage to doing it that way)
- trigger or control the same events from the same stage positions or from
the same body posture even though, again, this may be irrelevant to the system
you are using.
- look for intuitive mappings (higher body level-to-higher pitch, faster-to-louder,
busier movement-to-busier sound, heavier movement-to-heavier sound, etc.)
- Near the beginning of the piece, or at least at some time during the piece,
use the system in a clear and transparent way. this way the system will "explain
itself" to the viewer. once having done this, they will become sensitized
to the "interactive experience" and will be naturally attuned to
And finally here's one that creates a stir:
- either before, or after the piece, explain to your audience how the technology
works. There are as many good reasons to do this as there are not to -- but
it is an option. To my thinking, it depends on the context (how formal the
setting is, for example) as well as the artistic demands of the piece involved.
Some pieces don't need it, some don't want it, and others simply love it.
Either way, whether you do it or not, I will guarantee you one thing: people
will come to you after the show and thank you from the bottom their hearts
for your decision, just as the person beside him castigates you for it!
Mappings may of course also be too simple. To lower the clarity,
- if you are using Touchlines (triggers), try to avoid hand or foot pokes.
Find ways to use your dancerly skills (there must be 50 ways to extend a body
- avoid using physically easy ways to execute an event. Make it harder for
yourself than it needs to be.
- choose dynamic rather than passive body positions (use plié, relévé,
spirals, etc. even when it is of no technical advantage).
- use more than one mapping in a piece (though not necessarily simultaneously!)
- think about the "direction" /2/ of the interactive relationship.
positive, negative; presence, absence. You may wish to reverse it.
EyeCon Help, this file last changed on 14. Feb.