> Motivation
> Example Movie
> Comment
> Conclusion
> Related Experiments
> Setup


Performance Photo

Screenshot

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Motivation

How can one visualize the virtual space a dancer has passed through? Mathematically the three dimensional space can be defined by the Cartesian coordinate system with its three orthogonal axes. An axis is typically represented by a vector or a line. Given a grid of lines in space, we can visually determine the location of an object by relating it to a cell within this grid. The axes are serving as metering rules, which are spanning the space. If we let the dancer leave such metering rules in space while he passes through, we might have a legible definition of the space he once occupied.

This experiment derived out of reducing the visual elements to just a ball representing the sensor and the poles as building blocks of a construction.

 

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Example Movie

Stage View
Computer Image
The movement of the sensor (attached to the dancer's left hand and represented by the small red ball) establishes gray beams that pop up as vectors according to the direction and angle of the sensors' motion: either vertical or horizontal, or from front to back. The space with the gray beams is slowly turning which makes it easier to read the 3-dimensionality. In the second half of the experiment the spatial continuity is broken and the beams appear in a shifted and broken-up space.

 

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Comment

Dancing is usually a very transitory activity: you move through a sequence or improvise for some time, but afterwards there is nothing left to hold in your hands, nothing that you made that can be left in the space where you danced. In this experiment the dancer is building while dancing: more and more vectors appear and are put into a structure that forms a body of pure directions and vectors of his dance. And at the same time one cannot ignore the image of the growing structure filling up the virtual space, as if the dancer is building up this structure around him, which takes away the space he needs to move.

In a very short time the dancer has built up a dense grid of poles and as he interacts with them the grid grows ever denser. Sometimes they are encountered as obstructions to be avoided and danced around and at other times as tools to help the dancer accomplish some task. A certain spatial environment makes us learn how to move inside it very efficiently until it becomes second nature. In the video-excerpt of this experiment there could be an even clearer moving with and through the structure of the vectors.

Because of the dependence the dancer has on the screen-image to help him form his improvisational material, a strong relationship is built up between the dancer and his projected movement-representation.

 

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Conclusion

In comparison to the definition of the space is more coherent and concrete. But on the other hand - because of the increasing quantitative dominance of the already placed poles - the space becomes successively more and more static. With a certain complexity a new pole is becoming more integrated into the current construction rather than changing it. Due to the extend of the poles, spanning a large region in space, the construction quickly fills up the whole space. Reducing the pole length or linking it to motion properties, e.g. the speed of motion, might overcome this problem, resulting in a more local impact.

Because the pole's direction is aligned to the dominant axis of the sensor's motion vector, the pole direction is sometimes difficult to correlate to the sensor motion. With small motions this is due to the jittering of the data, which could be enhanced by filtering the data over time. But even with faster motions the orientation looks reasonable only if the motion extends a certain time before and after the placing of a pole. An adaptive measuring, which keeps the continuity of a motion into account would be better than measuring at regular intervals in time.

 

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Related Experiments:

 

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Setup

 

Hardware:

  • Graphics PC
  • Projector
  • Polhemus tracking system: 1 Sensor
  • RF Button

 

Configuration:

  • The Sensor is attached to the dancer's left hand. The position of the sensor is controlling the position of a red ball. When moved, the ball leaves a trace in the form of a red line. In regular time intervals Gray Poles are placed at the current position of the sensor. The poles' orientations are aligned to the 3 space axes according to the closest direction of the current sensor movement. The Technical Screenshot below shows the sensor as a green wireframe sphere.
  • The Virtual Space is cut into 12 slices. Each slice has a defined extension within which a part of the virtual space is displayed. The slices can move arbitrarily in space. In this setup the slices are rotated and shifted slightly amongst each other. The adjacent part of the virtual space is transformed with the slices' transformation. The Technical Screenshot below shows the slices as white outlined cubes.

 


Technical Setup

Spatial Setup

Technical Screenshot

Screenshot
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