Eye-Balls: Cheap and Cheerful Interactive Performance

Most interactive performance systems to date have been expensive, large scale setups, targeted at genres where funding is typically available, such as modern dance and experimental music. With the Eye-Balls project, I attempt to create interactive performance which is accessible. This means minimizing both financial and technological requirements on the performer, and also choosing a style of performance which is accessible to a wide audience.

I chose juggling as a focus for this work. Juggling was a natural choice for multiple reasons. Firstly, I am a skilled juggler with performance experience, and wished to make something that I could perform with. Juggling is arguably inherently cheap and cheerful, characterized by the taking of simple and relatively cheap items and creating engaging performance through skillful manipulation of these objects. It is also a genre of performance characterized by individual artists and small groups, who are typically independent and self funded. Because of this, with one notable (expensive large scale) exception [1], juggling and other circus arts have mostly been ignored by developers of new performance technologies.

Fig. 1.

A simple Eye-Balls output. (©Joe Marshall)

Cheap

The Eye-Balls system uses a video camera, plugged into a computer, running software that visually tracks the position of a set of balls, and the head and hands of a performer who is juggling these balls. This information is then passed to a set of user written scripts, which create video projections and audio output based on the performer’s movements and juggling. A very simple example of an output is shown in Fig. 1. (Technical details of the tracking algorithms and scripts are available in [2,3]).

I designed Eye-Balls to only use commodity equipment, so that it could be used with a performer’s existing equipment. It requires a laptop computer, a video camera, and whatever output devices are being used, typically a video projector and a set of speakers. During development of the system, all performers I met during development including amateur groups, had access to a laptop and video camera suitable for running the system.

The laptop is placed in front of the performer, displaying what is output on the projection screen, so that they can get feedback and respond to the projections. Having this level of feedback allows the performer to create performances that respond to their juggling, allowing improvisation and flexibility in timing. This is in contrast to current ways of accompanying performance such as prerecorded soundtracks and visuals, which are typically non-responsive and fixed in time, so require the performer to react to them. This in turn limits the possibilities for interaction with the audience at points when the music is on or the visuals are playing. In Eye-Balls there is freedom to improvise, with the ability to work with other audio/visual elements. Eye-Balls has been used for several performances, including public cabaret, academic conferences, small group demonstrations and digital art events. Audience sizes have been anything from 20 people up to a large theatre with 500 people. A recent performance I have worked on is entitled “Juggling Like a Bicycle”. This was designed as an attempt to move away from an abstract computer-generated style of performance and explore the use of the system in a more classical comedy juggling performance. The next section presents an illustrated script, as an example of a performance in Eye-Balls (all pictures ©Joe Marshall).

Cheerful

Hi, my name’s Joe and I’m a juggler.

I move a ball in the shape of the word “Joe”, which causes it to be written on the screen above me. Ooh isn’t that clever! I jump into a victory pose (shown below), arms raised, and the screen changes to a picture of a bike.

I have a dream... No not that one. This is more odd (at this point I talk all about my bike and how much I love it)

Anyway, I had a dream about my bicycle and...