Traffic activity driven generative laser projection.

Generative laser projection mapped onto roundabout in Santiago de Chile. The drawings were generated by tracking the flow of cars using a custom made computer vision system. This urban light intervention was part of the KuzeFest Lights Festival of Santiago 2017. This work was presented at the festival’s closing party that took place at Galeria Cima art gallery, that overviewed this roundabout.

This project used a laser projector, which has a powerful laser bounced of 2 mirrors that oscillate very fast, thus moving the laser beam, which create the illusion of a line whereas its just a point. I chose to use this kind of projector for two reasons:

  • Because of the nature of laser light, this projectors can shoot from long distances without becoming dimmer as regular video projectors do, and span over really large areas allowing to deploy quite large graphics making these ideal for this project.
  • The laser ray, according to the hollywood-esque code, works simultaneously for delimiting space and an intruder detection system, as part of a larger surveillance system, which closely relates to the other aspects of this work, discussed further down.

I developed openFrameworks application to control the laser beam and track the cars. The video feed from a USB camera that was overlooking the whole roundabout was used to track the cars lights. The drawing was generated based on all the tracked points, which was then sent to the laser projector through a special interfase.

Several artifacts were generated due to how this kind of laser projectors works. The complexity of what is being drawn is limited by the oscillations of the mirrors. When more complex shapes are drawn the “refresh rate” or “scan line” becomes visible. Forcing the projector to draw sharp corners limits this even further; the projector interpreted corners as smooth curves, naturally interpolating the sides of the corner. As I ended liking this artifacts, which produced more “natural” shapes and introduced a lot of uncertainty, I decided to keep these. I think of these as the projector’s “contribution” to the project.

When I got invited to this lights festival I was told to make something at its closing show. It was going to happen on a terrace on the top of a building overlooking Plaza Baquedano (commonly mislabeled as Plaza Italia), which is located in the main avenue/axis of the city and it is usually referred as the point that divides the city between upper and lower social classes. This two aspects of the location are the pivots of this work.

Even when in most major cities surveillance systems are ubiquitous, from small household CCTV networks to city wide traffic control systems, people usually don’t care or don’t even know about these. The interaction with these systems is usually both unwillingly and unconsciously. In a lot of cases this interaction is anonymous; the individuals identity doesn’t matter, it is its behaviour within the mass and the mass’ behavior that matters, from which data can be extracted. This data is most of the times restricted to very few and privileged people. In a similar way, the data that I extracted from the cars/people passing through this roundabout was presented to the audience at this event, the few privileged ones that were able to see it from above as it was not visible from street level. By presenting this data in a very pleasing, even hypnotizing aesthetic form this work tries -hopefully without success- to mask the social threshold that this city location represents.

Aereal videography by Gonzalo Zuñiga

Laser Projector provided by Raul Zamorano.

Made with openFrameworks