Artist Lorenka Stropnik contacted me to create an interactive projection for her. Videomaker Luka Dekleva provided the videos, i would take care of the animation/particle system and detection of people, as the projection should move around them.
The project involved a huuuge projection across the ljubljanica river in Ljubljana. The 30m distance proved quite challenging for sensors i would regularly use (kinect/ir cam), so we opted for a surveillance camera with built in leds with supposed 40m range.
The camera we chose ended up being a hybrid sensor, meaning that they did not block visible light, neither the IR wavelength. So this was kind of a problem for us, because we did not want to see the projection, just the people.
We solved this with a floppy disc:) Yes this actually works, attenuating the visible spectrum but still letting the IR light through.