Use is designed to disappoint the viewer. The work is a challenge to our use of finite resources, exploring the joy of something beautiful and the tragedy when that beautiful thing is all used up.
Projected water flows through sandblasted acrylic channels, and as a viewer approaches, the water flows toward them. But suddenly, the water begins to drain. Eventually, it entirely disappears. The water will return only when the viewer leaves the piece.
To etch frosted channels into the acrylic, I used a vinyl cutter to create a mask (using a segment of the Mississippi River Delta as source image), and then sandblasted the surface. Only the gaps in the vinyl were frosted. The projection itself consists of two components:
1) An overhead Kinect and custom tracking program (Processing). The software looks for head-height blobs in the Kinect's depth image, and tracks each person frame-to-frame using the Hungarian Algorithm. Then, it uses the position of the acrylic sheet (calibrated beforehand) and calculates a relative position for each viewer. This is sent over OSC to...
2) A 2D water simulation, also in Processing. The acrylic sheet is broken into thousands of grid cells, and at each frame the water's position is re-calculated to flow towards the viewer. The simulation respects pressure, meaning that water can sometimes flow "uphill."
Thanks to OSC, the two computationally-intensive components can be run on completely separate machines, not to mention conveniently debugged with TouchOSC.