The tactile pleasure of a sandbox is universal. A sandbox that displays dynamically updating contour lines and allows you to make it rain virtual water? That’s awesome. And when the water you’ve generated responds to the sand elevation levels according to realistic fluid dynamics, well then visitors are truly hooked.

In working with Habitheque, Inc. and the Fairmount Waterworks Interpretative Center to re-envision their watershed interpretation exhibit, we uncovered the research of a UC Davis team led by Oliver Kreylos on an Augmented Reality Sandbox. You might have read about their work in Wired magazine back in August of 2013. The sandbox requires an Xbox Kinect sensor, a projector, a CPU with 3D rendering, and open source code. Oh yeah, and many bags of sand...

How does it work? Using a ceiling-mounted standard projector, we project an image onto the surface of a common sandbox, filled with white sand. The Kinect 3D sensor, also mounted above, “reads” the surface of the sand, including depth, and projects a topographical map onto the sand surface in real time. So the map’s contour lines and elevation levels conform instantly to whatever configuration of sand you build. When you put your hand above the surface at “cloud level”, the Kinect sensor reads it as a cloud and makes it rain in that spot. This rain also conforms to the sand surface in real time, making it feel as if the water is actually on the sand, rushing down valleys and pooling at low points.

Beyond being tremendously fun and highly addictive, the sandbox achieves a number of key learning objectives. First off, it provides a fantastic demonstration of a natural environment, the relationship between ground elevations and rainfall, and exhibits the inherent properties of a watershed. It also provides a fantastic demonstration of real time fluid dynamics. What’s more, it acts as a bountiful hands-on platform for facilitated sessions focused on our complex relationship with watersheds, rainfall and flooding, and our rapidly changing environment. The most compelling aspect in many ways is that the highly tactile (not to mention mesmerizing) environment provides hands-on access to abstract concepts, activating kinesthetic learning.

We’re prototyping it at the Fairmount Waterworks for the next several weeks, if you’re in town and you’d like to check it out. And if you want help building your own, let us know. There are only a handful around the world right now, but we think that’s going to be changing soon.