[dan_linder]

it's not the exact science museum experience mentioned, but a quick Google search for "sand table video augment" pulled up a few, and this was the first one I found: https://share.google/89A6x4yfaw5a4hOuh

When the first Xbox were getting long in the tooth, I believe people were repurposing the motion tracking bar as the mechanism to measure the topography of the sand table. That, coupled with a video projector mounted over the top of the sand table provides the additional colors and elevation lines. (And of course a bit of cool software to process and produce the image.)

[Waterluvian]

This is one of those things that's really not that hard, nor expensive, with one decent hacker who wants to set it up. Maybe $1500 of parts? Feels like the kind of donation lots of people here could make to a local lower budget kids science centre. And I bet would be the kind of donation these centres would love to have.

As a bonus: you can likely make it out of "100% recycled e-waste" and "100% recycled lumber" (if you're building the table, too), giving it an extra educational theme. not only is this cool, fun, and educational, but it's a demonstration of doing something good with a used depthsense, projector, and computer.