Here’s a demo from the University of Colorado, Center of Excellence, Advanced Technology, that shows ATAK projected onto a 3D sand-table for better command visualization.
It makes me wonder how you “3D print” a sand table. Let me know if you how they do that or whether to just 3D print it with ABS (more expensive, more durable).
Also, can you print a “thin” layer of 3D PLA? ( assume so, that would bring the cost down a lot. It would have to be made in sections though, unless you had a very large 3D printer.
Foam could also be cut and layered to match a topo map, cheaper then FDM and less messy then sand.