u/Banchals2

What kinds of environment(s)/pressure(s) lead to a species developing a written language that’s 3D. And not just scratches that can be observed with echolocation, but fully 3D structures that are free-floating. All of the main species in the series seem to have eyes and it’s just so strange to me that they, at some point, decided that floating 3D text was the way to go. Any ideas?
Thanks!