passerby - I have them on planes. trancerbot - this is supposed to be an older school. I'm using reference from an abandoned school damaged by a fire. Here you can see the ceiling is indeed made up of tiled attached to a concrete ceiling. More modern schools use the drop ceilings you mentioned.
I'm not part of the study group, but I'd like to mention that your ceiling is very odd for a classroom. It looks like tiles glued onto a very low concrete slab, which is very weird - I've never seen any class like that, and it leads me to wonder where the light fixtures would go (update: well I suppose they'd work like…
I'm willing to change to a drop ceiling later. I did a quick test of what that might look like (i.e raising the concrete slap out of sight) and it looked good. For now though I'm going to just keep working on more stuff that isn't done yet. A lot of adjustment needs to be done after all the assets are created to make this…