In the game I'm making
http://developer.byond.com/hub/Kichimichi/neuroglia (shameless plug)
for interior spaces I'm finding myself wanting to make some turfs viewable from only some directions, since I'm using a top down view at an angle I want to be able to see walls that are above me but not below me, is that possible?, I'm thinking it would be a good var to implement into the game like noenterdirs noexitdirs and whatnot, anyhow just curios if anyone has any idea on this. otherwise I dunno I might just eliminate opacity, though that doesn't feel nearly as RP as I'd like it to be, though my outside tall buildings are impossible to work opacity into anyway.

Mike-