What I'd like is for the player to be able to "click" (like an activator) in the empty spot and choose to replace the missing piece, but can I do that?
Other ideas are good too. I thought maybe a button or something, but that doesn't make sense insofar as placing something goes. Also, there are no meshes near enough to the empty spot to use as activators without it being obvious that it's the object and not the empty space the player is activating...