I am not really good with WE, but I tried many times to make a melee custom maps. Once I tried to make a custom race that use "sneak" and "stealth" tactics. I also tried to make buildings invisible.
I manage to do it, but with one building being "stealth generator" which would give all other buildings invisibility. Ability of that building was based on aura with custom triggers, coming into play once you research it.
Problem is, sometimes it will work, other times it wont, and sometimes it will cast invisibility on some buildings while others would remain normal.
It's not much of a help, but at least it might give some ideas for more experienced programmers.