Code: All thru this forum and the old GPG threads. Ask around if ya need help find the older posts.
Melee: Possible in a very basic sense. GPG tried it and left the functions in but i doubt you'll be able to do much that "looks" realistic.
Invisible units: Very easy to do if your just not wanting the unit(s) to be visible for an opposing faction. (aka dummy units or placeholder units) However true stealth in FA & FAF is bugged to the engine. Basicly stealth / cloaking works like what you'd initially expect but then things get weird once a unit has been detected. Example: Your stealth bomber is cloaked / radar invisible and moves in on a target to drop a few bombs then retreat. Whilst dropping the bombs the bomber is detected / chased by one or more fighters. When the bomber recloaks the fighters continue to give chase despite not being able to "see" the target they're locked on to. (no valid intel) This will continue until new orders are given to the fighters, the fighters are killed or the bomber is killed. In a nutshell, the game engines weapon scripts / targeting routines have access to intel the player does not OR the fighters weapons do not know to disengage from a cloaked target. Currently there is no known fuction or process that we have access to that would modify this behavior as all of the targeting / weapon core scripts are part of the engine. (for speed)
Now this doesnt mean I dont know of an unconventional way to force a work around...
What i have in mind involves two units, the Real-Unit and a Dummy-Unit (helper). The Real-Unit is everything you'd expect, moves, shoots, takes orders, has a hitbox, receives damage BUT is listed as non-targetable. The Helper-Unit (refered to from the point as simply the helper) is a inert unit thats "attached" via script to the Real Unit. The Helper can not be selected, has no hitbox or provides any other fuction then to allow an enemy faction to target / fire at the real-units location. (hopefully striking its hitbox) Now here is the interesting part.... When cloaked, the Real-Unit deletes the Helper which forces the attacking units to disengage. (aka no longer a valid target) Uncloaking is what your expect, the reverse of before, thus allowing the opposing factions to "see" the real units true location.
Note: The Helper should share the same basic stats as the Real Unit so when a player mouses over it shows the correct hitpoints, icon, veterancy ect.
Two issues with this however.... the cloaking is absolute and not even Omni can see thru it. The helper unit counts towards the unit count, which can stall a players build production if its surpassed.
Resin