For mapping with Airborne Support go to the respective post!
1. Will work in custom maps?
2. How to add them to my map?
To the first question, yes they will work in ANY map created or ANY map that will be available in the future.
So this also answer the second question, you don't need to do anything different on your map to make all the 22 new gametypes works.
But of course, bad mapping or incomplete maps causes few limitations of the gametypes available to that map.
If you simply don't add the Heli and his paths to your map, of course will be impossible to play Chopper, or will be a little boring to play Escape, Escort, Waves, etc... since no one will come to help you in the right moment.
But aside Chopper, they all will work aside that little problem.
So if you don't add HQ to your map, all gametypes that use HQ objects like Nuke or Hack will not work as well, and goes on...
Other mappers simply changed the names of the entities (I don't know why) which make my work a lot harder to code upside their dirty work, aside his amazing looking map.
In some maps I coded to avoid that error because I loved the map so much that I just can't waste the map, but I can't do that to every bad map available, is more easy, fast and RIGHT to the mapper fix his own work.
So if you did it right, will work it right... so if in some map doesn't work some gametype, it's because the mapper, and not me... please don't blame me for other's bad work...
Here are the tips and all the info you need to know about how to make good maps (coding world) for COD4 and Frontlines.
The 2 rules of success!
1. Never use more xmodels than the map mp_citystreets, this will avoid the 1000 xmodels limit error.
2. Add all the available gametypes and spawnpoints to your map following the IW rules.
Frontlines Gametypes Objects
Here are the list of all the gametypes that you need to have on your map to work each gametype, of course if your map have all 6 original gametypes plus the heli support, all gametypes will work fine.
Assault = SD (Sab optional)
Assassin = SD/TDM (SAB optional) (Heli support)
Battlefront = SD or TDM / DOM
Commander = SD or TDM
Chopper = SD or TDM (Heli support)
Docs = SAB/HQ
Escape = SD (SAB optional) (Heli support)
Escort = SD (SAB optional) (Heli support)
Exterminate = TDM
Flags = DOM/SD
Hack = HQ/SD (SAB optional)
Hill = DOM
Nuke = HQ/SD (SAB optional)
Objective = SD (SAB optional)
Rescue = SD (SAB optional) (Heli support)
Spy = SD/TDM (SAB optional) (Heli support)
Targets = SD (SAB optional)
Unity = DOM
Uprising = SD/HQ (SAB optional) (Heli support)
VIP = SD or TDM
Waves = SD (Heli support) / DOM
Wrath = TDM
Updated 16.12.2009!!!

