[FAQ] Modern Warfare 2 GSCs/Modding

**[MPGH]master131** · 09-25-2010

FAQ (Frequently-Asked-Questions)

Getting started/Common mistakes:
Q. What exactly is a GSC?
A. A GSC is a script used by the Call of Duty series to run game functions and peform actions. GSCs are simple text files that have no formatting (Microsoft Word is a big no no!).

Q. I am new to modding and don't know where to start. What should I do?
A. You should learn the BASICS of C (don't get too much into the C specific functions). Also, you should have a look in Josephlittle's mini-tutorial here.

Q. I tried to learn a little bit of C but failed miserably. Can I still make mods?
A. Of course you can. There is a little guide here written for COD4 but is still VERY helpful. Even I learnt some little things here and there.

Q. What is the difference between setDvar and setClientDvar?
A. setDvar is used for server wide settings such as "jump_height" and "g_gravity" while setClientDvar is used for player only settings such as "r_brightness" (Note that when using setClientDvar you add self, player or an entity behind it otherwise you will get an error).

Q. I have a syntax error. What should I do?
A. Use a tool such as ffViewer or GSC Fixer 1.0 to help display/fix the error. Make sure you do that BEFORE asking on the forum.

Tips/Resources:
Q. Where can I find a list of common MW2 commands?
A. You can find many here on this site. It may be for COD4 but IW have kept many of those commands and most of them still work in MW2. If it says SP Only then you obviously can't use the command on MP.

Q. I'm looking for a specific thread from another file but don't know where to look for it. What should I do?
A. Have a look at this HUGE pastebin link. Credits go to Shikaah! for the list. (May lag Firefox users. Open the link in IE for safety reasons).

Q. I'm looking for a code/snippet. Where can I find it?
A. Have a look in Abstracts' GSC code list. You may find something you need in there.

Also, here are list of snippets/mini-tutorials I've posted on MPGH:
Teleport turrets to your crosshair
17 bots vs. 1 player
Disabling class changing

Q. How do I display text in the middle of the screen or in the killfeed?
A. Use self iPrintlnBold("text here") or self iPrintln("text here").

3rd Party Software:
Editing GSCs
Q. What should I use to edit GSCs?
A. You should use any text editor but I recommend Notepad++ because if you click on an open brace, it highlights in red and will show you the closing brace that's 'linked' to it.

Q. Can I use Microsoft Word to edit GSCs?
A. No. Using Microsoft Word is not a good idea because it tends to leave hidden text/extra bytes at the start of the file and screws up your mods.

MW2 Liberation
Q. Why can't I find MW2 Liberation here?
A. MW2 Liberation contains advertising and links to another forum therefore it is not allowed here.

Q. What hotkeys can I use to do things on Liberation?
A. Here is a list of what I have gathered:

Code:

F1 - Draw FPS
F2 - Open console
F3 - Change team
F4 - Change server settings
F5 - Force host/Unlimited ammo
F6 - Switch to opposite team
Alt+F1 - Change mod
Alt+F2 - Restart match
Alt+F5 - God mode
Alt+F6 - Middle finger spam

Q. Can I get banned from using it?
A. All public disablers eventually become detected so it is not safe.

Mod Loader
Q. How do I change mods without closing MW2?
A. Close Mod Loader and edit the config file to the mod you want. Run Mod Loader again and click Auto-Inject. Wait atleast 5 seconds and go back to the MW2 window. Type map_restart into the console and then it should work.

GSC Fixers/Tools:
GSC Fixer 1.0 by master131
Q. I don't see the error displayed in the console?
A. Look under these lines:

Code:

------- Game Initialization -------
gamename: IW4
gamedate: Jun 10 2010
        self iPrintlnBold("MPGH ftw";CL_Disconnect called for local client 0

Q. Does the tool work when MW2 displays 'Unknown function'?
A. No. It does not work because sometimes MW2 can't determine what exactly the unknown function was.

Q. What does it mean if I get an open brace as the mistake?
A. You may be missing a closing brace or have too many.

Q. What if a line of code appears as the mistake but nothing is wrong with it?
A. Look at the code under it because it might be incorrect or not valid.

ffViewer
Q. What should I do if ffViewer never comes up after waiting for more than 1 minute?
A. Run the ffViewer through the original .zip file. For some reason, it works. If WinRAR asks to update the original archive, click Yes.

Q. How do I check for syntax errors?
A. Click File > Open and browse to your patch_mp.ff file which can be found inside the zone/english folder of your MW2 directory. Click on the file you are checking (_rank.gsc) and then copy and paste the contents of your edited file into the box on the right. Click Tools > Syntax Checker.

Q. Why does ffViewer spam me with removeRankHUD errors?
A. I have absolutely no idea but you should ignore it.

Q. Why does ffViewer say there is an error on a line but there's nothing wrong with it?
A. If you begin a thread and the thread name contains an opening brace on the first line, it tends to say that. Example - doDvars() {

GSC Compiler v1.0 by AcE.bu50t
Q. What exactly is GSC Compiler v1.0?
A. GSC Compiler v1.0 is a little alternative to ffViewer and Notepad that allows you check for errors on-the-fly and create GSC mods. A really cool feature is to be able to have a raw backup just in-case something happens.

Q. Why is it so buggy?
A. It's buggy because it is in it's beta stages and is not fully complete!

Download:
GSC Fixer v1.0
ffViewer
GSC Compiler v1.0

Script Compile Error:
Q. What does syntax error mean?
A. Syntax error means that there is a mistake and it cannot continue. Some common mistakes are having too many or too little opening/closing brackets

Q. What does bad token mean?
A. Bad token means that you have 1 quotation mark and are missing the other OR have a strange symbol that the game does not recognise such as: .

Q. What does unknown function mean?
A. Unknown function means you have something in one of your GSCs that MW2 defines as something that has no value, doesn't exist or hasn't been declared. Example - self getPlayerBirthday(); /

Q. What does "expression list must have 1 or 3 parameters" mean?
A. This is an error than some of you QCZM fans may come across. This normally means you are missing a number in one of the create functions. Example - CreateBlocks((773, 1080), (0, 90, 0));