This tutorial will teach you how to create your own AItype and Character assets in Call of Duty 4 Assets Manager!

In simpler words, by customizing those assets you will be able to make your own head and body model combinations on AIs.

First things first, what are AItype and Character assets?

AItypes: Those assets are responsible for giving the AI spawners you place in Radiant some basic settings likewhat primary and secondary gun the AI will have, what team and other settings. These assets when converted and ready to use, are usable in the Actor menu in Radiant.

Characters: These assets combine head and body xmodels. You chan also use the battlechatter nationality voice selection.

Step 1: Preparing your xmodels.

For most AI characters, Call of Duty 4 and later COD games use a combination of HEAD and BODY models. With some exceptions. Call of Duty 4 Combines the HEAD with HANDs in one model and a Handless and Headless body model for BODY. In CHARACTER assets you combine those two the appropriate way! You can see the models in Radiant.You have to make sure you use the right HEAD+HAND model with the proper BODY model from COD4. Some hands don't fit some body models right and they will look wrong. So experiment with them and see what fits what.

IMPORTANT: If you want to use Xmodels from later COD games like MW2, BO1, MW3 and so on.. Careful of the bone/rig/joint number! COD4 has a limit of 128 bones for each Actor. If your BODY+HEAD model exceeds this limit the map won't run and you will need to edit or remove the asset from the map. This can happen if you Combine a COD4 HEAD+HAND model with a MW2 BODY model that already has hands. This will turn out that the final result will have two pairs of hands which dramatically increases the bone limit. Another example is the head mouth joints. In MW3 given the better detail on mouth dialogues, they  use a lot more joints for mouth animations. If you try to combine a MW3 head with a COD4 body, then you will surely get above 128 total bones.A way to solve this is edit the raw model in Maya and remove some spare joints.

Step 2: Combining Xmodels in Character asset.

Alright, here's where the fun begins. Launch Assets Manager and create/save a new GDT of your own as I hope you already know.Create a new Character Asset. Name it any way you want just so it fits the combination you want to make.

Example: I want to combine the HEAHD/HAND model and BODY model of Kamarov character from original COD4.

The models are: 
HEAD/HAND: head_sp_loyalist_tom_hat_body_d 

BODY: body_sp_russian_loyalist_d

So in your new Character asset (lets call it Kamarov1 to avoid overwriting)
in the BODY field you add this: body_sp_russian_loyalist_d
and in the HEAD field this: head_sp_loyalist_tom_hat_body_d 

You can also set his voice to russian if you like so when he randomly plays battlechatter, he will speak russian.
Then since we are ready, PC convert> Current Asset OnlyAnd it should be done!

Step 3: Restart Assets Manager.

Every time we convert a Character asset, it appears that we have to restart Assets Manager so our new Asset is usable in other settings like the AItype we want to do next. If we don't, the asset won't appear in the Character list that AItype asset will ask. At least that's what happens in my case, but I think it's like that on everyone.

Don't worry the asset is saved once you Convert it or save the GDT.

Step 4A: Creating your own AI Type Asset!

Alright, we have Assets manager open again, now open your GDT file, and on the top-left list under the Entry buttons scroll up to AITYPE. Then New Entry. Now the underscores you will put in the name of the new asset will define the path in the radiant Actor selection.

For example: The ORIGINAL Kamarov Aitype is in this path in the 2D menu in radiant:actor>ally>hero>kamarov>russian.
Which means that the  AItype is called: ally_hero_kamarov_russian.

Notice that the actor is not included in the name because it's already under actor since it's an AItype Asset, so you don't have to put the actor word first.

Now in our case let's call him this: ally_hero_kamarov_russian_test
We name him differently so we don't overwrite the original asset.

It is highly suggested that you never overwrite ANY KIND of original assets!

Okay we named him now let's go to further settings!

Step 4B: Setting up the AItype Asset.

Now that we have our own AItype asset we can start giving it the settings we like.

On top you can see the radiantmodel option. There, you can put a bodymodel that will represent which which actor this AItype is. We usually put the bodymodel we added in the character so in this case,
put this: body_sp_russian_loyalist_d

Animtree is not really needed, ignore that one.

Keep accuracy and heath 0.2 and 100 by default.

Now Weapons!
In original COD4 Kamarov has an AK47 with Grenade Launcher as Primary Weapon.
I'm not sure about his secondary or sidearm but never mind.
Let's make things more fun in our case. 

To set a Primary Weapon for Kamarov select the field next to the "weapon" word and scroll to your desired weapon!

CAREFUL: Make sure it's NOT A MULTIPLAYER weapon! You can tell this by seeing in the name of the weapon.It has a _mp usually at the end of its name.

Anyway, in our case let's put "saw" A US weapon in russian hands!Secondary weapon: Let's put a normal AK47. (Secondary weapons are never used by default from AIs as far as I know, so it can be any SP weapon.)

Sideram is used when the AI is exposed and out of ammo from the primary weapon. 
There are two fields of sidearms it's good that you put the same on both but I think they are linked so it's auto. Let's put a desert eagle for our Kamarov!Scroll down to "deserteagle" and select it.

Now we have many choices for grenade weapon.
I suggest sticking to the normal frag grenades.the name is "fraggrenade".

Set team to "allies" or "axis" if you like to fight him ;)

Type: "Human".

And then you see the option character1 down below.
THAT'S where we set our character asset to our new AItype asset!
Click the 3 dots at the right of the character1 field and select our Kamarov1 asset!
(If you don't see your asset you probably didn't follow Step 3)

Save, and convert>current asset.


Step 5: Using the Actor in your map!

Open Radiant, in 2D menu, go to actor>ally>hero>kamarov>russian>test1
And you should have your custom AItype character ready to be used in your map!

OPTIONAL STEP: Random Combinations of Head and Body Models.

Assuming you have a series of head and body models that all fit each-other and you want to combine them randomly on ONE Aitype spawner then you will need to use the xmodelalias assets.

Those are pretty easy to use.
Simply create a new one for head xmodels and assign the head xmodelsx
Let’s say head1, head2, head3, head4.
Done, save, convert.

Now create another one for bodies, assign the bodies: body1, body2, body3.
Done, save, convert.

Then go to your character asset and under head there is the Body Alias option.
Select your Xmodelalias asset with your Body Xmodels you previously converted.

And do the same for head alias xmodels.

When you are done with both, convert character and now the AI will spawn with those assigned models combined randomly.

Have fun! I hope this tutorial helped!