How to add a new T-shirt ?
To add a new T-shirt, you should extract all these directories & files, using QPed :
Data\Models\Textures : contains all the textures, both for male & female
Scripts\GameSys.Ini : contains the number of available outfit styles for each part
Step 1 : create the new T-shirt (or any other outfit part), and save it in the correct directory (look into the .pak "Data/Models/Textures") with a correct name : "ShirtXX.jpg" where "XX" is the number of the new T-shirt
Step 2 : edit "GameSys.Ini", and locate this text : "NbPreset & NbType & FirstType" . Just under, you'll see the list of all possible outfit parts. You just have to increase by one the "NbType" of the part you added a style to. For a male T-shirt, it's [Male_Shirt] .
Step 3, only for Female's T-shirt & skirt, and the Male's T-Shirt : you'll have to define on what 3D model to put the new T-shirt or skirt texture. To do so, open "Data\Models\Textures\Female.Ini" (or Male.ini) and look for [Female/Shirt], [Female/Shorts] or [Male/Shirt]. If you add a T-shirt, look this line:
Model = Tshirt01 1-5 Tshirt02 6-11
and change it to :
Model = Tshirt01 1-5 12 Tshirt02 6-11
Model = Tshirt01 1-5 Tshirt02 6-11 12
depending if you want to use the 1st or 2nd 3D model. The 1st model is the shirt with short sleeves, and the 2nd model is the sleeveless shirt.
For the T-shirt, you'll also need to define a mask to tell the engine what part is the skin in the texture.
Step 4 : you should be done now, just launch the game, and look if your new part style is available in the outfit customization screen..!
THIS IS FROM HTM, HOPE IT HELPS