3ds Max from Autodesk is the program they use.
You could also use "Blender" but the stuff you do would need to get converted into 3ds Max to make it compatible with GTA, as I got told.
https://www.autodesk.com/products/3ds-max/overview
You could also use "Blender" but the stuff you do would need to get converted into 3ds Max to make it compatible with GTA, as I got told.
https://www.autodesk.com/products/3ds-max/overview
///