There are two parts to graphics modding:
- Assets (images or models), stored inside /gfx folder
- Logical names (starting with GFX_ prefix) mapping to these assets, defined inside /interface/*.gfx files.
Logical names are then either referenced from other script files, or are based on naming convention hardcoded in the engine.
Some recommended editors include:
- .tga (Truevision Targa)
- .dds (DirectDraw Surface): requires a plugin to use with GIMP or Photoshop, but works natively with Paint.NET.
- .xac/.xsm: licensed format for 3D models and animations
- .mesh/.anim: Paradox developed format for 3D models and animations. Used first in EU4 and in CK2 since Patch 2.2 (Charlemagne). Can be converted to via the JoroDox mod making tool.
- 主条目：Portrait modding
This folder contains bits of faces that are stuck together to form portraits.
Coats of arms
Contains flag frames and CoA pattern & frames.
Flags are used for titles above baronies, but only for religions where
has_coa_on_barony_only = yes.
The game typically crashes if the flag is any of the following: is not 128x128, is not 24-bit, or is uncompressed.
Warning: a missing flag for a title in flags\ folder will cause wrong flags to appear for most titles, due to a shift. a good way to work around this while working on other aspects of the mod, is to give the nations placeholder flags.
Main game loads from /interface/ for christian religion group, but some assets are overridden when playing religions from other groups:
- from /indian_interface folder for indian_group religion group
- from /muslim_interface folder for muslim religion group
- from /zoroastrian_interface folder for zoroastrian_group religion group
- from /jews_interface folder for jewish_group religion group
- from /pagan_interface folder for pagan_group religion group
New religion groups load from /interface/ folder, and cannot have their own interface.
Mods cannot override assets in religion group folders, as the override is only processed for main game.
For optimal compression, loading screens should be saved with DTX1 compression / no mimaps.
The order loading screens appear is random, except:
- load_0.dds, which is used as splash screen
- the image with highest file name (ex: load_13.dds) has a far more likely chance (50% as of patch 2.8.2) to appear first.