WolvenKit is the Witcher 3 Modding Community's mod editor. This means, it is a unified program to view and edit all the game's assets, e.g. the textures, models (w2mesh) and all the other game's files like entity files, behaviorgraphs, quest files etc etc.
Quick Start: Using WolvenKit should be easy and intuitive: All starts with creating a new Mod Project. Once you did this, you can use WolvenKit to browse the game's assets or create your own. Use the Asset Browser to browse the game files. To add a game file to your mod, click "Add to Mod". If you did your changes to the file, click Pack Mod (in the toolbar or the menu).
WolvenKit will ask you for two things on first launch: (WolvenKit will try to automatically fetch this information based on your steam/gog install) 1. The location of the Witcher 3 Game. 2. The location of the Witcher 3 Modkit: If you don't already have the Modkit installed, you need to download it here: https://www.nexusmods.com/witcher3/mods/3173
The location of the uncooked files depot is set automatically to the r4depot of wcc_lite.
Make sure you have no spaces in the path to the Modkit! WolvenKit will warn you in any case, but is best to install the Modkit in a location like e.g. D:\MODDING\Modkit.
There are some more setting found here:
Color Theme: Chose from 3 themes: Dark, Light and Blue
Uncooked Extension: Specify the image type when uncooking (exporting) textures from the game. Default is tga.
Disable Welcome Form: disables the welcome form surprisingly.
The first launch of WolvenKit may take some time (up to around 15minutes) indexing the game's files. Subsequent launches are very fast (around 1 minute).