KoikatsuModdingTools (Patreon)

https://github.com/IllusionMods/KoikatsuModdingTools

I've been working on a set of modding tools for creating Koikatsu mods in Unity. These modding tools should make it much more simple and easy to create mods. Unity allows you to use a variety of file formats so you can use .psd, .png, etc. for your textures without needing to convert to some other format. Likewise with meshes, you can use .obj, .fbx, or even .blend files. When using SB3UGS you have to convert textures to .dds and meshes to .fbx, when using Unity these conversions are handled for you.

KKModTools will compile asset bundles and zip up the mod with its manifest.xml and list files for you, allowing you to create a functional mod at the click of a button. You can also create a version of the mod for testing which zips only the list files and copies the asset bundles to your game folder, allowing you to quickly test your mod by using the "Clear AssetBundle Cache" feature of RuntimeUnityEditor. Simply build your test zipmod, clear AB cache, and for accessories swap to a different one and back or for studio items delete and add it to see your changes in game without needing to restart the game.

This project includes example projects for various types of mods, such as accessories, textures, studio items, head types, UncensorSelector, and MaterialEditor shaders. You can also create maps for use in Free H complete with H points, time of day, lighting, etc. 

There are some nice quality of life features in this project and I hope to add more in the future, for example generating bone lists for adding FK to studio items. You can read more about the project on the main page
https://github.com/IllusionMods/KoikatsuModdingTools
Read more about the various tools and how to use them on the wiki
https://github.com/IllusionMods/KoikatsuModdingTools/wiki

Why Unity?

In the past, using Unity for mod creation has been a challenge due to shaders being inaccessible. Thanks to enimaroah and his updates to SB3UGS, we've solved this problem and now shaders from the game can be used for developing mods from within Unity.

I wrote a set of placeholder shaders for each of the Koikatsu shaders, these shaders are not functional but they have all the properties of the real shaders so you can assign them to materials and configure them. When building asset bundles, SB3UGS scripts are run to swap these placeholder shaders out for the real shaders so that your asset bundles compile with the proper, functioning shaders.

SB3UGS vs KoikatsuModdingTools

 KoikatsuModdingTools and SB3UGS are both tools for creating mods, both implemented in very different ways. KKModTools is a set of scripts for use in Unity, SB3UGS is a stand alone application. Unity's install size is pretty big (2.2gb) compared to SB3UGS (22mb). KKModTools is specifically for developing mods for Koikatsu whereas SB3UGS supports a variety of Unity versions as well as older, non-Unity Illusion file formats. SB3UGS is necessary for extracting meshes from the game files if you want to make modifications to them.  SB3UGS is invaluable for examining the contents of asset bundles built by this project, and SB3UGS scripts are required for shader swapping without which this project would be worthless.

On the other hand, Unity is very well documented. Unity allows you to write your own c# scripts, in fact that's what this project is. All parts of this project's code are available to you and can be modified to your liking. Unity accepts a wide variety of file formats and converts them for you. It even converts standard style normalmaps in to the grey style normalmaps when building asset bundles. UtinyRipper can rip assets from other Unity games in to a format which you can just drop in to this project which makes porting assets from other Unity extremely fast.

In short, KoikatsuModdingTools should automate the more tedious parts of mod making allowing you to create more mods in less time.  SB3UGS is still an essential part of mod creation.

Converting mods to KoikatsuModdingTools

You can convert any mods you've created in the past to a KKModTools project very quickly.
https://github.com/IllusionMods/KoikatsuModdingTools/wiki/Importing-Contents-Of-AssetBundles
I wrote this script for converting my mods so that I could test all the various mod types in KKModTools and create the example projects. You can use this script to convert your own mods as well.

If you have any problems please visit the Koikatsu Discord mod modelling channel. I will be there to answer questions about this project and other experienced modders can answer any other modding related questions you may have.