I have some questions about FBX, OBJ, and the gamma of textures for Unity

[zeidhan29]

Without going into too much detail, I'd like to learn more about the post-Unity process for mods, and if you know of any easier ways to prepare an FBX model (or export an OBJ as FBX) that yield better results:

- External tools
- Blender plugins
- Guides
- Or direct converters
For example, when I've exported MMD models to FBX, especially those with armatures, I find it difficult to manually translate the FK bones or simplify the MMD-to-FBX process. It usually takes me an hour with an armature, and that feels like too much time for a single result.

I'd also like to know how to configure accessory textures so they don't appear too dark in the final output within Koikatsu or CharaStudio.

Any way you can share your knowledge would be greatly appreciated.

 

[saltedfish]

I'd recommend getting the CATS Blender plugin if you haven't already. It can do several things that can speed up the workflow by a lot, such as being able to delete all unused bones.
You can use this Photoshop filter made by coolcoffee to adjust the textures to fit Koi's in-game filter. If you don't want to use Photoshop you can use Photopea instead.
Also, I was wondering if you could maybe elaborate on translating the FK bones please? Such as for studio items or character accessories?

 

[zeidhan29]

I'd recommend getting the CATS Blender plugin if you haven't already. It can do several things that can speed up the workflow by a lot, such as being able to delete all unused bones.
You can use this Photoshop filter made by coolcoffee to adjust the textures to fit Koi's in-game filter. If you don't want to use Photoshop you can use Photopea instead.
Also, I was wondering if you could maybe elaborate on translating the FK bones please? Such as for studio items or character accessories?

I use Cats in Blender to save FBX files only, as it has a setting to prevent the export of unnecessary content that only increases file size upon import. This add-on is only designed for character models that you want to import into Unity for later use in VRChat, which is why it gives you a warning when importing MMD stages or props. For that, it's better to use the MMD add-on for Blender, which also solves the texture and node issues, allowing you to set them to the Principled BSDF node, which is compatible with everything.

It's a shame that Cats doesn't include this feature, since XPS models have their own exclusive node that you have to manually convert to Principled BSDF, otherwise they won't export to FBX.

Regarding textures, I use KKImageConverter software, which restructures textures. You don't need to set it to linear or gamma settings to avoid darkening them.

Finally, both the CATS add-on and the MMD add-on have their own translator. Before applying it, it asks you to choose what to translate. Of course, with this version and my limited Python knowledge, I've received errors or even been blocked by Google Translate due to several requests made in such a short time. This made me realize that both add-ons translate bone by bone, blendshape by blendshape, meshes, and materials one by one in single searches. Currently, I translate blendshapes and bones manually using the browser. It's time-consuming, and I can spend two whole days translating 10 props or stages for a single zipmod. It's not the ideal workflow, but I prefer this to worrying about the topology of the models (which isn't very demanding in MMD models, at least not in older ones).

Sorry if I went on too long; I've been taking some Blender classes with a friend lately.

I also discovered that Unity, in the version used to create mods for Koikatsu and Koikatsu Sunshine (I use this one and not the newer version that's only for Sunshine, because I've noticed that most people use Koikatsu After School), only accepts models with a maximum of 65,000 faces. Beyond that, it splits the model into two meshes, which is usually a problem if it includes blendshapes, as it won't load them. And believe me, there's no written guide that explains this and the reason behind it. If you have models that exceed that limit, that's not a problem either. You just need to manually separate the meshes in Blender and then save it as is; none of the submeshes should exceed that limit.

Anyway, I'll take your suggestions as a process to follow next time I make mods; maybe it will streamline my workflow a bit.

THANKS U.

 

[saltedfish]

Oh yes, mmd-tools is definitely superior to CATS in terms of importing .pmx models. I actually completely forgot CATS could load MMD models so I just immediately assumed you already had mmd-tools LOL. Apologies.
But manually translating every blendshape and bone...😵 I admire your effort! If you're porting full character models with the standard mmd model rig and have PMXEditor, you could use its batch renamer function to automatically rename the bones and morphs. （Here's a tutorial for it if you want it, but you don't need to change the _data list.) It could leave some extra untranslated bones, but I hope it's still useful nontheless!
Also, I swear they increased the vertex limit in KKS to a much higher number. Peculiar to know it hasn't changed. 🤔

Thank you. I do hope my advice proves useful. Goodluck on your modding! 💖