I think you're referring to the
KKUTS shader, which is very versatile with lighting and shadows without losing that anime look, although it's not highly recommended if you intend to use it on clothing and hair due to its resource demands (especially if we're talking about hair composed of individual strands). When applied to several models in the same scene, older GPUs tend to experience significant FPS drops.
The most economical and fun shader to use is xukmi reflect, which closely simulates the effect of MMD models but is applied in the Unity engine. Honestly, it achieves better results than KKUTS, which I barely use for clothing.
Using and leveling matcap has been the best thing that's happened to me in my experience with Koikatsu. Even now, with a better GPU, I still use it to give my GPU that extra "effort" for DisplaceTex.
Here I have two different uses of the matcap with the normal map and detail mask. I've actually achieved more detailed and satisfying results than
KKUTS.
The wolf mask uses a matcap with three shadow layers, and it really achieves a result that can even be applied to the entire model without putting a heavy load on resources, as other shaders might. I'm still working on that mask;
it has 10,000 polygons, and it's difficult to reduce it without losing the smoothing, even with the normal map (just in case). And the body uses a metallic matcap but with the reflection value reduced. It's a symbiotic relationship with the normal map and detail mask because it doesn't dull the image but rather enhances its effects. Notice the neck and the subtle shadow detail.
I have the game without shadows and heavy lighting; enabling it doesn't make much of a difference either. It's an economical method, if you ask me.
