Best way to fix gaps in toon outlines when using inverted hull method?

I’ve been experimenting a lot with materials in an attempt to create a toon shader that resembles Guilty Gear Strive, at least in a more simplified manner. To achieve this I decided to use the inverted hull method.
My main issue at the moment is figuring out how best to fix these weird gaps in the outlines.
(I’ve increased the thickness of the lines to make it more visible)

I imported the model into blender and created a model with flipped normals, then applied a simple emissive material with a black color to it, to see if that may improve the issue.

This appears to have at least helped with the spacing between lines, however now there’s the matter of manually scaling the object, then lining it up with the original mesh. Which I’m sure may be part of the reason why no one seems to do it this way.

What I’m really asking about here is what is if anyone knows a way to fix the standard method of inverse hull, or if maybe my spin on it could be made to work?
Or really if there is any advise to be given on toon outlines, I’d greatly appreciate it.

Hi @Kotaru_1!

I know the thread is kinda old now, but I wanted to ask if you had any luck with your outlines?
I am currently stuck with the same problem as you described.

The gaps are caused by by the split vertex normals of sharp edged geometry. Set the inverse hull to be entirely smooth shaded so that each vertex shares just one vertex normal, and then they cannot tear apart.

Because the hull will not be shaded normally, being totally smooth shouldn’t any cause other visual issues.