Godot-Cel-Shader VS blender

I'm using this cell shader for my game https://github.com/EXPWorlds/Godot-Cel-Shader. After applying it to my mesh, a few of the faces disappear as shown by the screenshots bellow. I've flipped the normals and reimported, but nothing changed. Any help would be appreciated

(1) https://github.com/EXPWorlds/Godot-Cel-Shader

And about cell shading... did you see this shader?

Please try looking through some large open source projects and contributing major contributions by familiarizing yourself with the code base, learning multiple programming languages, and not having major bugs in your code. I'd imagine you wouldn't want to do this.

Here is a weblink: https://github.com/blender/blender

This for example is the complete source for blenders procedural noise functions: https://github.com/blender/blender/blob/main/source/blender/blenlib/intern/noise.cc

Maybe you're only using object lights. To make it look like Material Preview, you'd want to use an environment texture [instead]. If you don't want to have to find them in the blender folders, here are the ones listed in Material Preview, forest.exr being the default

forest.exr https://github.com/blender/blender/tree/master/release/datafiles/studiolights/world

Everything was good. And then a developer decided to abandon the custom CLAMP macro and use the standard std::clamp function. And the commit that supposed to make the code better looked like this:

Or simply git clone official public mirror and build it yourself.