Protruding geometry when using flat shading

[NecroDes]

Hello. I'm just starting to use this plugin. The documentation shows an example of how to make flat shading.
I inserted NORMAL = normalize(cross(dFdy(VERTEX), dFdx (VERTEX))); at the end of fragment shader in transvoxel_terrain_material.
Is there a way to get rid of this?

P.s. I am using the latest release version

[Zylann]

This is an artifact present due to a workaround to a caveat of marching cubes (which Transvoxel is based on): they can generate slivers, extremely thin or small triangles which are known to make the Jolt Physics addon unhappy, amongst other things.
So the way the implementation works around this is by clamping interpolation factors, which prevents triangles from becoming too thin, but a downside is in your case where shading is based on triangles and not on normals computed by the mesher, which makes them stand out.
Before this approach, the mesher was instead eliminating those triangles, which led microscopic holes to appear instead (and had a slightly higher performance cost). Which also caused various edge case issues.

If you don't want the current workaround to be active at all (and therefore you will get slivers), you can set the edge_clamp_margin property to 0 in the transvoxel mesher.

[NecroDes]

Thanks for the advice. Is there a list of games that use your plugin? It would be interesting to see a similar list as in the documentation of the Terrain3D plugin.

[Zylann]

I haven't considered adding a list of games because I don't know many projects using it. There are a few that used it at some point, others that might still be using it but haven't heard of in a while.