strange normal map behaviour on some meshes

[djmaesen]

Godot version

4.0 beta 12

System information

windows 10

Issue description

im getting artifacts on some meshes. the normal map isnt applied correctly.

Steps to reproduce

ive attached the barrel model to reproduce the issue.

import the model and apply a standard material with the maps provided.

Minimal reproduction project

exploBarrel.zip

[Calinou]

Is the mesh triangulated on export, either by using a Triangulate modifier in Blender and ensuring Apply Modifiers is enabled in the export dialog, or by checking an appropriate triangulate option in the exporter?

This is more reliable than letting the game engine do it. (This advice is not specific to Godot; it applies to any 3D application you'd export a mesh to.)

[djmaesen]

Is the mesh triangulated on export, either by using a Triangulate modifier in Blender and ensuring Apply Modifiers is enabled in the export dialog, or by checking an appropriate triangulate option in the exporter?

This is more reliable than letting the game engine do it. (This advice is not specific to Godot; it applies to any 3D application you'd export a mesh to.)

the barrel isnt
but the weapon and arms are triangulated

[djmaesen]

Is the mesh triangulated on export, either by using a Triangulate modifier in Blender and ensuring Apply Modifiers is enabled in the export dialog, or by checking an appropriate triangulate option in the exporter?

This is more reliable than letting the game engine do it. (This advice is not specific to Godot; it applies to any 3D application you'd export a mesh to.)

i just tried the barrel with triangulation applied before import, same result.

[Flavelius]

i had a look at the file and it actually seems to be a godot issue (i also tried exporting with different modifications (like merged verts, non-sharp, non/autosmooth, normal edit modifier etc) and export options. Blender's mesh analysis tools also confirm that there are no normal issues or overlaps etc. And when importing the barrel in a different orientation, those artifacts even occur in different locations in godot.

[tagcode]

On Godot 4.0.2, I'm having issue with normal mapped materials and normals that point at (0, 0, -1).

When I adjust normals near Z=-1, the normalmap issues goes away:
float dot = normal.Dot(Vector3.Forward); if (dot > 0.99f) normal = new Vector3(0.1f, 0.1f, -0.9f).Normalized();

EDIT!: The issue goes away when I calculate tangents manually. It seems to be in the ArrayMesh's automatic tangent calculation.

I've ran this exact same mesh procedure on Unity3D and Stride3D. This automatic tangent issue appears only on Godot.