Black normals

[abgenullt]

Godot version

4 alpha 11

System information

Windows 10, Vulkan, RX560

Issue description

Hi,

I've recently got a problem with normal maps.
I tried different model formats (gltf, fbx) and normal maps but can't get rid of this black sides of the model.

Is this a bug or is there a workaround?

Regards
abgenullt

Steps to reproduce

Import a model and a normal map. Assign a new material with a normal map to it.

Minimal reproduction project

test.zip

[abgenullt]

I still have this problem with version 4.1.1. Can someone confirm this issue?

[Calinou]

I've never been able to reproduce this in any of my projects, nor the official demo projects. The issue is likely with the source model itself.

[Stwend]

When I open the test project with Godot 4.1 stable, the normal map is detected and displayed as what seems to be a red-and-alpha channel icon in the file browser and as a regular RG-compressed normal map in the inspector.
The scene itself looks fine when enabling the default environment and sun - the only difference between the models seems to be a slightly darker shadow color:

Same goes for 4.1.2 RC1. My system specs are: Win11, RTX 3070 Ti.

//edit: Here's what the normal buffer looks like:

[abgenullt]

Thank you for your affort.. I really don't know why but after I deleted and re-downloaded the project, the problem was gone...

[abgenullt]

I will test more models and check, if I can find the reason..

[Calinou]

This may be due to the same cause as #64854.

[abgenullt]

I don't think so. I have this problem on freshly imported models, too. If I find a the reason, I will let you know.

[abgenullt]

Ok, that is very strange. If I copy the working model from the test project to a new, blank project (v 4.1.2) and activate the normal map, I get the same black normals on one side again..

I get the same effect on two complete different systems.
I really don't know what is going on here..
test2.zip