Normals Appear 45 Degrees off

[Donny000]

Hey everyone, I’m having an issue that I’m fairly certain is an issue with UVs but I haven’t been able to come up with or find a a solution for it.

So the lighting within this tunnel asset is behaving strangely, on the right side of the point light, it seems to be okay, on the right though, there’s the heavy shadow and also it seems to be at 45 degrees for some reason. No matter how I transform my UVs the lighting is always off by 45 degrees, and I can’t get even lighting across the texture.

For reference, this is part of an attempt with trim sheets (one shell pictured):

If anyone can help or has any ideas, that would be great. Thanks in advance!

[ClockworkOcean]

It will probably be the normals on the model, not the UVs

[Donny000]

Thanks for replying!

The thing is, the UVs seem okay (from my understanding) if I use the check pattern in Maya:

[ClockworkOcean]

That’s right, it’s the mesh normals

I don’t use Maya, but there is a way to tell the mesh which way each face is oriented.

[Donny000]

Thanks, but again, my normals seem okay. Unless of course, I’ve misunderstanding you.

[ClockworkOcean]

Ok, I don’t suppose the material has a world aligned texture in it? ( you would probably know )

You might also try inverting the green channel on the normal texture in the engine ( assuming you made it in Maya )

[Donny000]

As far as I know, nothing should be world aligned in this texture (open in new tab for full res):

And unfortunately, flipping the green channel just span the issue 180 degrees.

[ClockworkOcean]

You’re normals are coming from a world position node ( ie world aligned )

Do you really need that, can you just turn if off?

This will be why you have the problem.

I don’t know if you coded that material yourself, or got it from the market, but very often in world aligned applications, the normals are calculated incorrectly.

[Donny000]

Okay, good to know. I created this shader myself for vertex painting during my university project so understandable that I messed up somewhere

Which node is is it that you think may be causing the issue? The only world aligned part I can see is the “rain” effect which is a for panning a 3D noise texture.

[ClockworkOcean]

I don’t think in fact, the shader has normals ( it’s a bit hard to check ), they seem to be vertex painted.

Just take the normals from an actual normal map, that’s all.

Or set that IF node so that you only get ‘from normals’

[Donny000]

I tried plugging the base normal texture straight in and it had no effect unfortunately.

(And just in case the settings have any glaring issues)

[ClockworkOcean]

Right, but are the UVs correct for just plugging it in?

What happens when you just plug the brick texture into the albedo slot?

[Donny000]

This is it with the albedo and normal plugged straight into the final node:

[ClockworkOcean]

It looks ok from here, no?

[Donny000]

Everything apart from the right of the point light looks okay, surely there shouldn’t be such a deep shadow there if the light is emitting in all directions?

[ClockworkOcean]

The normals look ok to me. If you compare it to the first pic you posted.

[Donny000]

It does look a lot better, I’ll admit So the problem is something in the way that I’m combining the normals for vertex painting then? As far as you can tell, have I used the wrong kind of node or something for normals?

[ClockworkOcean]

You were combining normals with height maps and other things, it seemed there

Perhaps it’s not possible to get the default normal out of the shader, I wasn’t very easy to check.

[Donny000]

So I put some more work into getting to the bottom of this and you absolutely put me on the right path with the normal maps.

Turns out that at some point, Unreal had imported some of my normal maps not as normals. So after going through and ensuring the were all set correctly as normals, with the right compressions, and SRGB off, everything works just fine!

(Why is it always one little option that wrecks things? )