Strange shading problems caused by normal map

Hello,
I have a problem with a normal map on my character. The normal map is seamless but it causes a strange difference in shading between each UV Island. The mesh and UV are mirrored. I’m not able to find the source of the problem. I use Blender 2.80 with Eevee.

It’s hard to see what’s going on in your screenshots. The first one is very bright and the second one seems to have a color texture which makes it more confusing. If it’s a normal map problem, all the other material channels are unnecessary to show (including in the node editor).

Anyway, there seems to be several issues about your normal map. One about the mirroring and the other about UV island orientation. But I’d prefer to see a more comprehensive screenshot before giving a detailed answer.

Yeah, I have no idea what that is supposed to be. Is it a beach or something?

Just attach the .blend, or nobody will be able to help.

Till there is a blend ?? but try turning off alpha in your shader…see if that helps…also are you in evee or cycles?

Alright, I reduced the brightness of the scene. The normal map doesn’t have many bumps and dimples thus the colour texture looks like that and brightness made even flatter. That was the chest of a female anthro character. Here are zoomed out screenshots (censor bar, better be safe than sorry) The mesh and UV are mirrored, I use Eevee. I wonder if that can be fixed without scrapping the entire normal map. It was a pain in the butt to get baking settings just right.

Blend file: https://mega.nz/#!jBtUDI6a!Po9pmqtK03BjDG7lRfHTgv6VxxDrlHY0wdYGzsTYBkE Warning, NSFW.

Try exporting the model to different renderers. If it shows fine in others, but the UV island render differently in EEVEE, it’s likely flipped UV islands (polygon UV points clockwise direction changes from island to island)

The same issue I see in Blender’s Cycles and 3D Coat. How to flip these UV Islands? What I found only says about flipping/mirroring UV island by X axis.
I checked which direction normals face, all of them point out the mesh.

Sorry but I won’t download a 60Mb file for a normal map issue.
From your screenshots and comments, it seems you have some basics to learn on material processing (which is fine, we all do at some point), but most importantly, please narrow down the content of your blend file to what is relevant. This would make it easier for us to help you and it’s generally a good thing to be moderate with online file transfer.

Anyway, from the screenshots, here is the first issue I see with your normal map (and there are 2 more but I keep the second one for tomorrow 'cause it’s late and I’d still like to see the surface without any material channel other than the normal map to be sure about the third one):
First issue: It’s too bright. An unmodified normal pixel should be at 0.5, 0.5, 1. Yours is at 0.75, 0.75, 1. I’m unsure how you got there unless you exported it more than once and either performed some math on it or used the wrong color management at some point. Could you tell me about your process so I can pinpoint where it went wrong?

The map looks correct if you switch it to sRGB :stuck_out_tongue: .

I have no idea how you did it, but it seems that somehow you managed to bake an inverse gamma curve into your map? Lol.

I started playing around with nodes recently, so I’m beginner in this area.
Fair point, I removed all textures and other meshes except for main body and its normal map and colour texture (so you could see if normal map does anything). I reduced the file size to 15.8 MB. I can’t reduce it further. I don’t think it’s gigantic file to download now. https://mega.nz/#!vdczTQjZ!4BJcGMyilOcUieGG2nA4wiCgNlWhUyNUsNnZ2tPPvFY

I used this workflow presented in the tutorial https://www.youtube.com/watch?v=0r-cGjVKvGw Blender baked a normal map as you can see and I didn’t mess with any settings that made it brighter than it should be. I don’t know what values you talk about either. I made high poly mesh, then used RetopoFlow Plugin to retopo the model using its mirror modifier. I unwrapped mirrored mesh (hence you see only have half of UV Island) then applied mirror modifier and baked normal map using steps from the tutorial I linked above.

Huh, everyone sets normal map as non-colour data… Maybe I messed it up and it’s suppoused to be sRGB.

I don’t know either xD I followed steps of this tutorial to bake a normal map https://www.youtube.com/watch?v=0r-cGjVKvGw

No, no. It’s correct to set it to non-color and everybody doing it isn’t wrong.

Except in case of your textures you somehow managed to bake them in a way where they have the color space transformation pre-applied. This is not a good thing. Re-bake them so that they’re normal (no pun intended).

I don’t know how you did it, so I can’t help you correct the mistake, but at least you know what to look for. An ordinary normal map should be filled predominantly with this color, except on bumps:

I see, thanks.

I made a high poly mesh, then used RetopoFlow Plugin to retopo the model using its mirror modifier. I unwrapped mirrored mesh (hence you see only have half of UV Island) then applied mirror modifier and baked normal map using steps from the tutorial I linked above. I didn’t do anything else.

For example, claws’ normal map was baked like this as well:
https://imgur.com/a/mkaiqW8

When I used dedicated softwere, xNormal to bake a normal map it looked like this (Of course it needed more time to calculate rays so it wouldn’t have such artifacts):
https://imgur.com/x1Jq8ns

This BlenderGuru tutorial is far from enough to learn how to bake a normal map on a mirrored character. In fact it’s not enough for pretty much anything a little more complex than an anvil (which is not very hard to get).
For the brightness issue, all I can recommend is start again from the default settings.
For the seam issues, maybe this video can help: https://youtu.be/rGYdjdLIMsQ (you don’t need to triangulate your mesh unless you work on multiple 3D apps though)

But you need to fix the brightness issue before anything else because it orients all your normals sideways.

Did you look at the blend file? You mentioned other issues.
Blender did bake normal map with such brightness by default as you can see on claw normal map (Bake doesn’t even have brightness settings). I literarly didn’t touch anything that wasn’t mentioned in that tutorial. I prefered to use that method because xNormals create lots of artificats during baking.

I’ll try the little fix the guy suggested in the video you linked. So I’d apply mirror modifier, offset half of UVs and then try to bake a normal map.

When saving the image right after baking, was Save as Render enabled ? (it should not be)
Yes I looked at the file but didn’t pinpoint the brightness issue yet.

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Owwww crap, that would explain problems I had some time ago! Thanks.

I can’t remember. What’s the default option? If it’s “Save as Render” then yes, it was enabled.
Alright, at least I’ll remeber to keep Save as Render option toggled off.

the default is off
If you still have this issue, I may need a blend file with your configuration right before baking (because the files you provided are switched to Eevee), with a part of your high poly mesh (e.g. just the head) and your userpref.blend file, so I can hopefully reproduce your issue.

So, just to be clear, you made sure to set your image to Non-Color before baking, right?
Because if you do it after it’s too late.