Troubles in Normal map from XNormal

Morgul

Hi all! I baked normal map in xNormal and I've got this strange bug on it. Strange steps. It looks like in was converted many times - decreased and then increased its size... But it just came from xNormal. Models are ok, no bugs, good topology. Who knows - what is this and how to correct this bug.

McGreed

Could it be that your green channel is inverted? I noticed that I had this issue when I took a model from 3DS max and baked it in xNormal and then pulled it into Unreal. Could be your normals are pushing the wrong way, which is why it looks wrong. Another look of the area from a bit more indirect view might help.

huffer

It's just color banding due to the limitation of saving an 8-bit map. One fix is using dithering like the 3dsmax baker does, but it's not available in xnormal, another is saving a 16-bit tiff from xnormal, and then converting to 8-bit in Photoshop.

This is generally not a problem, it won't be too visible with textures and everything. It's more of an issue if your final surface is very reflective, but in that case, even baking 16-bit or using dithering will be visible, so it might be better to use a solid 128,128,255 there - avoid baking those parts and use geometry.

Morgul

MCGREED - thanks for advice, but model and green channel all ok.
HUFFER - Thanks, I suppose, you right, I try to bake in 3ds max and I try to save in 16-bit tiff. And yes - It is not so visible with other textures.

kodde

Is this uncompressed? If it's DXT1 DDS then DXT5_NM could give you less banding. Another idea would be to eliminate the need for that big gradient to being with, i.e. have a look at those vertex normals. Given that both the lowpoly and highpoly feature flat surfaces at this area?

Morgul

it is not compressed at all, but I'll try DXT5. All normals is okey in highpoly and lowpoly models, thats the problem)

ZacD

You can reduce the banding by playing with the vertex normals of the low poly model. Face weighted normals can reduce gradients in your normal map and reduce the banding that you see here.