Bright outline on normal map where 2 surfaces meet... what causes this?

Development Rendering
1

Hey,

Every time i import a normal map into UE4 and apply it to my objects I get this weird outline where differences in normal direction occur. Like the compression is adding Normal directions in there that shouldnt be.

NormalError.JPG

As you can see there is bright line of pixels in the indents of the normal map. This is not present in the normal map itself before I import it into UE4.
This happens on every normal map on every model. the compression method is set to normal map. It’s imported as a normal. map. it has been normalised in photoshop. Even if I use No Compression there are still artifacts there.

Is there something that I am missing? (I don’t remember this ever happening in UE3)
It’s currently making everything look really ugly as I have walls full of this and it’s ‘buzzingwith jaggies’ all over the place.

Any help would be greatly appreciated :slight_smile:

cheers

2

Can you show the actual normal map colors (under debug visualizations is a world normal view mode).

It is probably just interpolation between the opposing values causing a normal that faces perpendicular to the surface at some point, although that point should be much smaller.

I wonder if perhaps your normal map is going into negative Z territory due to the blue channel being way too dark before importing causing a backfacing normal? I have seen the engine do some weird things in that situation since it assumes normals point upwards.