Unral Engine 4 - Mirrored UV's, normal map problem.

S@murai

Hello all!

I've created a simple asset with mirror modifier. I wanted to try out if normal map will work... and it does not.
My UV look like this

I've uwraped half of the body and half of rubber belt.

I've set textures in unreal to mirror instead of warp, but it all turn out to look like this


Is there any way to make it work?

Vailias

Normal maps are vector data, so if you're mirroring them you're flipping the vectors.
You could possibly compensate for this by inverting the red and green channels in a shader based on UV coordinates, or you could redo your UV layout to tile rather than mirror.

Bedrock

Try recomputing the tangents inside Unreal 4. You can do that by double clicking the mesh in the content browser, go to build settings, tick "recompute tangents" and click on the "apply changes" button.

dzibarik

Don't forget to add lightmaps or the seam will be visible.