Directional lights cause weird square lighting glitches

ned_poreyra

I'm learning to light a basic scene in Unreal and I'm getting some weird light glitches from directional lights.

It's better visible when I remove lights one by one.

Point light doesn't cause such glitches.

Actually I made a scene with just one directional light and a cube and the glitches were still appearing. So it's either an inherent "quality" of directional lights in UE4 or I'm doing something wrong on an even more basic level.

Obscura

Adjust the shadow bias parameter.

ned_poreyra

I couldn't find this parameter anywhere, but when I closed the project and later opened it again, the glitches were just gone.

What a cool software.

Obscura

What you were seeing is called shadow acne:
https://www.google.rs/search?q=shadow+acne&client=opera&hs=Ig&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjlxIXHoqHlAhUMEpoKHUBjAYMQ_AUIESgB&biw=1880&bih=976

The shadow bias parameter can be found in the properties of the light source, on the details panel. In case you or someone else would run into this in the future.

ned_poreyra

Are you sure about the shadow bias? The only shadow-related parameters I can find are Shadow Exponent and Distance Field Shadows.

-Edit-

Ok, I found it. Under "Light" there is a little white downward-facing arrow that hides advanced settings.

Obscura

Yep... You could also use the search bar there to find hiding parameters.