[4.27] Shadow gap when close to ground

Hey there! I have problems with dynamic shadows of a static mesh that is very close to the ground (even intersecting it). There is a small gap that very distracting.


This becomse even more prominent from a distance.


The same problem applies to the landscape


How can I avoid / overcome this? I am a complete noob at lighting…

Thanks and cheers!

Have you tweaked any directional light settings, is it like this with the default settings?

Just double checked and deleted mine to be sure.
Even if I delete everything else (SkyAtmosphere, SkyLight, etc.) and have only the landscape, the brushes, the static mesh (a 1m cube, scaled a bit) and a fresh directional light with movable lighting and a higher than default Dynamic Shadow Distance (think default is 20,000 and I set mine to 100,000) the shading appears like above.

Even at default settings (distance), with a completely fresh Landscape, it appears to some extent. Of course it then fades out when we get to a distance higher than the max Dynamic Shadow Distance (where the shading gap became even more prominent).


How about normals at this mesh? It is very narrow. Do you tried double sided mesh/material?

If it’s a thin mesh, and you increase the max shadow distance, you will get this effect.

Can this be avoided somehow? Some mesh, material or lighting settings?

The normals should not be very special on this one. It is just the basic cube, scaled to be about (8, 2, 70). Could the scale maybe affect the lighting in some way?

The Two Sided option in the material does reduce the gap by quite a bit, especially noticeable at large distances. The gap is still very prominent though, as it basically pops into view when there is such a brightly lit gap between the dark drop shadow and the shaded side of the block.
Thank you for your help!

The UV maps of the objects must be opened properly. Normals should be fine. If the UV ranges are too high, it is normal to get such images again. Or the lightmap resolution may also be low. These are the ones that come to my mind.