Eevee Splitting Shadows - Sun

Hey there,

I had a scout around, but couldn’t find another post on this topic which seems unlikely. So sorry if this is a repeated question.

Anyhoo… Anyone know of a method for stopping the shadows diverging at the interior angle of an object like a perimeter wall… see below:

This appears to only happen with a Sun light source, and whilst I can figure out what is happening with the render, what I don’t know is how to fix it (other than the obvious of using a different type of light source).

I can’t be the first person to have come across this, there must be a good work around. If anyone has one I would be most grateful, this is driving me nuts!

Thanks in advance!

How did you model the wall?
I just did a quick workup, and I can not get the same results.
I ask because it looks like a mesh problem.

Hmmmm…

How odd the wall itself is totally bog standard, just a line which has been extruded twice. The only vaguely unusual thing is I have an ‘inverse-hull’ solidify modifier on it, but I’ve already tried turning that off.

I’ve had a quick check, no duplicate vertexes, no non-manifold geometry, all normals out

It’s not something funky going on with the shader either as I get the exact same split from a standard white diffuse.

All very odd… I’ll try rebuilding the wall later and see if I get the same result.

Ok this is just weird… Could anyone explain what is happening here?

I added a new large plane beneath the original model in to test whether the ground was the problem rather than the wall, and the shadows fixed themselves…

… but I haven’t a clue why.

Anyway I have my workaround… just wish I knew what was going on mechanically.

I’ve traditionally used Cycles over Eevee so is this some sort of quirk with this engine?