Problems with Lumen UE5 preview

Hi everyone!

I am new to UE and have little experience with it. I have UE5 Preview and I have a scene with a SkyAtmotphere, DirectionalLight, SkyLight and a totally closed room where no light enters.

But it seems that Lumen is not working properly.
I leave two videos so you can see what I mean:
https://youtu.be/i7KNQvZQCWM
https://youtu.be/KdyqIg4lLyU

Why is this error happening, how can I fix it?
The meshes, UVs are created with the UE5 modeling tools, converted to Nanite and assigned a MegaScan material.
The meshes are double-sided and have a lot of thickness

What am I doing wrong?
Greetings and thanks in advance.

Any help or information on this problem?
regards

What does the lumen overview viewmode look like?

Thanks for answering @Arkiras !
This is what it looked like:

I tried to make the walls thicker and the problem has improved, but if you look at the lumen overview it seems that it is not completely corrected yet:

Can anything else be done to completely correct it?

On the other hand, these artifacts always appear on that wall that is seen in the video and they are only corrected if I turn off the DirectionlLight or make sure it does not affect the world:

I have tried creating other Nanite and non-Nanite meshes, I have changed the material parameters, but nothing solves the artifacts.

How can this be fixed?

I… sorry… only español… but i am solve… (lo que te recomiendo es eliminar el objeto complejo de SunSky, y crear los actores simples de DirectionalLight, SkyLight…etc) de esa manera podras usar el comando Ctrl+L para controlar la posicion del Sol del Actor DirectionalLight, tambien te recomiendo utilizar con mas cuidado el Actor de Niebla ya que requiere de mucha mas atencion a sus funciones…) un saludo…

image

1 Like

Hola y gracias por la respuesta.
Las recomendaciones que me indicas no solucionan el problema que comenté. No es problema de la niebla porque si la desactivo o la borro de la escena, el problema persiste.
He probado ha cambiar de material para ver si eso soluciona el problema, pero tampoco.
Francamente no se que más probar. Voy a probar con la Preview 2 que acabo de instalar y ver si soluciona el problema.

This actually seems to be an issue with Virutal Shadowmaps. Reducing the sunlight intensity helps, but doesn’t completely eliminate the light leaking. The only way I have found to solve it is to just switch to regular shadow maps.

2 Likes

Fixed. That was the problem. Thanks so much for the help.
Greetings