Strange 'Vignette type' effect due to Directional Lighting

[OC-Infinity]

Hello,

I’m quite new to UE5 and am using UE5.0.3 (need to use this version for university), I have a scene set up with objects made in blender with baked textures. I have a strange ‘halo like’ effect around the borders of the viewport & Play Viewport, the vignette style halo only shows when I look at the mesh I made. This effect only happens when I have scene lit with Directional Lighting, when I use a spot light / point light etc, this doesn’t happen.

Plz help , I’m using 3060rtx, got all the raytracing turned on etc

(looking at wall close-up Viewport)

(Looking at hole at top of cave Viewport)

(Play Viewport, as you can see halo on the edges & slight halo glow around character)

(Glow around character again & walls Play Viewport)

(Play Viewport Scene lit by singular Point Light, as you can see, no halo, no edge glow)

(Viewport with Directional light set to 'Static, instead of Movable - edge effect even more prominent)

Anyone know what’s going on? Plz help

[EliasWick]

I have experienced this as well! I am not sure what it is due to, but try to disable global illumination to see if it helps. (Obviously not a solution, but it’s a good indicator on why it happens.)

[Arkiras]

Post the Lumen debug views

[OC-Infinity]

Here it is,

Standard View

Lumen Debug View

also, I swapped out the ground floor and there’s a more noticable ‘ghosting’ effect going on

(tried different Anti-Aliasing Methods in the Rendering inside of Project Settings, but none made a difference to that ghosting effect.

[OC-Infinity]

yeah just gave it a go, didn’t make any difference :S

[Arkiras]

Switching Global Illumination method in your post process volume to “None” made no difference?

[Arkiras]

@OC-Infinity

Lumen Debug View

You have quite a lot of light leaking…

What does the exterior look like? Is this a paper thin mesh? One sided? Two-sided?

[OC-Infinity]

sorry didn’t realize it was in post processing volume (haven’t bene using UE5 for long) typed global illumination in project settings & ticked & unticked whatever there was, this is with it off:

also, yes … literally paper thin, they’re just displaced planes with ‘Double Sided Geometry’ & ‘Two Sided’ material enabled.

Outside:

The cave walls extend INTO the ground plane (so don’t understand why there is light bleeding in from the bottom…

[Arkiras]

You can try a couple things, I don’t know if they’ll help.

1. Change your shadow method in the project settings to virtual shadowmaps (or disable raytraced shadows in your directional light)
2. Surround your meshes with rescaled cubes to act as light blockers, instead of relying on two-sided geometry to shadow the interior.

[OC-Infinity]

So the two options in step one you outlined just altered how the shadows on the wall behaved, but didn’t affect the white ‘ghosting’ type effect on the boarders of the viewport.

second option, also didn’t change anything unfortunately

(that wall) can still see it on left side of viewport

[Arkiras]

Yeah… so… this appears to be a problem with using Lumen with Hardware Raytracing on Two-Sided materials. I’m not sure why it behaves this way, but you can fix it by either disabling two-sided in your material or by not using hardware raytracing with Lumen

[Arkiras]

@OC-Infinity

second option, also didn’t change anything unfortunately

It works. You didn’t disable two-sided in your material.

[OC-Infinity]

Yep! … removed all the ‘two sided’ materials and the problem is gone… Thank you for your help mate…

Any recommendations on which solution is more beneficial? whether I just turn off hardware ray tracing, or turn off double sided? (cave will only be seen from the inside), I’ll play around with both but a more experienced opinion is always appreciated!

[Arkiras]

I would disable the two-sided material. It adds a little bit of extra work because you need to set up light blockers around the environment, but it means you can still use hardware raytracing on systems able to run it, which will provide much nicer reflections if you decide to do something like add water to the cave later on.

[OC-Infinity]

Only downside to the non-double sided, is that it doesn’t show the shadows of the wall bump :S but it is a drastic improvement over the ghosting…

There is one more solution that I ended up trying which… gives the best result, actually making a double-sided mesh of the wall hah…

the thick wall doesn’t have ghosting problems, nor does it need to have double sided material, and keep the shadows.

thanks so much for your help though, definitely a good thing to know moving forward on how the materials & raytracing affects the mesh!

[BananableOffense]

You can set the mesh to cast shadows as two-sided even if the material itself isn’t. I haven’t tested if this will reintroduce the issue or not.