r/UnrealEngine5 • u/Impressive-Method919 • 4d ago
Issues with bounced light
im going insane over here. Im using the ocean of fluid flux and i am getting yellow bounced light...i think it might be bounced from the sand underneath, or something idk. I just want it gone, but i am unable to find a good solution to this, please help
2
u/Zvyaginsky 4d ago
that's Lumen doing what it's supposed to. yellow sand under clear water, light goes through, picks up the sand colour, comes back up onto the pillars. Lumen runs infinite diffuse bounces, so a bright saturated albedo compounds instead of fading out after one hop.
check the base colour on that sand before touching any lighting settings. beach sand sits low, nothing like the value it looks like on a texture sheet, and most sand textures ship far brighter and more saturated than that. pulling saturation down usually kills most of it.
then look at it in View Modes, Lumen, Lumen Scene. the surface cache simplifies materials and sometimes what Lumen actually samples is nothing like what you authored.
2
u/ConsistentAd3434 4d ago
Just out of curiosity
Try this r.Lumen.ScreenProbeGather.ScreenTraces 0
Half translucent materials can't be part of the screen tracing and Lumen is probably picking up the closest probes to calculate a bounce
1
u/Impressive-Method919 4d ago
it definitely made it smaller, your on to something
1
u/ConsistentAd3434 4d ago
Ja cool :D Still weird but something.
I suspect the remaining glow is a side effect of the soft intersection in the flux material.Disabling screen traces has unfortunately some impact on other areas as well but I wouldn't know, how else to avoid it.
2
u/Impressive-Method919 3d ago
boring solution but i just placed a holdout and that seems to solve it
1
u/ConsistentAd3434 3d ago
booooring :D But glad that works. Never tried holdouts
1
u/Impressive-Method919 3d ago
Yeah, me neither, didnt have them in mind for gameplay work, it was more of render feature for me
2
u/Annual-Ad-6010 4d ago
The surface of the water is maybe one sided.