That would be a really interesting approach honestly. Would that be a sort of per-light depth-peeling, like used in some IOT methods?
And I think that might be interesting, what’s cool is that NVRTX handles both reflective and refractive caustics, including caustics cast by area light sources. I think that would be somewhat complex to implement in real-time, given the amount of scene data you’d need to maintain (and Yaeko’s point amount data accumulation rings true). That being said, they have a method of implementing caustics on water from a directional light that uses the mesh itself to guide rays (I’m paraphrasing and simplifying a lot here), and that could be a very useful feature to improve the realism of shallow water, although I know Epic already has an in-house caustics system (unsure if real-time or baked though).
I honestly think this is a really good discussion to have, as caustics is one of those phenomena that is generally pretty hard to do in real-time (although there are many ways to fake it with light functions and trickery).
Besides, caustics are a form of global illumination/reflection (Diffuse-specular-diffuse). Lumen’s temporal accumulation wouldn’t work well with caustics potentially, but since lumen already has a method of handling dynamic shadowing, I’d imagine there’d be some way to work in rapidly-changing lighting conditions (especially since caustics didn’t seem to add much to GI in my testing).
Water caustics seem to be more of a solved problem than mesh caustics (or colored shadows), as the rapidly-changing lighting of water gives some room to ‘fudge’ the accuracy of said caustics. I could go without mesh caustics in real-time, but I think reactive water caustics could add a lot to scene visuals.
Hello!
I have the visual problems with Lumen when using the latest 5.0 in GitHub when start the “Stack O Bot” project.
(Launcher version of UE5 EA2 is ok)
Also the Audio components is broken too.
Maybe I forgot to build anything?
Thank you in advance for advise!
I’ve experienced this same bug before. The skylight image gets corrupted somehow (I’ve had difficultly replicating it, it seems rather inconsistent). It causes immensely strange light patterns that seem to be coming from a corrupted texture, and I’ve found recapturing or changing the cubemap texture seems to alleviate it. Unsure what to do about Real-time capture, but I haven’t encountered this bug in any engine version after EA2.
Can anyone who uses UE5 main confirm if Lumen can do reflections on translucent surfaces? If it at least works like regular reflections where lumen scene is seen in reflection.
We do have Lumen reflections on translucent surfaces, but they are limited to being very glossy, they don’t look like glass. At least they don’t glow with the skylight from outside like in Early Access. It’s something we hope to improve after 5.0 is released.
Started testing preview 1. Getting artifacts instead of proper GI in reflections when switching the ray lighting mode to “hit lighting for reflections”.
Thanks for that report. There are a bunch of issues with Hit Lighting that should be fixed in the next preview, including that one. Let us know what else you find.
So reflections on translucency are a little better, the material doesn’t glow however I still see sun disk in reflection even though it should be shadowed by ceiling/roof
