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Ray traced reflected light doesn't work

Suppose you have a light source, such as a flash light and you shine it at a perfectly mirrored surface such as a bathroom mirror. The light emitted by the flashlight should hit the surface of the mirror and then bounce to hit another object which then gets illuminated by the light photons.

I’m currently using UE4.23 and I have a narrow spot light aiming down 45 degrees at a plane with a material which is a perfect mirror. However, I don’t see the resulting reflection on the adjacent wall. I have turned on ray traced reflections and ray traced GI, but no luck. Is this something that isn’t available yet?

I got the same problem in UE4.25. I tried to adjust the number of bounces in postprocessing volume and it does not work. Winder if anybody know the fix?

That effect is reflective caustics, and that’s not a current feature of real time ray tracing.

Thanks. Good to know.

actually it is avaliable via nvidia

Maybe, but most people do not use NVidia branch. So unless they do integrate this into the main branch, that everyone gets from Epic, then it basically is not existent and not working for many people.

That´s the big problem, if every company develops it´s very own version with unique features - a very large number of people will not get access to those features until they find their way into the version, that everyone can download from Epics Launcher.

Edit: Darn, Nvidia also got absorption working… great… when will they integrate this in the main branch?