I am wondering if there is any way at all to have SOME lights affect Lumen and others not.
I have found even with UE5.2 Lumen cost is very high in my scene and I think I could fix this if my flashlight did not affect Lumen and other lights would.
I know I can just turn Lumen off in the PPV, but I would like to have lights I can toggle on/off that would have GI from Lumen, but my flashlight doesn’t need it.
It is literally the difference of 20FPS on a 3090, so if I could get that FPS back for most of the time when running around with my flashlight and only use Lumen for the lights that matter, that would be awesome.
20fps seems alot for a simple spot light especially on your 3090. Do you have hardware raytracing enabled? Obviously ray traced scenes are going to be heavier on the GPU.
Another thing to try is in the project settings , try changing using Virtual Shadow Maps to just Shadow Maps. And disable Temporal Super Rwsolution in the project settings also.
Set the indirect light intensity to 0. This will remove it from the Lumen Scene but it may still be picked up by screen traces. I doubt this will actually improve performance though.
Have you actually profiled your scene to figure out where the cost is? Or are you just guessing its lumen because the FPS is higher when the light is off? There are costs associated with spotlights that are not lumen related, such as shadows, direct lighting, light functions