Lumen HWRT Vs. ReSTIR GI (both have RTXDI) Castle - Unreal Engine 5 NvRTX Branch

[@zakaria20062]

hi , i was amazed by your testing and Rnd , im looking for advice about archviz project real-time for big scale real estate i try only lumen and i fell just to heavy and slow FPS s , what method you think is suited for that ?

[@fabiolives]

@@zakaria20062 Lumen can be great for realtime but it depends on the specs of the PC running it. If this is something that a lower end PC will be running, I would recommend using screen space global illumination. If it was for a render I would suggest Lumen or path tracing. I have had success getting Lumen running well for GPUs down to the 1060, but I would avoid it for anything below that

[@demiurghg]

Ok, now add rapidly changing camera and light conditions and see the changes. Otherwise, static lightmap does the same with no performance cost.

[@fabiolives]

Not even close. Static light maps won’t have the same real time beautiful reflections that this does, although that’s not visible in the video. You’re welcome to use static lighting in your own games though.

[@Ziov1]

Which is best for performance, learning UE5 but planning to use Path tracing with lumen shadows.

[@fabiolives]

I would actually recommend sticking with Lumen in general. ReSTIR looks cool but in most situations it’s not much different than Lumen and runs significantly better. I would say the exception is in areas with lots of reflections or translucency, that’s where ReSTIR shines. Lumen can also scale down to pretty modest hardware with the right tweaks, while ReSTIR pretty much requires a high end PC if you don’t want to rely on frame generation. I don’t like to center my optimization around frame generation so I only really include ReSTIR in games I develop as an extra option, definitely not the main one

[@Ziov1]

@@fabiolives thank you for the great information.

[@fabiolives]

@@Ziov1 absolutely! I love learning about optimization with unreal so you’re always welcome to ask questions