How do i update an unreal engine 4 level to perform well with ue5 nanite and lumen?

Development Rendering
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Were your lights dynamic in ue4 or static and baked?

There seems to be a lot of people saying the same thing - lights slow down lumen…

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stat and baked of course… im trying to go away from static and make a fully dynamic lit level.

Also its not a lumen issue. This happens with lumen disabled. I literally disabled all GI and reflections to test with no improvement to fps or the shadows.

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Is there any kind of culling for these lights or disabling shadow casting from a distance? Is there a way to optimize the shadow casting?

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Yes, those MaxDrawDistance and MaxDistanceFadeRange settings I mentioned earlier for culling - and move as many over to just being “emissive” materials - and pooling the same lights over…

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emissive looks like crap

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is there a way to make it so shadows only cast from a certain range then dont from further away?

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There are just the settings in the light details panel. I don’t think they affect the distance in the VSM though.

I was wondering what the Matrix City demo does - it looks like there are a lot of lights in there - so I loaded it up and had a look - it’s only using 1 directional light, 1 sky light and emissive for the rest.

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In the docs they state:

The City Sample is being lit by only Directional Light, Sky Light, and Emissive Materials from surfaces.

I’m going to try and do the same thing for my game.

Out of interest, I found this document which gives some interesting ideas too (not UE targeted):

http://newq.net/dl/pub/MoreEfficientClusteredShadowsPreprint.pdf

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i will say with “stat unit”… the draw is like 70-90 ms with the lights.

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Check out this video… this is the light overlap and it doesnt make sense… most levels its blue… this one has an animated strobe effect over the entire scene that makes it red… no idea what this is … a bug? In fact this same effect happens even when i delete every light in the level… leaving it midway overlap in green isntead of good dark blue…

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holy crap i think i found part of the problem… somehow i guess fire emitters were causing it… which is strange… but deleting those which helped.

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