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Pre computed Lighting for large city sized level in 4.3

We have been looking at how we should setup the lighting for our city level in Submerged.

The City is very large and has many streaming sub levels and a Dynamic Time of Day. It uses a Movable Directional Light as the primary light source. Rebuilding light maps takes a very long time and seems to have a very limited impact on the visual quality. just some very subtle ambient occlusion baked into the maps form the skylight.

We have tried to change to “force no pre-computed lighting” but this seems to have some adverse effects on the creation of the cubemap probes? and the level doesn’t look right.

My question is: With 4.3 and the new Distance Field AO, would there be any need to have pre computed lightmaps at all?

Cheers

Andrew

Did you turn on LPV? https://wiki.unrealengine.com/Light_Propagation_Volumes_GI

Also as far as I know LPV doesn’t work with Skylights as of yet, I’m not sure of the crooks if it all yet as we only moved to UE4 yesterday although on the list to do is either improve the current system or migrate our LPV solution into the engine.

We are putting together a 24KM scene, lightmass importance volumes cover building interiors well. But seems to have little visual impact on anything else, also it drastically speeds up workflow using LPV so I’ll be glad when we get a completed fully dynamic system implemented one way or another.

You can’t use precomputed lighting if your main directional light is dynamic

Well you can, it is just your Ambient lighting that gets baked into the lightmaps not the directional component…

I have a (somewhat) related follow up question if someone from the engine team can answer it?

How does the lighting work on LOD levels using the World Composition Tool? Can I have completely overlapping levels that are 2 different LOD levels and have the lighting bake cleanly on both (i.e. not cast shadows over each other?)

cheers

Andrew
Uppercut Games

The lighting won’t be correct