I noticed this too. Lumen doesn’t work well with high res tiled rendering.
I have the same Issue 
Seems like the early access was better than the final release
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From a capabilities standpoint, perhaps, they did cut some stuff they were experimenting with in EA. From a performance standpoint? I am personally seeing 60FPS scenes that barely run at 10FPS in EA , especially in scenes with foliage or large amounts of alpha masking in general. I think 5.1 will deliver on many of the desired features, including Nanite support for WPO, PDO, and masked materials, lumen reflections on translucency and SLW, and probably some of the stranger use-case items like high-res archviz and stylized rendering. Just a speculation, but their Github page is very telling for what items are in active development or not.
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Will hit lighting/material evaluation be added back to radiance cache and screen-probe gather? Seems the issue with foliage over occlusion is that masked materials are treated as fully opaque (in RT mode)
I thought the foliage over-occlusion problem was solved, it might have been one of the features that didn’t make the cut however. I know enhanced support for masked and translucent materials should be coming in 5.1 (whenever that might be, perhaps late summer or fall if the UE4 schedule holds). It worked on the last UE5_main build I had, but solving foliage over-occlusion came at an extra Lumen cost.
New feature in Lumen, UE5_main: alpha masking is finally supported in the surface cache, which should go a big way to solving foliage over-occlusion on a lesser performance cost. This personally solves a lot of strange foliage and over-occlusion issues I was running into with legacy elements that had alpha masks instead of complete models.
By the way, for people whose content is broken with loss of tesselation, I just realized UE5 has a feature that can help, albiet with a bit of extra effort: UE5 has a modeling tools plugin that dropped a bit ago (never played around with it much myself), but it has a subdivision surface modifier that can give your meshes back geometric resolution they lost without having to re-export and import them.
It took me less than five minutes to figure out how to use that system after booting up the mesh editing tools. If the mesh has Nanite enabled then geometric resolution doesn’t matter much (side from disk space), so it’s a pretty good system all-in.
This seems to be only enabled on reflections for now but you can enable it in radiance cache, screen-probe gather and direct lighting yourself by adding ‘Context.bAlphaMasking = true;’ below the FRayTracedLightingContext Context in each shader. It does come at a small performance cost but it fixes the foliage overocclusion problems I was having.
Sorry but claiming that rudimentary modeling toolset with displace operation is a solution for removal of dynamic, view based tessellation is a bit preposterous.
That’s like claiming Lightmass is all-in a good system for replacing Lumen.
That’s good to know, thanks for telling me about it. I’m curious as to the implications of the github update then, what their they mean by the new alpha masking support (I was just guessing from the update descriptor, didn’t actually dive into the code). Thanks for the tip on solving foliage overocclusion, I’ve had some meshes that have been behaving weirdly and this is really useful.
It’s solved all of my use-cases. UE5 modeling tools, especially early ones, are obviously not of the same caliber as dedicated content-creation software, but it’s been really useful to me.
And that depends! Lightmass is good for lower performance targets, and lumen can facilitate excellent dynamic quality. It’s all a matter of scalability and feature sets. Lumen can’t currently support colored shadows, which lightmass can, so it’s a feature trade-off.
I just noticed, that Point Lights with a Length still dont work properly in Lumen, just as half a year ago:
In both images, it is clearly visible that GI is primarily working around the location of the actual light, the center of the laser. (see the Roof)
VERY VERY BAD BUG IN LUMEN
how we can disable skylight cubemap reflection in lumen ?
skylight intensity 1 = good water
skylight intensity 10 = bad reflection on water
blocked all windows
again skylight reflection ?
how we can have skylight reflection in the interior without windows ?
there is not specular parameter in skylight setting
You’re right, it’s not hooked up for some reason. I’ll add that to the list.
Some issues seem to have returned with the UE5.0 full version. @
Very dark undersides of the leaves. You can also see the lumen view.
Sorry for late reply. Unfortunately I introduced some serious artifacts when I added proper support for Two Sided Foliage shading to Lumen (gathering lighting from both sides of the leaf), and I realized it was going to be a large undertaking to fix, and way too risky to try to slip in two days before 5.0 release, so I had to revert it.
That’s what I get for showing results too early =( It’s on the list
I had to revert Lumen supporting Two Sided Foliage as there was a fundamental flaw to my approach that I couldn’t safely fix right before 5.0 release. Sorry for the tease, I should have tested better before showing results.
Hi, this looks like a difference between Virtual Shadow Maps (new default in UE5) and regular Shadow Maps (default in UE4). You can switch back to regular Shadow Maps in the project settings - search Shadow Map Method.
That’s not related to Lumen though, best to ask shadowing questions in another thread.
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This is a bug that made it into release, you can work around with ‘r.Lumen.ScreenProbeGather.IrradianceFormat 0’
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Hi , when I investigated your scenes before this was due to the meshes not being modular enough for Lumen’s Surface Cache to unwrap. Check the Lumen Surface Cache viewmode, if it’s all pink then that’s your problem. From the doc:
Only meshes with simple interiors can be supported — walls, floors, and ceilings should all be separate meshes. Importing an entire room, which includes furniture, in a single mesh is not expected to work with Lumen.
Even if that particular case worked better in Early Access, we’re moving forward with what we have now, which works much better on scenes that were built to Lumen’s content requirements (modularly built).
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No, the distance field implementation in UE5 is improved in a lot of ways:
sparse (only stored around geometry), streamed (with mipmaps), 2x higher resolution by default, 10x faster generation (although mostly canceled out by resolution increase). Better biasing (avoid self intersection on large objects), better representation of thin objects.
DFAO works for large scale occlusion, and with ‘r.AOQuality 1’ you can get the super fast mode that only uses the Global Distance Field. Quality is limited though, as it was targeting last generation consoles.