Lumen’s rebound error problem, I have sent you the project file by private message.
I would like to know if fixes are planned for bad shadows with Foliage Nanite and Ray Tracing Shadows. For the shadows cast on the ground I don’t think there is a solution for the moment, I tried with Fallback Error 0.0 but the crown of the tree loses all the brightness and the scene becomes heavy.
For bad shadows on the trunk I tried with the commands:
r.Raytracing.Shadows.EnableTwoSidedGeometry 0 but is ineffective
r.RayTracing.NormalBias 5 solves shadows on the trunk but removes shadows on grass leaves.
The scene without Ray Tracing Shadows is clearly much slower.
Nanite and Ray Tracing Shadows
Nanite and NO Ray Tracing Shadows
Nanite and Ray Tracing Shadows
Nanite and Ray Tracing Shadows + Fallback Error 0
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Hi, I’ve tried opening Sci_Fi_City, Sci_Fi_City_Rain_Day and Sci_Fi_City_Rain_Day_Combine flying around, waiting a bit and can’t reproduce it. Maybe it’s something specific to 3090, as I don’t have a 3090 at the moment.
As a workaround for your normal issue you could use the Ray Tracing Quality Switch Replace node to remove normals only from Lumen. looking at the density of your geometry it shouldn’t really change much.
It isn’t, I’ve had this issue on my 3070 using megascans quarry meshes. It always seems to be pockets of red light specifically, I seen it manifest as any other color.
Sadly I don’t have a scene to reproduce it as I ended up rearranging the scene until it went away.
Yeah, you are right. Finally I found the bug and fixed it for 5.1. Thanks everyone for help.
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put the r.Lumen.ScreenProbeGather.DownsampleFactor 10 and it will go away when rendering
The deadline for fixing visual issues for 5.1 has now passed. Thanks everyone for your help testing Lumen. We fixed Lumen on AMD thanks to @Yaeko, phantom red lights thanks to @Bio_Weapon, enabled ‘Affect Distance Field Lighting’ by default on FoliageType thanks to @_ScansLibrary (one less step to get Lumen + painted foliage working).
We’ll keep working on Lumen and investigating bugs reported here, but those fixes will go in a later release.
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That’s an RT shadows issue and this is the Lumen thread.
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Great to know, thanks!
Just for curiosity: Lumen changes are only made during the first update of the Preview versions?
Thank you (and the Lumen team) for being “accessible” to us in the forums, it really makes things a lot easier.
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I’m getting this in 5.1 Preview 2 and UE5 Main (Built from source on October 23rd). I’m on an RTX 2060 Super if that helps.
I’m sure it will, but we need the quality. Lumen wont give you good AO on complex shapes. Even with the lumen scene looking almost perfect the screentraces will introduce bright spots below meshes.
We are getting these chopped up reflections using lumen. The first image is using raytraced reflections. The mesh is shaded smooth and the GI looks perfect. Increasing the polycount just makes the fragmentation worse.
Also the view distance in the reflections is not high enough for our scene. I was not able to fix this with the lumen settings in the ppv and I couldnt find a console command controlling this.
This happens on both translucent and opaque materials.
Edit: We are using high precision normals and tried different meshes and materials. We also tested disabling hardware raytracing.
This is interesting, as RT reflections don’t support occlusion/GI in the same way lumen can. That fragmentation looks like a shadowing issue more than a GI issue, so I’d ask what your shadowing solution/CVars are first.
Lumen viewdistance can be maxed to 800 meters in the PPV, but beyond that, you’ll have to set up ‘far field’, an HLOD system that lets lumen do long-distance traces. It’s a bit of a hassle at first, but way cheaper than standalone RT when it comes to supporting larger view distances at detial.
Will Lumen ever be enabled for secondary views, namely SceneCaptures? I can understand disabling it given the cost, however I’ve used SceneCaptureCube’s in the past in order to generate static cubemaps in-editor to be used for particular effects, such as for fake interior cubemapping. Basically, effects that only need to be generate one frame and then get saved out to a texture.
It would be nice to be able to do this with Lumen.
Hey! We are rendering a cinematic so performance doesnt matter. But thanks, I will check out far field and see if it fixes our issues.
Raytraced reflections dont show any lumen GI, thats true. But you will see direct lighting and thats actually looking good enough in most other shots.
The chopped reflection issue has nothing to do with shadows. We are doing a lot of testing with this project, switching between raytraced shadows and VSMs. (Btw this is UE5.1 Preview 2.)
The reflection gets chopped based on the mesh geometry. I tried different meshes coming from different sources but they all have the same issue.
If it solves your use cases, then by all means, proceed with it. Just out of curiosity, what are your PPV settings? This is partly for my own curiosity, I’ve been running lumen through some stress-tests and I’ve yet to encounter anything like this before.
I believe the lumen team actually added some sort of support for orthagonal cameras (could be wrong/misinterpreting the github commits), but I’d be curious how well it would work. Lumen leans heavily on temporal accumulation and screen-space effects, so cube maps might have unsightly seams.
Alternatively, you could construct your interior scene in a new level, and run GPU lightmass on that very fast scene to get clean, view-independent GI, SceneCapture it, and use it in your level.
This is what I’ve been doing, it works fine but it’s an issue of dealing with the lightmap UVs because I don’t need/want them aside from baking the interior cubemap lighting, so I have to remember to delete the lightmap UV channels afterward.
Can anyone tell me if it is worthwhile to try to minimize the number of cards being generated?
I model my modular environment pieces as solid, closed chunks. I developed this habit in UE4 because I found it generated better mesh distance fields and helped manage light leaking from cascaded shadowmaps.
I do this even on meshes only intended to be viewed from one side, so it only makes sense to capture the surface from that side. Unfortunately if I set the maximum card count to 1, it picks the wrong side to generate a card for:
I need at least 2 cards to ensure the correct side has a generated card. I’d like to know if there’s any meaningful performance to be gained by modeling my meshes as single sided, in hopes that I can reliably capture it using only one card.