Using Anti-aliasing in movie render queue causing lumen artifacts/instability

Development Cinematics & Media
, , ,
1

Hey everyone,

I’ve been trying for a few days now to render quite a complex scene in UE5, but when using the movie render queue, with antialiasing on, i’ve not been able to get the scene to render without lots of flickering with lumen.

To test whether it’s the scene or not, i’ve set up a very basic scene to reproduce the problem. I’ve attached a two video files to this to show the problem.


I’ve tried lots of settings but here are all the project settings and some of the render cvars i’ve tried, but nothing has resolved the issue as of yet.

Project Settings

Lumen Global Illumination
Hardware Raytracing (tried software raytracing too)
Ray lighting mode - Surface cache
Nanite enabled (also tried without)
shadow map method - Shadow maps
Reflection method - Raytracing (also tried lumen)

PP settings

Lumen Scene Lighting Quality 4
Lumen Scene Detail 4
Final Gather Quality 4
Lumen Scene Lighting Update Speed 4
Final Gather Update Speed 4
Raytraced reflections (also tried lumen reflections)

Light settings

Ray traced shadows enabled
Ray traced samples 8
Indirect lighting intensity 1

Render CVars

r.DepthOfFieldQuality 4.0
r.streaming.PoolSize 8000
r.MotionBlurSeparable 1.0
r.Lumen.Reflections.HierarchicalScreenTraces.MaxIterations 4.0
r.Lumen.ScreenProbeGather.DownsampleFactor 8.0
r.Lumen.ScreenProbeGather.TracingOctahedronResolution 16.0
r.Lumen.ScreenProbeGather.FullResolutionJitterWidth 0.5
r.Lumen.ScreenProbeGather.ScreenTraces 0
r.Lumen.Reflections.ScreenTraces 0

AA MRQ settings (Tried almost every combination)

Spatial 1
Temporal 64
Override anti-aliasing x
Anti-aliasing method - None
Render warm up frames x
Render warm up frames 4
Engine warm up frames 64

Is there any way to resolve this? Or is it simply just a limitation for now?

I have had to create a hacky solution, where i’ve rendered one pass with AA and one without and masked off the problem areas, but this isn’t a good solution in production.

Also, this problem is happening in both 5.0.3 and 5.1.0 preview-2 versions.

I’ve seen a few forum posts on different sites with people struggling with the same thing, so hoping that there will be a way to resolve this so other people can fix it too.

Here is a video of the main scene i’ve been trying to render, with the artifacts very visible in the background.

Thanks!
Joe

2 Likes
2

I have had the same problem as you ever sense 5 came out. I have tried everything i can think of to try and fix the lumen flicker, instability when using temporal AA settings in render que. Its really annoying. I hope someone has an answer.

3

I am having the exact same problem as you, and is only happening (or at least more noticeable) when the camera is doing a travelling. I was only able to remove completetly this issue, doing the zoom by animating the FOV, instead of actually moving the camera.

It’s not actually a solution, but at least work.

Besides that, I have been testing it and found that reducing the RelativeDepthThickness value of the ScreenProbes (default value: 0.02) reduces the impact of this Lumen Flickering issue.

I have this Cvar in my MRQ:

r.Lumen.ScreenProbeGather.ScreenTraces.HZBTraversal.RelativeDepthThickness 0.005

Notice that it will also reduce the impact of your GI.

If you found any solution to this problem, please share it, because I am a little desperate too :sweat_smile:

6 Likes
4

having the same issue, going to try the camera workaround on your post

5

I use the same command but with 0.0001 value, i don’t know what it did but it solved the the shadow flickering problem (my cam is moving and using a veri narrow FOV)

1 Like
6

Weeks with the same problem and this work for me.
Thanks!

7

Same problem in 5.3 lol, amazing how none of these big UE YouTubers ever have these issues but it is present on literally everything I work on, with NO fix at all

1 Like
8

I had very similar issues. With lots of flickering from self illuminated materials even with settings cranked up. I just turned on antialiasing - Temporal Super Resolution and left it on default. Animation was super quick and smooth. Not sure if it’s just blurring stuff behind the scenes but looked pretty good to my old eyes!

9

Hey, I had the same problem for weeks, I noticed that it could come from Virtual shadow maps, I changed in the -Project settings - Rendering - Shadow Map Method : Virtual Shadow Maps to Shadow Maps.
This changed the rendering (in shadow) a little, but it may be a good way of finding a solution to this problem. I’ll let you know if I find a way to correct this problem with virtual shadows enable.