Flicker on Architecural parallel lines

Hello, I have a problem with some vertical meshes that are close to each other that are causing flickering or moire (in french).
When I’m going far of the meshes I have more and more flicker on the meshes and on their shadows.
I think this is because there is less than 1 pixel between meshes, but I didn’t find the soluce.
If anyone has an idea, it will be welcome.

It can be caused by out of bounds pixels. Every mesh has bounds (go to Show > Advanced > Bounds to display in viewport), and if any pixels of the mesh are outside / extending beyond the mesh, it can produce problems. One way to check is go to Show > Visualize > Out of Bounds Pixels, and if there’s yellow / blue / white highlighting on the mesh, then it has out of bounds pixels there. Here’s a link:

Another possibility is occlusion culling at those zoom levels with the camera, or due to camera speed being slower than the occlusion culling completing for those meshes. Precomputed visibility settings and any other occlusion culling parameters could be tweaked to set it right.

Hello and I really thank you for taking time to answer.

Apparently, there are no “out of bounds pixels” error
I tried to adjust some parameters or extend the bound size for “occlusion culling” , but nothing changed

So, I’ve started a new project to test the problem

I just create a new project with the preset for architecture, enginering and Construction named “Archvis” with raytracing enabled

I drop the cube preset in the scene, duplicate the shape and the flickering artefact are present on the meshs and there is also problems on the shadows

Maybe, it has something with “BaseScalability.ini” or “DefaultEngine.ini” files?

I also tried to adjust the temporal motion blur that should attenuate the problem, but it doesn’t seems to work for this

296248-screenshot00000.png

I’m working on UE4.24.2 with rtx 2080

If you want to take a look, there is a link to my project :

[FlickerTest][2]

Hi i have same problem with vertical meshes that are close to each other. Do u have any solution anyone??

I’ve encountered this in a simple project too. It’s interesting though because it has only occurred with meshes that I make translucent or transparent, such as using glass material from the Megascans pack for glass. I made a glass material, that was not Megascans, and it did the same. So, I moved each mesh away from the adjacent one by 1 pixel, and it stopped flickering. I also adjusted the Z location of the meshes to be 1 pixel above their previous location, which I think is 1 pixel above the floor, and that worked too to remove flickering from the top / bottom of meshes. I’ve read the term ‘z-fighting’ in regard to flickering or artefacts that contain a graphic motion or change. It’s one term to use when searching the forums or a search engine for solutions / workarounds. I’ll have a look at the test project and try some things to see how to solve it.

I wasn’t sure if it would be “out of bounds pixels” as it would seem to be more obvious that’s the issue if it was the problem. However, it could be not very noticeable that it’s “out of bounds pixels” with regard to lighting. Read the page on “out of bounds pixels” and you’ll understand what I’m talking about, I think.

Keep the thread here posted with updates on the issue, whether it was solved, and how…and I’ll do so too. It’s a somewhat common problem in Unreal Engine, from what I’ve seen in the forums.