It seems to be Anti Alias related.
If I go to Settings> Engine Scalability Settings > Anti-Aliasing and change the level from High to Medium the flickering is only visible when I move the camera.
If I switch up to High the flickering is always viewable.
Also if I switch the Anti-Alias type from Temporal to MSAA or FXAA in Project Settings the flickering is less but doesn’t go away.
The only way I can stop the flicker is if I turn off Anti-Aliasing altogether.
I am using an ExponentialHeightFog actor with a Directional light.
Can anyone suggest further troubleshooting steps?
In case it benefits someone, the issue was my PostProcessVolume set to Infinite Extents.
The problem is, if I disable Infinite Extents, my PPV stops working even though it encompasses my geometry.
When disabling Infinite Extents, what are the Blend Radius and Weight settings at? I think I have encountered the same problem before, and I don’t know how to solve it. It either got solved by something I did which I didn’t know would solve it, or it’s not solved yet (especially could happen again in new projects). The flickering which occurs at almost parallel viewing angles is apparently a common issue. I don’t think the anti-aliasing method is the primary cause of it, though it is involved somehow.
That’s interesting because I’ve seen it referenced as a problem occuring with RT translucency in these forums. But I’ve encountered it without RT translucency and RT disabled.