What is this graphical "phenomenon" or "artifact" called?

When i set the game to overall medium settings with effects, shadows and AA whatsoever, i encounter this "phenomenon" like on the picture, attached to this post, and i'm interested, what this is?

Also encountered this in other games like Witcher 3, when lowering settings for testing purposes, but never asked myself, what this is. (So i don't think, it's an issue with ACC )

Can anyone tell me, what is happening there, what kind of "artifact" this is, and if there is a way to weaken it effectively?

It's heavily visible in showroom, but not that much, while driving on track.^^

It seems kinda blurry here, in "reality" it looks more kind of a grid of many many little dots, which are supposed to show "shadowing" or something.

 

It's not obvious from your small screenshot which "phenomenon" you are talking about. At least i don't see it.

 

Ambient occlusion ?

 

Dithering?

 

it´s a common problem with Unreal Engine 4, at least i see this in many projects i work on the engine and games using the engine too, i think it has something to do with blur/shadows/reflections(screen space reflections), it´s very ugly, you can see this granulated/dithering effects on mirrors and the screens on the cars on ACC too(look at those pre-release ACC EA videos and you´ll easily see it) I think UE4/ACC has bad scaling on graphical quality settings, low, mid settings runs worst and looks terrible then high and epic settings. On my PC´s i´ve chosen to overclock a bit the cpu and vga, over turning settings down to mid or low, seems low, mid settings on ACC really doesn´t aliviate the processes on hardware level.

 

Yeah, unfortunately the Forum scales down the resolution to much, to see it perfectliy.

But:
It's

Yes, that totally fits into the "pattern".

That's what i find, after googling "Dithering" and thats, what you can see, when the resolution is higher.^^



Thank you very much @pons and @Juliano for the enlightenment, i wish, this would be not that strong in the showroom, because of the optical impact. But with better AA, Shadow, Effect and Post Processing setting, it's gone.^^

EDIT: It seems, it highly depends on FXAA. Temporal at high eliminates almost all of this effect, but then we've got the ugly known ghosting effect...i hope, we'll get a solution for that AA problem.

 

With AA on Epic the ghosting effect disappears.

 

Tested it yesterday 2 more Hours...

With my specs, the Ghosting disappears the most at "High". At "Epic", it gets WAY worse...

I have a 1060 3GB with a Ryzen 5 1600...so it's probably more noticeable, because of less (smooth) FPS, but i have to say, the overall performance seems to be very good for a mid range system, when not maxing out everything.^^