Unreal Engine UE5 Visual Issue

[darkevilhum]

I posted this on the UE5 forums as well but thought it was worth asking here as there's a good amount of talented devs here

I’ve been using UE5 for a few months now and I’ve noticed this issue since day one. At first I thought it was just an editor optimization or something but it seems to just get worse the more detailed my project gets.

Essentially, there is this odd warping of textures or distortion when the camera moves. I’ve tried using all different Anti Aliasing methods, and I’ve completely disabled Motion Blur, none of which made a difference.

It’s a bit hard to see in an empty scene but I wanted to illustrate that I can reproduce this by simply creating a new level, dropping the Third Person Character BP in and running. (You can see it best around the leg area here).



Does anyone know what this is? When I first noticed this, it looked more like a weird pixellation/white fuzziness around the edges of geometry as the camera panned around them, but now it looks more like stretching.

 

[osanaiko]

Modern 3d graphics pipelines are growing more and more complex. As such it's no longer the case that *all* the image calculations are completed for every frame, instead the engine might "cheat" and drop some level of detail or shader fidelity until the period of fast motion is complete, in an attempt to even out the workload or reduce load when the player probably would barely be able to see the difference anyway.

To my eye, there's a reflection of the floor grid texture that then fades out over a couple of frames.

Perhaps the shader texture of the leg surface is processed initially as a pure metallic reflective surface and then there are render passes that are scheduled after the initial frame add some additional surface effect once the motion is finished, like maybe subsurface scattering. Could even be some basic raycasted lighting effect.

You could test this theory by trying changes to the surface shader to use a simpler model and see if the weird effect persists.

 

[Dreamy3DX]

It's not a bug; increase the temporal samples and reflection capture resolution.