SSR Quality Regression


  • Add huge flat plane with Roughness of 0 to level
  • Enable SSR
  • Notice huge artifacts near skyline (shallow angle)

Hi dgrieshofer,

I tested this issue using the steps provided in a blank project with starter content. All I have is a plane with material roughness at 0 and some chairs on top to see the reflection. I didn’t get the dark artifact like in your screenshot though. (see screenshot)

Can you reproduce this issue with minimal assets? This could possibly be an issue with the material used.

Thank you for your time,

Hi Ed, I am also able to reproduce this with a very simple material as can be seen in the following screenshot:

You need to place the camera very close to the plane and look up. It might help to place objects in the distance (~50000uu away) and make the plane even bigger to be able to see it easier. Also happens with other angles/distances but this is the easiest to reproduce.

Thank you for the clarification! This helped a lot since the test asset I used was too small to get the dark artifact to appear. I appreciate your willingness to assist in this investigation.

I have logged a bug report on this issue and it has been labeled as a regression. You can view it here: Unreal Engine Issues and Bug Tracker (UE-35128)

I’ll also attach the same screenshot attached to the bug report since you can’t view it there.


, for the record since I have seen that there were some recent SSR optimizations which might have caused this issue and you could argue that SSR is not made for large flat planes I would like to mention that the artifacts only depend on the view angle. It also happens for example on the side of a 1000x1000x1000 flat cube when the camera is placed almost parallel to the side of the cube (so that you can still see it) and being rotated away slightly.

Hey, i think im having the same problem as this. object appear black in the reflections and i get lots of “dots” on the edges of the object in the reflection. Any fix yet? (Im using custom build of UE4 4.17 VXGI)