Primarily visible at very low internal resolutions (25-33%), the SSS checkerboard with an RGB scene colour format (r.SceneColorFormat 3) causes a double-image artefact both internally and on the silhouette of the object.
Disabling Checkerboard with SceneColorFormat 3 can lead to a very hot appearance in the SSS. Setting full resolution SSS checkboarding also doesn't alleviate the issue.
Settings SceneColorFormat to 4 does fix the issue, and SSS checkboarding can be set to 0 or 2 safely with this scene buffer format as it has an alpha.
The SSS artefact can take a second to appear, seemingly as the temporal history builds up.
The easiest method to reproduce this issue is to an existing SSS-enabled asset, such as a MetaHuman. Disable any hair or headwear that would interfere with visibility around silhouette of the skin. Heads seem to be the easiest to replicate on.
To reproduce, set scalability to High (SCALABILITY 2), which should exhibit the bug when the internal resolution is low enough. Set the override for screen resolution in the editor to 25% with TSR or TAAU.
The SSS artefact can take a second to appear, seemingly as the temporal history builds up.
If it isn't visible, try to manually set r.SceneColorFormat 3 and r.SSS.Checkerboard 1.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-226021 in the post.
| 2 |
| Component | UE - Graphics Features |
|---|---|
| Affects Versions | 5.4, 5.6, 5.5 |
| Target Fix | 5.6 |
| Created | Sep 30, 2024 |
|---|---|
| Updated | Oct 4, 2024 |