Context: this report comes from a RenderFuzz-based UE 5.5 rendering anomaly study. I am posting the issue publicly so other Unreal Engine developers can check whether it is reproducible, already known, or has a practical workaround.
I found a repeated UE 5.5 rendering artifact where TAA + Screen Space GI creates speckled noise that flickers over time on indirectly lit surfaces.
Repro setup:
- UE 5.5 on Windows.
- Deferred renderer.
- r.AntiAliasingMethod=2.
- r.DynamicGlobalIlluminationMethod=2.
- Slow camera rotation/translation in a map with rough surfaces receiving indirect light.
Observed result:
The affected surfaces show sparkling/speckled noise that changes from frame to frame. It is not just a static noisy texture; the pattern is temporally unstable.
Expected result:
Screen Space GI should not produce obvious frame-to-frame speckle flicker on stable surfaces during slow camera movement.
I attempted to submit this through the Unreal Engine Bug Submission Form, but the submission is currently blocked at the site’s human-verification step. I am using this thread to keep a public reproduction record while I continue trying to get the official form accepted.
Attachment note: I attempted to attach video_comparison.mp4 here, but this forum account is currently blocked by the forum’s new-user attachment restriction. The representative video was attached to the Unreal Engine Bug Submission Form submission and can be provided again when the forum allows attachments.