Material/local shading jitters during camera pulse movement

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 have a UE 5.5 repro where material or local shading details jitter during
camera movement. This may overlap with LOD, shadow filtering, material quality,
or volumetric settings, so I am treating it as lower confidence than the decal
and reflection cases.

Repro setup:

  1. UE 5.5 on Windows.
  2. Selected material/shading test map.
  3. Exact settings from the attached conditions.json.
  4. Camera pulse-translate path.

Observed result:

Local material/shading details change abruptly between adjacent frames while the
camera moves.

Expected result:

The material/shading should remain temporally stable, or any LOD/shadow
transition should be smooth and expected.

Evidence:

  • Attach evidence_sheets\31_视角移动时材质抖动.jpg.
  • Attach representative comparison video and exact settings.

Question:

What would be the best way to isolate this: disabling LOD dithering, locking
material quality, changing shadow system, or disabling volumetric features?

I also submitted this through the Unreal Engine Bug Submission Form and am using this thread to keep a public reproduction record.

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.