CSM Cascade shadows disappear when moving camera

General Issues and Bug Reporting (Unreal Engine)
,
1

Summary

The setting r.Shadow.MaxCSMScrollingStaticShadowSubjects defaults to 5. When moving the camera along the ground, entire cluster of actors will not have shadows or their shadows will fade out too early.

Using a value of 100 for the above setting seems to be a workaround.

What Type of Bug are you experiencing?

Rendering (Graphics / Niagara)

Steps to Reproduce

  • Have lots of static or stationary actors in a small area. About 100 actors should do.
  • One directional light.
  • Scroll the camera around. Shadows will disappear, fade out too early and then pop back in.
  • No Nanite.
  • No VSM.
  • No raytracing.
  • No DFS.
  • No far shadows.
  • Only CSM.

Expected Result

Shadows should render at all times.

Observed Result

Missing shadows.

Affects Versions

5.8

Platform(s)

Windows

Upload an image

image (1).jpg
image (1).jpg1881×827 250 KB
image (2).jpg
image (2).jpg1920×843 310 KB

Additional Notes

See missing shadows in first image at the bottom.
In the second image, missing shadows on the bottom right.
Moving the camera around does not draw the shadows until you’ve moved a certain distance. You have to move it probably 300 to 1000 units before shadows change, if at all.