Flickering when using medium shadow preset at 4k
Hi, is this a bug? This rendering artifacts only appear when movable directional light at near 90 degree angle(noon sunlight), using MEDIUM shadow preset, at fullscreen mode, 4k.
Lower resolutions such at 1440p/1080p do not have such artifacts. Low or High or Epic shadow preset also do not have such rendering artifacts. *edit: it only appearing on non-nanite meshes
I think it was nvidia gpu driver problem, updating to nvidia February driver seem fixed the problem.
I was wrong, the weird shadow glitches/artifacts still appearing after latest gpu driver update.
Anyone know how to fix this?
I think I found the fixes!
lowering resolutionLodBiasDirectional value to 0 or 1 removed all the shadow flickering/glitches
r.Shadow.Virtual.ResolutionLodBiasDirectional 1
Thank you for solving that. Do you know what this command is actually doing and why it is not by default with the ā0ā value?
Sorry for late reply, honestly iām dont know, it seems to lower virtual shadow map resolution lod for directional light.
Maybe light at certain angle caused VSM MaxPhysicalPages (medium preset is only 512) to overflow and flicker at 4k & medium preset, so lowering resolution lod help prevent that?
iirc the newer version likes 5.5 is default to 0 value for medium preset, and vsm seems to no longer flicker even when vsm pages overflowed, it just reduce amount of shadows being rendered