How to Fix Flickering or Blurry Shadows When Using Virtual Shadow Maps in UE5?

Hi everyone,

I’m using Virtual Shadow Maps (VSM) in Unreal Engine 5 for better shadow detail and compatibility with Nanite. However, I’ve been running into some issues where shadows:

  • Flicker or shimmer when the camera moves
  • Look too soft or blurry, especially on small or distant objects
  • Occasionally disappear at certain angles

Here’s my current setup:

  • Directional light with VSM enabled
  • Nanite meshes
  • Lumen active for GI
  • Shadow resolution increased in project settings

I’ve tried adjusting the light’s Shadow Bias, changing contact shadow length, and even playing with r.Shadow.Virtual.* console variables, but the results are still inconsistent.

Questions:

  • Are there recommended settings to improve stability and sharpness of shadows with VSM?
  • Is this a known limitation when using Nanite with VSM?
  • Would switching to ray traced shadows solve this, or just shift the problem?

Appreciate any advice — shadows are such a key part of my scene’s visual quality, and this issue is breaking the immersion.

Thanks!