Lumen Billboard Grass Bad Shadows in UE5

Hey Guys, I have been playing around Lumen and cannot figure out the black shadows on the grass. The shadows are disabled and I have tried different types of materials but still getting this bloby shadow noise when the grass is under shadow


try this in the console r.Lumen.ScreenProbeGather.ScreenTraces.HZBTraversal to 0
I don’t know if it works now, but it used to work.


The command works but when close It still shows dark blackish spots when near the camera. The texture works perfectly on ue4 but here it looks bad under shadow. Looks perfect when under direct light.

1 Like

Credit: Everett Gunther who helped me with this problem with that command

do r.Lumen.ScreenProbeGather.ScreenTraces.HZBTraversal=0 in your projects config folder in defaultengine.ini under rendering, if that doesn’t work go into the level blueprint and put a execute command node with r.Lumen.ScreenProbeGather.ScreenTraces.HZBTraversal 0 on begin play. tho that will require you to run it once to get rid of the lumen grass issue.

Seems im not the only one being affected by this… interesting


Hey thanks for the reply, It works for far distances but when the camera is really close to the grass it shows blacking spots. Do you know why its happening.
Also can you guide me to video/forum where Everett Gunther has mentioned this.


another one you could try this
r.Lumen.Reflections.HierarchicalScreenTraces.MaxIterations=4 which fixes shadow issues. apart from that i would say check your material cause lumen doesn’t like how their setup most of the time. good example is the megascan stuff if you see black models which is due to the way they set it up. Also check that the material isn’t blending the ao into the colour lumen hates it and check to see if these are static shadows or moveable ones? cause if its static could be a issue with your lightmaps

1 Like

Bumping because I am having the same issue in 5.0.3. My materials that are billboarded through World Position Offset all get incredibly noisy when shadowed:

But they look perfect if fully lit:

Very strange and frustrating, I have tinkered with Lumen settings, Post Process Volume settings, and my texture/sprite/flipbook settings endlessly with no luck.

turn this off, fixed it for me. All the other fixes don’t work.

1 Like

This is only working in the editor.The moment you building it it will still show it. To fix it try:

r.Lumen.ScreenProbeGather.ScreenSpaceBentNormal 0

r.Lumen.ScreenProbeGather.ScreenTraces 0


same problem still not solved, waiting for new idea

The commands just changed:


if you don’t paint your grass with the foliage tool than you are just use the grass function:


1 Like

Update: My problem is solved. All commands I found in our forum cannot totally solved. My solution is to change DirectX12 mode to DirectX11 mode in the Project Setting->Platform->Windows->Default RHI

1 Like