Is there any solution for this kind of broken shadow?

Hi, i’m a green hand in UE. Can I ask is there any solution for this kind of broken shadow?

I’m not sure that’s a shadow, kind of looks like Z-Fighting, open the mesh in the static mesh viewer and see if it has any similar artifacts, if so then there’s a mesh issue.

Hi, thanks anyway. But it looks not like a z-flighting issue. It’s an original UE plane actor. Hers’s a video about how this issue happens, and i think it will occur on other users’ computers too. I know i set the plane, light and 3D view to a particular position and rotation on purpose to make this happen, and I can change the position a little to avoid this problem. But these position and rotation come from a real case of my last product rendering project. So I thinks it’s important to know what’s going on here, even tell me it’s a UE5 bug and there’s no solution. What I was wondering is if it’s just something I just set wrong.

Could you have a look at this for me, thanks.

video here:

That’s a shadow bias thing. When using real-time shadow maps it’s projecting an image away from the light source and if you have a surface that’s close to perpendicular to the light source then the pixels of the shadow map get projected across a large area and it causes artifacts. You can adjust it with the shadow bias setting for the light, or just avoid making your light perpendicular to a surface like that. Alternately, if you don’t need realtime lighting you can bake the light or if you have a GPU that supports it you can switch to ray traced shadows.

Thanks very muck. Ray Traced Shadow works.