Distance Fields On or Off has no effect on Lumen. Is that correct ?

[Sebastian]

I’ve read the documentation on distance fields but there’s no Lumen word in the entire page. In the Lumen documentation there are some vague mentions but nothing clear. But if I enable it or disable it on meshes it has absolutely no effect visually.
With it ON - you can see a nice Ambient Occlusion if you activate in Visualize → Distance Field Ambient Occlusion - but other than that no effect.
I can post pictures with comparisons. Even with it Off - there are still nice indirect shadows under the objects and so on. Maybe it’s because I have hardware on - Lumen will not use distance fields ?

I wanna know for sure though, because you can get some nice shader effects if you enable it for some objects and disable it for others. Maybe it’s something I’m not seeing, or it will be used in some scenarios down the line which I don’t have yet in my scene.

EDIT:
I found these :

When enabled, the property Generate Mesh Distance Fields will be enabled, if it is not already. It is required for Lumen’s Software Ray Tracing

Software Ray Tracing

Generate Mesh Distance Fields Whether to build distance fields of Static Meshes. This is needed for Software Ray Tracing with Lumen and Distance Field Ambient Occlusion.

And so on… in some pages it is implied that it’s only used for software raytracing, but in other pages it’s not that clear that the hardware solution doesn’t need distance fields at all.

[ElectricLoft (Peter)]

I also wondered this. You have the enable it per material, you need to use the distance field ambient occlusion node and plug it into the shader. works well with lumen, I don’t see much of a performance hit.

[Arkiras]

@Sebastian

I’ve read the documentation on distance fields but there’s no Lumen word in the entire page

Because distance fields have been in the engine for a long time, many years before Lumen. They don’t exist specifically for Lumen, though I do think it should be mentioned on the docs page for UE5.

@Sebastian

it’s not that clear that the hardware solution doesn’t need distance fields at all.

With hardware raytracing it’s not necessary to have mesh distance fields. They’re disabled in the city sample project for example, which uses Lumen exclusively with hardware raytracing.