Unfortunately, I cannot use vertex paint because the meshes I would paint on are HLODs spawned from a blueprint and vertex painting does not to work on those.
I think the sampling regions section is only for skeletal meshes since I cannot find it in the static mesh editor.
I am trying to get moss on top of the rocks that I spawn in the blueprint. I think I will try to spawn moss clumps when I spawn the rock in the blueprint.
Thank you for your help