Set Imported Mesh as Landscape for Painting?

How can I tell UE4 that the mesh i imported is a landscape mesh so i can paint the shader onto it in UE4.

I made a height map from a google maps image in Photoshop, then displaced the geometry in Cinema 4d. This way i can measure everything and i know its the right size. Using the height map in World Machine or UE4 was giving crazy results. Also I could use the google image as something to paint over or reference.

Iv tried using the paint tool next to the landscape tool but nothing happens when i click.

Iv managed to vertex paint with a lerp :frowning: but its not enough layers for what im trying to do.

everything you need for basic stuff is in the docs

i dont know how to fix it in ue4 yet but this is what its doing by default.