Help plz: Imported Blender obj can not be edited with Polybrushs Vertex Paint

Hi,

i have a huge problem and i need your help.

I want to vertex paint a terrain i build in Blender, by using Polybrush in Unity. The terrain in Blender was a plain first, i extruded some faces, sculpted some smooth edges, nothing special. If i import this to Unity, it will work fine.

But: If i add a subdivide modifier again on my finished terrain in Blender, it will stop working in Unity. As you can see in Picture 1, this is my model imported to unity, with a shader which supports vertex paint. And in Picture 2 is the same model when i try to vertex paint the mesh.

From these pictures, can anyone tell me wtf is going on? i dont even know what to goole anymore. Any tips are much appreciated!

1 https://ibb.co/mF2gfyz
2 https://ibb.co/PTkDMg5

 

It's subdivide modifier. Why do you need it?

 

Just to make it look smoother. Is there another modifier i should use instead?

 

Bring your mesh into unity, and then get probuilder, select the imported mesh, then choose the option "ProBuilderize". This converts it into a probuilder object. Now you can smoothen/edit/do whatever you want to your blender mesh on Unity itself. I just learned this so I'd share this with you. But you can leverage the best of both worlds with ProBuilder and Blender and Polybrush's prefab scatter on mesh mechanic.

 

He should probably "apply" the modifier first