From Revit to 3ds max don't have control over vertex paint map brush paint

[DecioFurtado]

So I'm new to Max, I have been using it for only three weeks now, as an architecture student my goal is to use the Max and Corona to turn my Revit projects renders into something more photo realistic and I can see that is gonna take a lot of studying to get to that point, but I can already see some real  improvements in comparison to what I get using the Revit standard render engine.
My question is when I import the project the ground surface I created in Revit is converted to a surface-editable mesh I'm trying to scatter some trees on this surface using a Vertex Paint map in order to have some control of the trees location and density but every time I try to paint this ground surface its like the paint goes in huge patches its not localized at all, I try converting this ground surface from a Mesh to a Poly but ended up with the same results, I thought maybe I should convert it to a Plane but I can't figure out how to do it or even if that's gonna fix my issue.
Any Help would be greatly appreciated.

[romullus]

No need to convert anything, vertex paint fidelity depends on mesh density - the more dense mesh, the finer control you will have over the vertex paint. Just apply subdivide modifier to your ground mesh and adjust subdivision size to your needs.

[DecioFurtado]

Thank You very much romullus! That did the trick, I had a hunch it had something to do with the way that mesh was divided I just did not know how to divide it..... so obvious now LOL