Polygon masking in Google Earth 3D layer

[TC10]

I am inserting models in the 3D layer of Google earth to show options for development in our community.  As you can see in the attached simple example, the trees are showing in middle of uploaded buildings.

I need to be able to mask out a polygon to remove the 3D layer within a defined polygon so that the current buildings and trees within the masked area do not interfere with my uploaded building/community models.

Does anyone know if it is possible to apply this 3D Polygon mask? If not, is there a way to contact Google earth tech support to discuss?

Thanks

TC10