How to get natural looking srhubs, trees and people with VUE renderings?

I am landscape architect and urgently need proper looking 3D trees and other vegetation in my landscape models. Now that Bentely doesn't support RPC cells in the new VUE rendering engine I wonder what is the new procedure to get natural looking people, trees etc. in Microstation models and how to render them efficently? There are lots of third party 3D-tree cells available but they are so large and memory consuming that using them wastes tons of time, especially if one need them more than one. And how about people? Most of 3D-models of humans look like a a 3D-model of a human.