These renders took about 25 minutes, 150 dpi, 2000 pixels in the bigger side, I used the “Final” preset.
Later on I discovered some other option under the atmosphere editor menu, activating global radiosity gives a new fell to the renders. I´m using Vue 7, I think there´s not radiosity on earlier versions.
That´s a nice concept!!
I thought about it a little and came to a solution I may end using on my own final thesis for school: Use water channels as rails, the trees and shrubs would float on their boxes and be rearrangeable.