Hello there. thx Paquito for the link, I'm trying to download, but in torrent there are no seeds, are you seeding the file? It just downloaded 1,7%.
About the OBJ trees, I generally use Blender to do them, or Arbaro http://arbaro.sourceforge.net/
, they are great and FREE
here a simple tutorial using both of them https://www.youtube.com/watch?v=uabftHFJar8
, not the best tut, but it help.
The 3D tree in Sketchup plugin looks ok but I never used, maybe in the future I will try it. https://www.youtube.com/watch?v=HnJJi2ZX1ko
A good way of creating HiRes trees is Blender with the Sapling Generator. A bit complex but with lots off control.https://www.youtube.com/watch?v=WlRF5S0aHwU
Most of the time I just use a simple tree and edit it to my taste, then I save it as .obj and keep increasing my personal library. I do the same with cars. I get free models, from Warehouse, or sites with free stuff, open then in Blender edit them to add more detail or remove interiors that we don't need and then save as .obj.
The next step it to open that tree or car (.obj) in Octane StandAlone edit them with materials, save to my library and then I can use in other projects.
with the amazing proxies option inside Octane4SU its a great way to save time using libraries.