Foliage LODs

MELKIY

Hello guys. I've been struggling last few days trying to achieve invisible transition between tree LODs and I kinda give up. I don't know how to make decent detailed branches with also decent LODs without placing them manually. The thing is that I want as much as it possible to automate the process of creating vegetation assets.
In my case trees are made in SpeedTree with standard cross-foil leaves meshes and therefore creating LODs by replacing them (leaves meshes) with only one plane instead of current two either will result in only one additional LOD or poor quality further LODs (LOD2, LOD3 ...). What I did is I created a bunch of same planes but with larger scale and tried to repeat the shape of tree generated in SpeedTree. Then I placed this "central mesh" inside every LOD including LOD0. And to lower polycount with every next lod I gradually removed central planes from original leaves (speedtree). Unfortunately the final result is far from perfect and my sadness is doubled with the fact that I still had to make foliage manually.
So the question is : is there any good tutorial/article of fast creating of high quality vegetation assets exept for those in Wiki? Maybe you can share your techniques? Or maybe there is no fast way to do it at all? 
P.S. GTA V and many other current gen games have very visible LOD transition. Does it mean that if Rockstar couldn't make it, I especially won't be able to do that?

Steppenwolf

Speedtree lod tools are pretty solid actualy and quick to set up. I suggest you dig deeper into the documentation and study some example trees. Ther's no need to replace leaf meshes manualy. You can reduce Keep to say 0.5 for the last lod and compensate then missing meshes by adjusting Size Scale for the remaining ones. The transitions between speedtree lods are fluid so shouldn't be too obvious with the right values.
Make sure to create billboards when exporting the trees for another lod step down the line

MELKIY

Ok. Thank you. Can you say what version of speedtree supports mesh export? Because UE4 and Unity versions let you make LODs but aren't able to export meshes (I mean .obj, .fbx files and not .srt like in case with UE), and Cinema version CAN export meshes but cannot create LODs. I've read documentation and there is no information about this (or maybe I miss something). 

Steppenwolf

With export i mean the export to UE4. I know that you can't export the trees to a format that's usable in a 3D program. In the tree properties click "Make billboards" under Compile. In the exporter program (to Ue4) you can create atlases.

What is your workflow for the leaf planes/meshes? You can create them directly inside speedtree. This part of the program is a bit meh, takes some messing around to get the hang of it and figure the orientation out, but meshes made that way work best with lods and don't need any replacement meshes for lower lod. Maybe that's the part you are missing. In the materials tab select your leaf plane texture then click the Generate Mesh button.
http://i.imgur.com/NPi9557.jpg