I told about LOD only and LOD meshes. Trees LOD doesn't use meshes, only atlas texture and binary files with positions of images from atlas in a worldspace.

That is only for the farthest rendering(LOD lvl 3 and 4), LOD lvl 1 and 2 uses a simplified mesh just like the structures do. Speedtree used a 2D image for all lvls of LOD and THAT is why it looks so bad.

As an aside, the tree meshes rendered in the games before Skyrim were ALSO part of the Speedtree middleware and was the reason we couldn't produce them ourselves.

Nope, tree LOD never used meshes in any of Bethesda games. Oblivion used separate 2D images for SpeedTree trees, all games after that also use 2D images but combined on a single atlas, and binary files to specify their atlas position and locations in worldspace. They kind of transformed original Oblivion LOD system (which is also binary files with coordinates) into trees LOD only, and invented new more optimized objects LOD system that is used by this day in Fallout 4 with few changes.

Also nope, only very few trees in Fallout 3 and New Vegas used speedtree tech (Oasis ones specifically and bushes), others were ordinary nif meshes.

You can believe what I say, I wrote tree LOD generation part of FO3LODGen, FNVLODGen and TES5LODGen.

Not sure how writing LODGen makes you an authority on the objects that it uses but i'll give you the benefit of the doubt.

Can you answer this then please. If the tree meshes in Oblivion were just ordinary nif meshes then why couldn't we edit them or make new ones from scratch?

Wait, Oblivion? I was talking about Fallout 3 and it's LOD system that is still being used in later games including Fallout 4. Oblivion uses SpeedTree exclusively for all trees.

Not sure why did you mention Oblivion out of nowhere suddenly.

This topic now gets my honorable mention for the most off-the-tracks topic for Fallout 4.

Can we at least touch on the Op's original request, for where do we go after Creation Kit?