Using a Sprite / Billboard as Foliage LOD x

How to use sprites / billboards as LOD x in the Settings of a Tree Mesh. There is only the option of auto-generating reduced meshes or of importing fbx/obj files, but no option to use one of my UE4 sprites. Even after importing an fbx there is no way to set a sprite or billboard as material.

I found it. You have to create a material and make a sprite out of it in order to put it as lod material for use with foliage tool. The sprite trees are always facing the camera as intended.
But now the sprites have different colors and the shadows are only visible at certain viewing angles.
The blueprint looks as follows.

You would have to do some Normals magic to get the light to bounce differently.

There are some speedtree nodes that can help you figure out what to do as a starting base, but some use custom nodes - so familiarity with shader code is probably a good idea.

In the end, you should try out Ryan’s Impostors script.
google shader bits Impostors
they work way better and actually take light into account much better then the standard billboard does. Obviously it’s still not perfect lighting wise. But it’s the best option in my experience.