>>402529616
Utilize the terrain tree painting and make sure you only have a few variation of tree types and each tree type’s material is set to gpu instanced and make sure it has a billboard mode at a set distance and fully culled at a certain distance too for vr I use 50meters for full cull ymmv.

This is what I used for the brigade club room world. I suggest you install the unity standard asser package as it has a few trees that is well made and optimized you can copy how to make.