I’ll add some of my experience with this, even though it’s pretty late for the poster, might be useful for future wonderers.
Things I do with my foliage:
- Make material instances out of everything (in general, have 1-5 master materials for your whole level (With special exceptions))
- If your mesh only has one LOD by default, export it and reimport it. In this other Lod (LOD1 would be), reduce the lightmap resolution, disable casting shadows)
- If you’re far from reaching your pool limit, duplicate the textures. This is, create another texture and force the mip level to a quite low resolution with more compression or so.
- Have another master material for the lod one. Depending on the distance this gets activated and your goals, you can disable winds, surface colors, opacity masks.
- Add culling distance maximum (go to your vegetation tool, select a mesh and scroll down until you see the culling distance.
- Be smarter in vegetation placement. More =! better. A well placed vegetation system will need a lot less spawns to look suficing than a none one.
- Disable certain types of shadows (Dynamic shadows for example) on most vegetation.
- Make your level in a way that not a lot of the vegetation is rendered at once (rocks, buildings, etc).
- Improve general performance by instancing all other static meshes in your level with tools (there’s a blueprint that you can make with it :).
Hope this helps 