Over 1 million trees on 15x15km terrain. How to?

Folks, I need some help how to draw a huge and dense forest on my large terrain. It requires over 1 million trees but FPS drops to 5-10 even with 400 000. I am looking for effective tools or tricks, any advice will be appreciated. The player will go there so cannot be completely replaced with forest textures.

 

• Welcome to this forum!!
• Try to add fog and 5km of camera visibility.
• Use ECS:
• Use tree game object with LOD.
• Try to use a very simple shader for distant trees without a bump mapping, reflection, metallic maps, ambient occlusion, etc...
• Add vertex ambient occlusion shadow to the mesh triangles.
• Make the shader material that do not cast or receive shadows.
• Do a unique custom simple transparent mesh that does not render but cast a shadow. face it looking the sun. Place this game object in each tree LOD. So that shadow is visible if close.

 

https://assetstore.unity.com/packages/tools/terrain/vegetation-studio-pro-131835

 

Vegetation Studio PRO did the job.