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Planted 200,000 trees from SpeedTree through Unity Terrain. FPS is also low. So it's just a lot of trees. But FPS was good when planting 200,000 trees from conventional models.

I had done display the billboards in edit mode, but it doesn't help. 200,000 trees on the terrane 100 sq. km. Tris 500k +, but FPS is very low.