Optimized scene still problem

Hello everyone, in my game a have a simple terrain and few models on it in the scene. Also there are trees and a directional light with hard shadows. So I want to start optimizing this, in my models, there are not too many polygons.The draw call is always around 400.
Also I don’t use a script for this scene, it’s just a terrain. And I also made a lightmapping, made all the models static & generated their UV’s. And then I baked it, it look better, also a little bit better performance but still the game can instantly drop to 10-15 Fps on a regular computer which makes the gameplay too bad. The point which makes me feel bad is there are not many things on my scene, just a terrain, couple of trees and a tower and a house model, also some little plants. Draw calls are around 400, and in the other scenes I will use more complitaced enviroment. What can I do to decrease the draw calls and also optimize it better ?

Also I tried to use occulusion culling but it’s not working, I mean I made the setup and pressed the button but nothing has changed.

Draw count is fine. It could be alpha overdraw. Here is a link with some more info: Alpha Overdraw

  1. How much foliage is in your scene?
  2. Make sure the transparent parts are not set to alpha blend.
  3. Optimize the faces with transparency on the foliage by trimming transparent areas.

Just as a test, fill the alpha channel of all your foliage textures with white then run the engine. If there is a large framerate change (40-60fps), it’s alpha-related.