Question Static batching Behaviour

Hi all,

There is a lot of vegetation in the scene (I used this: https://assetstore.unity.com/packages/templates/tutorials/3d-game-kit-115747), so I marked them static.


To check whether static batching is working, I disabled them at the beginning, click "Play" button, check the profiler, then turn them on, check the profiler again (I turn on/off the static objects few times, not only once). The FPS is decreased from 150 to 75. Below is the result.

Before:


After:


In my opinion, the "draw calls" should be the same or not much different no matter I turn on/off static objects. Did I understand correctly?

UPDATE:
I tried to uncheck Static and see what difference now, and below is the result.

Uncheck Static:


As you see, Instancing is used instead of static batch. And this is ridiculous, draw calls are much lower than static batch.

Is is expected behaviour because I turn on GPU Instancing for few major materials only without custom code ?

 

Static batching shines when it can combine multiple different Objects with the same material but different meshes.
If you have the same mesh and the same material Material instancing is so much more efficient since it only does one call from the CPU to the GPU with the mesh, material and a list of where the objects should go.

 

Thanks for explanation