The idea came from https://www.youtube.com/watch?v=vuLf6yE406c which was sent from my colleague that using the “texture sheet animation” can let unity particle system uses an atlas as texture. That means a particle system with different “textures” can use 1 material thus 1 draw call.
In my case, I want to increase the variety of the falling leaves. My texture atlas is like following and I defined the grid like this:
To let the emitter randomize which “leaf” to emit, I input the id range to “Texture Sheet Animation”:
The emitter now emits “different textures”! Now I don’t have to duplicate emitters to create the variety.