To follow this recipe, you need to have a particle system and a tree created with Unity's built—in Tree Creator. You can open the provided example project and go to the Chapter 07 Special effectsRecipe 06 Using wind emitters to create motion for foliage and particle systems directory. In the Example.unity scene there, you can find a tree and a simple particle system (falling leaves). Play the game to see the tree and particles moving with the wind.