For the smoke simulation in this lesson, you create an nParticle system composed of an nParticle object, an emitter object, and a nucleus node. You will add a Volume Axis field to your effect to create turbulence and swirling in the nParticle smoke. This field helps create the realistic behavior of smoke as it cools, rises and dissipates. To finish your smoke simulation, you will also add a Nucleus Wind force to make the smoke drift as it disappears.