# Lesson 2 Creating the slag smoke

In this lesson, you set up a 3D fluid to emit from the surface of the nParticle output mesh. The fluid simulates smoke and flames that drift off the molten slag as it slides down the chute. The fluid uses Auto Resize to dynamically change the container size as it follows the slag down the chute. This keeps the fluid container to a minimal size, which decreases simulation time.

Since you do not modify the nParticle_slag object in this lesson, you can cache it to help decrease the overall simulation time. Be aware that when you continue to Lesson 3, you will need to disable the nParticle cache before starting the lesson.

#### Topics in this section

- Setting up the simulation
- Creating the fluid smoke and flames
- Setting fluid shading attributes
- Increasing the quality of the fluid simulation