In this chapter, we learned the most important concepts and commands to create solids and surfaces from 2D objects. We learned about the EXTRUDE and PRESSPULL commands for extrusions (giving height), REVOLVE for revolving objects, LOFT for objects defined by two or more cross sections, and SWEEP to create objects by extruding along a path. These commands provide the foundation for 3D modeling. Next, we will see basic 3D shapes and object conversions.