Revolve is a common modeling technique similar to shaping a vase on a spinning potter’s wheel. You must first create a profile curve in an orthographic view and use the Revolve Tool to create a surface.
The points you clicked in the scene view become the control vertices (CVs) of the completed curve. CVs are points you manipulate to alter the shape of a curve (or surface). These points often lie away from the curve.
It takes a little practice to be able to predict exactly where a curve will be positioned when you click CV positions with the CV Curve Tool. Once you’ve learned the technique, you’ll be able to create and edit curves with graceful symmetry. By default, you must click at least four points to create a curve with the CV Curve Tool.
For some advanced operations in Maya, you need to know the meaning of the start of a curve and the curve direction. The start of a curve is the first CV you create when you draw the curve. It is indicated by a small hollow box at the first CV, visible as you create the curve. Curve direction is shown on the second CV after the start of the curve, indicated by a small u icon as you create the curve.