Maya 8.0 Tutorial
How to Smooth a Polygon Object in Maya
This technique can be used to smooth and round a polygon object that has been build with a small amount of geometry.
A second smoothing method involves converting your polygon object to a subdivisional surface. For information, see topic, Converting Polygons to Subdiv.
Create a polygon object or add a polygon primitive to the scene (Create > Polygon Primitives > Cube). Set the Divisions in the X, Y and Z directions to four.
Select the object and choose Mesh > Smooth. Make sure to select the smooth options.
The amount of smoothing can be controlled by adjusting the Division Levels and Continuity sliders.