Converting Polygons to Subdiv
Maya 2012 Tutorial
How to Convert Polygon Object to Subdivisional Object in Maya
Start by building your shape as a simple polygon object. This shape defines the basic geometry. By converting your polygon to a subdiv surface, the object now becomes much more organic.
Add a polygon plane to the workspace (Create > Polygon Primitives > Plane). In the plane options, set the Divisions to six for both directions.
With your object selected, click the Component Mode icon and click the Vertices icon.
Using the Selection, Move and Scale modes, reshape the object by moving and scaling groups and individual vertices. Use the various views as you move the vertices to re-shape the object. In this example we also selected the Face icon and deleted some of the faces.
Return to the object mode by clicking the Object Mode icon. With the object selected, choose Modify > Convert > Polygons to Subdiv.