Maya 2012 Tutorial
How to Deform and Reshape Maya Objects
Deforming can be used to model and/or animate an object. Your object is connected to a deformer structure that reshapes and modifies the original geometry. If you are attempting to deform a polygon object, make sure the object has enough geometry to support the changes.
Add a polygon cube to your scene (Create > Polygon Primitives > Cube). In the Cube options set the divisions to 20 in each direction.
Using the Scale Tool, reshape the cube to look like a door.
With the object selected, choose Deform > Create Nonlinear > Bend from the Animation menu set.
Open the Outliner (Window > Outliner) and verify that the bendHandle is selected. Open the object Attribute Editor and click the Bend1 tab.
The Low Bound and High Bound settings control the start and end of the bend. Adjust the Curvature slider to deform the object. If object curves wrong direction, Use the rotate tool to re-position the deformer.
Experiment with the other deformers; Flare, Sine, Squash, Twist and Wave.
Setting Deform Keys
Each of the deform settings may be keyframed by right mouse clicking the setting name (i.e., Curvature) in the Attribute Editor and choosing Set Key from menu.
You can add multiple deformers, rotating them in different directions to achieve a variety of shapes.