Extruding Polygon Faces
Maya 2012 Tutorial
How to Add Geometry to Maya Polygon Object by Extruding Faces
Starting with a simple polygon object, you can extrude the faces to add more geometry. This technique is quite helpful in creating a basic structure that can be converted to a subdivision surface to create a smoother, more organic shape.
Add a polygon cube to the workspace. Set the x, y and z divisions to one. (Create > Polygon Primitives > Cube).
Switch to the Component Mode and activate the Face Selection. To select the top face, click the center of the face.
Using the Polygons menu set, choose Edit Mesh > Extrude. Notice the arrows and scale boxes now available.
Click and drag the arrows (to move) or the scale boxes (to scale) the new geometry. Press g to accept the change and begin another extrusion. To exit, press the q key to return to the Select Tool.
Keeping Faces Together
The menu item, Edit Mesh > Keep Faces Together (Polygons Menu set) works along side the Extrude tool. If the menu item is not selected and you extrude several connected faces, the result is a series of non-connected faces. This might be great if you're extruding polygon faces that define a hand to create the fingers, yet for the most part it is best to leave this menu item with its default setting, which is checked.