You can use a Smooth Mesh Preview to view what a smoothed version of a mesh will look like prior to actually applying a Smooth operation to it.
Note: 
Make Live supports smooth mesh preview meshes. For more information, see
Snap to a live surface.
Make Live supports smooth mesh preview meshes. For more information, see
Snap to a live surface.
To preview a smoothed mesh using Smooth Mesh Preview
- Select the polygonal mesh(es) you want to smooth.
- Do one of the following:
- Press 1 to turn off Smooth Mesh Preview.
- Press 2 to turn on
Cage + Smooth Mesh display mode.
Maya displays the original mesh (as a wireframe cage) and the smoothed preview simultaneously, letting you select components on the either version of the mesh.
- Press 3 to turn on
Smooth Mesh display mode.
Maya only displays the smoothed preview. When you select and edit components directly on the smoothed preview, the changes are reflected back onto the original mesh.
- Press Page Up or Page Down to change the level of smoothing/subdivision that occurs on the smoothed preview.
Alternatively, you can go to the Attribute Editor for any mesh's polyShape node and turn on Smooth Mesh Preview in the Smooth Mesh section.
Note:
Caching smooth meshes can cause poor performance and consume large amounts of memory. You can disable
Smooth Mesh Preview using the
Cache Smooth Meshes option in the
Cached Playback Preferences.