Use polygon tools to modify a subdivision surface

User Guide > Modeling > Subdivision Surfaces > Editing subdivision surfaces >

In addition to working on a subdivision surface when it is displayed in its normal subdivision mode (standard mode), Maya lets you modify a subdivision surface as if it were a polygon mesh by creating a substitute (proxy mesh) for you to edit (“polygon proxy mode”).

Working with a subdivision surface in polygon proxy mode lets you use the many polygon editing tools in Maya to modify and edit your subdivision surface. You can easily switch back and forth between the two display modes while you work on the surface.

To...	Do this
Switch to polygon proxy mode.	Choose Subdiv Surfaces > Polygon Proxy Mode. Maya creates polygonal mesh proxy from the current subdivision level. Use the polygon tools to edit the proxy.
Switch back to standard mode.	Choose Subdiv Surfaces > Standard Mode. Maya applies changes you made to the proxy to the subdivision surface.

To...

Do this

Switch to polygon proxy mode.

Choose Subdiv Surfaces > Polygon Proxy Mode.

Maya creates polygonal mesh proxy from the current subdivision level. Use the polygon tools to edit the proxy.

Switch back to standard mode.

Choose Subdiv Surfaces > Standard Mode.

Maya applies changes you made to the proxy to the subdivision surface.

Notes

The proxy mesh has no shading so you can see the resulting subdivision surface.
Boolean, Bevel, and Reduce operations will not maintain standard mode edits.
Some polygonal operations (for example, Combine) create a new polygonal surface which has no subdivision surface associated with it. You will have to create a new subdivision surface from the resulting polygonal surface.
Some polygonal operations modify your Standard mode edits. For example, when subdividing a face in polygon proxy mode, the original standard mode edits are copied onto each of the new faces. Edits and creases away from the modified area are not affected.
Avoid changing the topology, such as subdividing a face, in areas where you’ve edited components in Standard mode. Doing this can alter the surface in unexpected ways. This is not a problem for edits to level 0 components, only at finer levels.

Troubleshooting polygon proxy mode

I can’t switch to polygon proxy mode?

If you’ve used deformers, mapped UVs with history, or created other construction history while in Standard mode, you cannot switch to Polygon Proxy mode.

First delete construction history on the object ( Edit > Delete by Type > History), then try switching to Polygon Proxy mode.