Use Proximity wrap as a ProxNet deformer

You can use the Proximity Wrap deformer as a proxNet deformer to make a deforming driver geometry apply its influence relative to another deformed version of the driver, rather than its original undeformed shape.

Workflow: the armCage geometry deforms the armHi geometry using a reference driver

For example, a cage geometry is being deformed by a hi-res geometry using a Proximity Wrap deformer. Then, the cage geometry itself is being used again to deform the hi-res geometry with a Proximity Wrap deformer, but using the deformed cage as a reference to avoid double deformation.

ArmHi and armCage

1. Add a Proximity Wrap deformer to armCage. (See Create a Proximity wrap deformer.)
2. In the Attribute Editor (Ctrl + A), open the proximityWrap1 tab and pin it.
3. Select armHi, and in the Attribute Editor proximityWrap1 tab Manage Drivers menu, add armHi as a Driver.
   
   Now armCage deforms with armHi.

   
4. Unpin the Attribute Editor, select armHi, and add a Proximity Wrap deformer to it.
5. Pin the Attribute Editor proximityWrap2 tab, and add the armCage as a driver in the Manage Drivers menu.

   There is no visible change, but now armCage is used as a Reference Driver on armHi.

6. Modify armCage. The changes are transferred to armHi.