MegaFiers Tutorial 19: Multi Volume Select
https://assetstore.unity.com/packages...
The Multi volume select modifier allows you to choose which parts of a model are deformed by your modifiers, you can add multiple volumes to build up your selection and for each volume you have control over the falloff distance outside the volume and the weight of the volume as well. You can easily position the volumes and change their sizes and if you have the selection you want and are not going to change it you can lock that in. This takes the number of selection modifiers available to four joining the normal single Volume select, the Vertex color select and the Material Select options. You can can add selection modifiers to any point in the modifier stack, so if you have an object where part of it you want to twist and another part you want to bend then that is easy to do.
More information on the system can be found on our website at www.megafiers.com