Deselect Similar (ver. 0.4)

This is an add-on for Blender.
Бж for blender 2.83 or later. (I guess the add-on can be used in 2.80 or later, but recommend 2.83 or later.)

This add-on expands a function of "Select Similar" to get the difference or intersection of
"Currently selected elements(vertices, edges, or faces)" and
"Elements to be selected by select similar".

This is a sort of wrapper.
First, the addon memorizes state of selection, and then calls select similar, and then reselects elements with above rule.

2020.09.26 ver 0.3
2021.07.11 ver 0.4 Select all children.

Install

Download the packaged and unpack.
And then install DeselectSimilar.py as usual.

БжБjYou can not install DeselectSimilar as zipped folder. You must unpack at first, and install DeselectSimilar.py itself.

How to Use

Edit Mode

When installed, Deselect Similar menu is added to the select menu in edit mode.

For example, after selecting an area with select similar and...

Use deselect similar with substract mode, you can get donut-like selection area.

Select Similar uses "all selected elements" to comparison.
But that is meaningless for deselection.
Thus, a single element (active one, or last selected one) is used for deselection.

Note 1) No shortcut is added. Add it by hands if needed.

The name of menu is MESH_MT_SubmenuDeselectSimilar.
Thus, the sample of shortcut is as below.

Note 2) This addon is for edit of single object.
It does not work properly when multiple objects are in edit mode.

Object Mode

"Select All Children" would be added to select menu.

All chilrens would be selected.

This is a simple extension of "select grouped".
Select grouped function select children of single active object.
Insteadly, "Select All Children" select children of all selected objects.