- Run this Polygon Select add-in in 3D view (top of view cube only), floor plan, or ceiling plan view.

- Draw a polygon shape then the elements will be selected in this polygon area.

- Inside Method: Elements are completely within the boundary of the polygon.

- Intersect Method: Elements are wholly or partially within the boundary of the polygon.

* If there are elements that are already selected before running this app, they will be added in this app selection.

* The line segments of the polygon must not be intersecting.

The installer that ran when you downloaded this app/plug-in from Autodesk App Store will start installing the app/plug-in. OR, simply double-click the downloaded installer to install the app/plugin. To uninstall this plug-in, exit the Autodesk product if you are currently running it, simply rerun the installer, and select the "Uninstall" button. OR, click Control Panel > Programs > Programs and Features (Windows 7/8.1/10) and uninstall as you would any other application from your system.

It's second version and added Autodesk® Revit® 2021 support.