# Pull Push
## Pull Push
The PushPull command extrudes a polysurface face to interactively add or remove volumes on the polysurface.
**Steps**
1. Select a surface.
* Curves lying on the surface can be detected for finding regions.
* Use the Invert option to swap the selected and unselected regions.
* Click on a region to toggle its selection state.
2. Move the mouse to decide the extruding direction and distance.
* The preview color changes to red if the operation is going to remove a volume from the object.
* When you enter a distance, the mouse cursor location is the positive direction.
\*The scriptable command, -PushPull, always uses the surface normal as the positive direction.
#### Command-line options
-Invert: Swaps the selected an unselected regions. The Invert option is only available when the selected surface has curves lying on it that divide the surface into three or more regions.
-Mode: The Mode option is only available when extending is possible that is when all the surrounding surfacees are planar.
* Extrude: Extrudes the selected surface without extending or shortening the surrounding surfaces.
* Extend: Extends or shortens the surrounding surfaces when extruding the selected surface.
-Toggle: Switches the operation mode between Extrude and Extend.
-Direction: Defines the direction by picking two points or typing two coordinates. The default direction is the normal direction of the selected surface.
For more information, please refer to the [Rhino documentation](https://docs.mcneel.com/rhino/8/help/en-us/commands/mesh.htm).
Pull Push
The PushPull command extrudes a polysurface face to interactively add or remove volumes on the polysurface.
