# Cutting quadrangles

This operation allows to cut one or several quadrangle elements by addition of a supplementary edge which will connect two opposite corners.

To cut quadrangles:

1. Display a mesh or a submesh in the 3D viewer.

2. In the Modification menu select the Cutting of quadrangles item or click button in the toolbar. The following dialog box will appear:

- The main list shall contain the quadrangles which will be cutted. You can click on an quadrangle in the 3D viewer and it will be highlighted. After that click the Add button and the ID of this quadrangle will be added to the list. To remove a selected element or elements from the list click the Remove button. The Sort button allows to sort the list of IDs. The Set filter button allows to apply a definite filter to selection of quadrangles.

- Apply to all radio button allows to modify the orientation of all quadrangles of the currently displayed mesh or submesh.

- Use diagonal 2-4 radio button allows to specify the opposite corners which will be connected by the cutting edge.

- Preview

- Select from set of fields allows to choose a submesh or an existing group whose quadrangle elements will be automatically added to the list.

3. Click the Apply or OK button to confirm the operation.