Default UI Menu: Modify/Modify 3D Objects/Surface Mesh/Split Face by Isoline

Ribbon UI Menu:

This tool splits all normal faces along a common isoline (a plane cutting through the object). To Split Faces:

1. Select the tool.

2. Hover over an edge of a face, the isoline will be drawn perpendicular to the edge.

1. Click to split the faces along the isoline.

Note: Isolines do not cross merged faces.