Rip Vertices and Extend

Reference

Mode

Edit Mode

Menu

Vertex ‣ Rip Vertices and Extend

ショートカットキー

Alt-D

This tool takes any number of selected vertices and duplicate-drags them along the closest edge to the mouse. When extending an edge loop, it extends the vertices at the endpoints of the loop. The behavior is similar to the Extrude tool, but it creates an n-gon.

It helps to easily add details to existing edges.