## Knife

### Cut with a knife

When wire completely crosses the face, it cuts off the face along wire. Dragging a mouse with pressing the Shift key, the face is cut off horizontally or vertically.

### Cut straight faces

It cuts off the adjacent quadrangle faces continuously. This can be used in increasing the number of the vertices with cutting a cylinder in round slices.

Please drag a mouse between the facing lines of a quadrangle. When you drag a mouse with pressing the Shift key, you can cut off joining the both center of lines.

### Erase chained lines

It behaves quite contrary to [Cut straight faces]. It combines two quadrangles first and continues to combine adjacent two quadrangles.