9

1040 Chapter 9: Surface Modeling
Extrude—
Lets you extrude edges manually via
direct manipulation in the viewport. Click this
button, and then drag ver tically on any edge to
extrude it.
When extruding a vertex or edge interactively in the viewp o rt,
you set the extrusion height by moving the mouse vertically
and the base width by moving the m ouse horizontally.
Extruding an edge moves it along a normal and
creates new polygons that form the sides of the
extrusion, connect i ng the edge to t he object. The
extrusion has either three or four sides; three if the
edgewasonaborder,orfourifitwassharedby
two polygons. As you increase the length of the
extrusion, the base increases in size, to the extent
of the vertices adjacent to the extruded edge’s
endpoints.
Following are important aspects of edge extr usion:
• When over a selected edge, the mouse cursor
changes to an Extrude cursor.
• Drag vertically to specify the extent of the
extrusion, and horizontally to set the s ize of the
base.
• With multiple edges selected, drag ging on any
one extrudes all selected edges equally.
• Youcandragotheredgesinturntoextrude
them while the Extrude button is active. Click
Extrude again or ri ght-click in the active
viewport to end the operation.
Chamfer box showing extruded edge
Ex trude S ettings—Opens the Extrude Edges
dialog (page 1–1073),whichletsyouperform
extrusion via i nteractive manipulation.
If you click this button after performing a manual
extrusion,thesameextrusionisperformedonthe
current selection as a preview and the dialog opens
with Extrusion Height set to the amount of the last
manual extrusion.
Weld—Combines selected edges that fall within the
threshold sp e cified in Weld dialog (page 1–1077).
You can weld only edges that have one polygon
attached; that is, edges on a border. Also, you
cannot perform a weld operation that would result
in illegal geometry (e.g., an edge shared by more
than two polygons). For example, you cannot weld
opposite edges on the border of a box that has a
side removed.
Weld S ettings—Opens the Weld dialog (page
1–1077), which lets you s pecify the weld threshold.
Chamf e r—Click this button and then drag edges in
the active object. To chamfer vertices numerically,
click the Chamfer Settings button and change the
Chamfer Amount v alue.
If you chamfer multiple selected edges, all of
them are chamfered identically. If you drag an
unselected edge, any selected edges are first
deselected.