Create a Solid or Surface by Extruding

Create a 3D solid or surface by stretching curves into 3D space.

The EXTRUDE command creates a solid or surface that extends the shape of a curve. Open curves create surfaces and closed curves create solids or surfaces. See Overview of Creating Solids and Surfaces.

Options for Extrusion

When you extrude objects, you can specify any of the following options:

  • Mode. Sets whether the extrude creates a surface or a solid.
  • Specify a path for extrusion. With the Path option, create a solid or surface by specifying an object to be the path for the profile, or shape, of the extrusion. The extruded object starts from the plane of the profile and ends on a plane perpendicular to the path at the endpoint of the path. For best results, use object snaps to make sure that the path is on or within the boundary of the object being extruded.

    Extruding is different from sweeping. When you extrude a profile along a path, the profile follows the shape of the path, even if the path does not intersect the profile. Sweeping usually provides greater control and better results.

  • Taper angle. Tapering the extrusion is useful for defining part that require a specific taper angle, such as a mold used to create metal products in a foundry.

  • Direction. With the Direction option, you can specify two points to set the length and direction of the extrusion.

  • Expression. Enter a mathematical expression to constrain the height of the extrusion. See Create Geometric Relationships between Associative Surfaces.
Procedures
To extrude a NURBS surface
  1. Click Surface tabCreate panelNURBS Creation. At the Command prompt, enter convtonurbs.
  2. Click Home tabSurface panelExtrude. At the Command prompt, enter extrude.
  3. Select the objects or edge subobjects to extrude.
  4. Specify the height.

    After the extrusion, the original objects are deleted or retained, depending on the setting of the DELOBJ system variable.

To extrude a solid
  1. Click Solid tabCreate panelExtrude. At the Command prompt, enter extrude.
  2. Select the objects or edge subobjects to extrude.
  3. Specify the height.

    After the extrusion, the original objects are deleted or retained, depending on the setting of the DELOBJ system variable.

To extrude a procedural surface along a path
  1. Click Surface tabCreate panelExtrude.At the Command prompt, enter extrude.
  2. Select the objects or edge subobjects to extrude.
  3. At the Command prompt, enter p (Path).
  4. Select the object or edge subobject to use as the path.

    After the extrusion, the original objects are deleted or retained, depending on the setting of the DELOBJ system variable.

Commands
3DOSNAP

Sets the object snap modes for 3D objects.

BREP

Removes the history from 3D solids and composite solids, and associativity from surfaces.

EXTRUDE

Creates a 3D solid or surface by extending the dimensions of an object.

JOIN

Joins the endpoints of linear and curved objects to create a single object.

LIST

Displays property data for selected objects.

MEASUREGEOM

Measures the distance, radius, angle, area, and volume of selected objects or sequence of points.

REGION

Converts an object that encloses an area into a region object.

System Variables
3DOSMODE

Controls the settings for the 3D object snaps.

DELOBJ

Controls whether geometry used to create other objects is retained or deleted.

SOLIDHIST

Controls whether new composite solids retain a history of their original components.

SUBOBJSELECTIONMODE

Filters whether faces, edges, vertices or solid history subobjects are highlighted when you roll over them.

SURFACEASSOCIATIVITY

Controls whether surfaces maintain a relationship with the objects from which they were created.

SURFACEASSOCIATIVITYDRAG

Sets the dragging preview behavior of associative surfaces.

SURFACEMODELINGMODE

Controls whether surfaces are created as procedural surfaces or NURBS surfaces.