Extrude

Extrude a curve to create a 3D surface, or extrude a surface to create a solid. You can perform the same extrusion on multiple objects at a time.

Tip: If you have extruded nested curves (closed curves and their offsets or concentric curves), make sure that you are using flat caps, and that no drafting options are enabled.

Create an Extrusion

Extrude a curve to create a 3D surface, or extrude a surface to create a solid. You can perform the same extrusion on multiple objects at a time.

  1. On the ribbon, click the Surfaces tab.
  2. Click the Extrude icon.

  3. Select the curves and surfaces. Right-click to confirm.
    • To simultaneously select adjacent edges, hold down Shift while clicking.
    • To select a single curve or edge when the two are tangent to each other, hold down Alt while clicking.
    By default, the curve or surface is extruded by 1 unit in the normal direction, in the positive direction of the active plane.
  4. Optional: See Step 2 of Edit an Extrusion.
  5. Right-click and mouse through the check mark to exit, or double-right-click.

Edit an Extrusion

Reselect objects to extrude, change the extrusion direction and length, add or remove caps, create a secondary extrusion, define the upper limit using a reference body, and create a scaled extrusion.

  1. Double-click the extrusion to enter edit mode.
  2. Edit the extrusion (see below).
    To Do this Notes
    Reselect objects to extrude
    1. In the guide bar, click Objects.
    2. Click the objects you want to add or remove.
    3. Right-click to confirm.
     
    Invert the extrusion direction
    • In the guide bar, click the Invert icon.
    • In the Control Panel, click the Invert Direction button.
     
    Change the extrusion direction In the Control Panel, select one of the following options:
    • Global Axis X: Extrude along the global x-axis.
    • Global Y: Extrude along the global y-axis.
    • Global Z: Extrude along the global z-axis.
    • Ref Geometry: Set the extrusion direction by clicking a reference geometry.
    • Normal: Extrude in the normal direction.
    • Custom: Extrude in a custom direction by doing one of the following:
      • Drag the axis arrows.
      • Drag the direction point.
      • Click an arrow, and then type a rotation distance.
     
    Add a secondary extrusion
    • Drag the secondary extrusion arrow.
    • Click the text box along the secondary extrusion, and then type a length.
     
    Add a secondary extrusion that is symmetric In the guide bar, click Symmetric Direction.  
    Add or remove caps
    1. In the guide bar, select Caps.
    2. Hover over primary or secondary extrusion arrow, and then click the round or flat cap icon.
    You cannot use a round cap with a scaled extrusion.
    Change the cap elevation
    • Drag the blue plus icon at the end of the extrusion.
    • Click the text box near the blue plus icon, and then type an elevation.
     
    Change the extrusion length
    • Drag the primary or secondary distance arrow.
    • Click the text box along the primary or secondary distance, and then type a length.
     
    Define the upper limit of the extrusion using a reference body
    1. Hover over the length arrows, click the Up to Body icon, and then click a reference body.
    2. To trim the reference body with the extrusion, hover over the Up to Body icon, and click one of the following icons:
      • Trim and keep inside: Remove the extraneous material, leaving a cap.
      • Trim and keep outside: Remove the cap, leaving the extraneous material.
    The reference body must extend over the extrusion completely; otherwise, the extrude operation will fail. The reference body can be a NURBS or PolyNURBS object with one face or multiple faces; note that choosing a complex reference body will take more processing time.
    Create a scaled extrusion, which is smaller at one end and larger at the other In the Control Panel, select Draft1 or Draft2, and then type an angle.

    To invert the draft angles, select Invert Draft value.

    To create a smooth surface between the primary and secondary extrusions, use the same draft angle, and then invert either extrusion.

    You cannot use a round cap with a scaled extrusion.

  3. Right-click and mouse through the check mark to exit, or double-right-click.

Manipulate the Shape of an Extrusion

Select a degree option and then reposition or change the number of the control points in order to manipulate the shape of an extrusion.

In the guide bar, Exact is selected by default. It is used to achieve precise dimensions when you don't plan to manipulate the shape.

If you want to manipulate the shape, select one of the degree options.

  1. In the guide bar, select NURBS Degree 2, 3 or 5.
    Note: Select a higher degree for a smoother curvature.
  2. Modify the control points.
    To Do this
    Change the number of points In the guide bar, enter the number of Points.
    Reposition a point
    • Drag a point.
    • Click a point, and then enter the x, y, and z coordinates.
    Modify multiple points
    • Click a blue line, and then drag one of the selected points.
    • Box select the points, and then drag one of the selected points.
    Undo changes for selected points Click the points you want to revert, and then in the guide bar, select Un-edit selected.
  3. Right-click and mouse through the check mark to exit, or double-right-click.


Figure 1. Exact


Figure 2. Degree 3