Freeform Circle/Arc

Create and edit a free-form circle or arc.

A circle has a sweep angle of 360°.

An arc is a modified circle with a sweep angle of less than 360°.

Create a Free-form Circle or Arc

Create a free-form circle. You can then create an arc by changing the sweep angle to less than 360°.

  1. On the ribbon, click the Curves tab.
  2. Click the Freeform Circle/Arc icon.
  3. Drag to create the circle.
  4. Optional: To create an arc, drag the Start Angle or End Angle arrow to change the sweep angle to less than 360°.
  5. Right-click and mouse through the check mark to exit, or double-right-click.

Edit a Free-form Circle or Arc

Reposition and resize the free-form circle or arc.

  1. Double-click the free-form circle or arc.
  2. Edit the free-form circle or arc.
    To Do this
    Modify the diameter
    • Drag the free-form circle or arc.
    • Type a diameter.
    Reposition the center Drag the center.
    Modify the sweep angle
    • Drag the Start angle or End angle arrow.
    • Click the Start angle or End angle arrow, and then enter the angle.
  3. Right-click and mouse through the check mark to exit, or double-right-click.

Manipulate the Shape of a Freeform Circle/Arc

Select a degree option and then reposition or change the number of the control points in order to manipulate the shape of a freeform circle/arc.

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