Modifying Curves Using the Modify Curve Box

You can scale and rotate curves in a controlled way. If the curve is not planar, it is wrapped in a bounding box which is oriented to the specified plane and can be manipulated. A dashed line indicates the mean plane.

If the curve is planar, it is wrapped into a rectangle lying in the specified plane.

At the curve extremities A and B are displayed the continuities to be kept during rotation.

Before you begin: Open a 3D Shape containing a 3D curve.
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About the Robot
  1. In the work area, press Alt + middle-click on a curve and select Curve Modifier Box in the mouse menu.
    The selected curve is wrapped into a bounding box and the Curve Modifier panel opens.

  2. Move the pointer to the emphasized dashed handle on one side of the box until it is highlighted and move it to scale the curve at the selected side.


    By default, the Box Orientation is set to XY, that is it is oriented to the xy-plane of the model coordinate system and you can scale the curve in x- and y-direction.

  3. Move the pivot handle to rotate the curve around the z-axis of the xy-plane.
  4. Move the pivot in the box center.

    • Select Snap mode To Modified Curve or To All Geometries to snap the pivot to the selected curve or to any arbitrary geometry.
    • Select Pivot Inside Box to prevent the pivot to be moved outside the box.



  5. Select Continuity G0 - Free and rotate the curve.
    The pivot is set to the start curve end. The curve end point remains at its position during rotation. The pivot cannot be moved.

  6. Select Box orientation View.
    The box is oriented to the view plane. After manipulating the view, click the View option again to update the orientation.

  7. Move a side of the rectangle and an axis handle to scale and rotate the curve in the view plane.
  8. Create a user-defined OmniPlane and select Box orientation Plane.
    The bounding box is oriented to the current OmniPlane.

  9. Select Manipulation Mode Symmetry and Box orientation Global and move one side of the rectangle.
    The curve is scaled symmetrically in positive and negative direction.
  10. Select Manipulation Mode Uniform and move one side of the rectangle.
    The curve is scaled globally in x-, y-, and z-direction.