Creating a Spine

You can create a spine, that is a curve normal to a list of ordered planes or planar curves. These spines are useful when creating complex surfaces such as swept, lofted, or filleted surfaces.

This task shows you how to:

Before you begin: Create a 3D shape containing at least two planes or planar profiles and two curves.
Related Topics
Working with Multi-Sections Surfaces

Create a Spine based on Planes

You can create a spine using the planes.

  1. Click Spine in the Wireframe toolbar (Curves sub-toolbar).

    The Spine Curve Definition dialog box appears.

  2. Successively select planes or planar profiles.



  3. Click Preview.

    The spine appears.



  4. You can also select a start point.

    The point is projected onto the first plane as the spine starting point, as illustrated here (point.3 is selected) except if it is already lying onto this first plane.


    • Use the contextual menu on the Start point box to create a point.

    • If you do not select a start point (default mode) one is computed automatically.

    • To remove a selected point, select the Computed start point check box.



  5. Select one of the elements in the dialog box, then click:


    • Replace, then select the replacing element in the geometry or the specification tree
    • Remove to delete it from the spine definition
    • Add then select a new element to be added after the last one.

    Using the contextual menu, you can choose to add elements before or after the selected element.



  6. Click OK.

    The curve (identified as Spine.xxx) is added to the specification tree.

    Important: When non planar curves are selected, their mean planes are used to compute the spine.

Create a Spine based on Guide Curves

You can create a spine using the guide curves.

  1. Click Spine .

    The Spine Curve Definition dialog box appears.

  2. Click within the Guide list and successively select two guide curves.



    The spine is immediately previewed:



  3. Click OK to create the spine.

  4. The curve (identified as Spine.xxx) is added to the specification tree.

    This type of spine is very useful when creating a swept surface, as illustrated below:

    Swept surface without any spine

    Swept surface with specified spine

Reverse the Spine's Starting Direction

You can reverse the starting direction of spine using Reverse Direction.

Warning: This option can only be used if the first profile is a plane.

  1. Double-click the spine.

    The Spine Curve Definition dialog box appears.

  2. Click Reverse Direction.

  3. Click OK to create the reverse spine.