Creating Splines

You can create spline curves.


Before you begin: Create a 3D shape containing several points.
  1. From the section of the action bar, click Spline .
  2. Select two or more points where the spline is to be created.
    An updated spline is visualized each time a point is selected. You can edit the spline by first selecting a point and then doing either of the following:
    • Click to add a line at the end of the list in the table.

    • Click to insert a line before the selected line in the table.

    • Click to insert a line after the selected line in the table.

    • Click to remove all the lines.
  3. Select Geometry on support and then select a support (a plane or a surface), if you want the spline to be projected onto a support surface.
    It is better when the tangent directions belong to the support, that is when a projection is possible. In this case, select a surface or plane.
    Spline created on a planar support grid

  4. Optional: Select the Close Spline check box to create a closed curve, provided the geometric configuration allows it.
    Spline with Close Spline option is cleared

    Spline with Close Spline option is selected

  5. To specify tangency conditions onto any point of the spline, select the point and click Tangent Direction in the table.
    There are two ways of imposing tangency and curvature constraints:
    • Explicit: select a line or plane to which the tangent on the spline is parallel at the selected point.

    • From curve: select a curve to which the spline is tangent at the selected point.

    Spline with a tangency constraint on endpoint (tension = 2)

    Spline with reversed tangent

  6. To set a curvature constraint at any point of the spline, once a tangency constraint is set, indicate a curvature direction and enter a radius value.
    The curvature direction is projected onto a plane normal to the tangent direction.
    Note: If you use the Create line context menu, and want to select the same point as a point already used to define the tangent direction, you may have to select it from the tree, or use the preselection navigator.
    Spline with tangency constraint

    Spline with tangency constraint and curvature constraint (radius = 50mm)

    Spline with tangency constraint and curvature constraint (radius = 2mm)

  7. Click OK to create the spline.
    The spline (identified as Spline.xxx) is added to the tree.

Important: You cannot create a spline of which points have a distance lower than the resolution.