To Change the Curve Type
You can change free curves to planar curves and planar curves to free curves. You cannot change free curves and planar curves to curve on surface (COS).
1. In the Model Tree, right-click the Style feature that contains the curve to edit and choose Edit Definition The Style tab opens.
2. Select the curve to edit, and click Style > Curve Edit. The Curve Edit tab opens.
3. Perform one of the following actions:
Click the curve type:
planar. Select a datum plane. The curve is projected onto the selected datum plane.
curve on surface
Right-click the graphics window and choose the curve type, Free, Planar, or COS, from the shortcut menu.
4. Click .