Creo Interactive Surface Design (Style) > Connections > Curve Connections > To Change a Tangent's Directional Constraints
  
To Change a Tangent's Directional Constraints
1. Open the Style feature that contains the curve you want to edit.
2. Select a curve and perform one of the following operations:
Right-click and choose Edit Definition from the shortcut menu.
Click Style > Curve Edit.
The Curve Edit tab opens.
3. Select an endpoint to display the tangent vector for a curve with interpolation points. For curves with control points, select the control point nearest to the endpoint.
4. Perform one of the following operations:
Right-click the tangent vector and choose a tangent constraint from the shortcut menu.
Click the Tangent tab, and then select a constraint in the First or Second box.
5. On the Tangent tab, in the Drag box, select the way the tangent vector can be modified:
Free—Does not constrain the tangent direction.
Equal Length (Alt)—Applies the same length value to each active tangent when you drag multiple tangents.
Angle + Elev (Alt + Ctrl)—Locks the length so that only the angle and elevation change.
Length (Alt + Shift)—Locks the direction so that only the length changes.
 
* The drag setting does not apply constraints to the selected tangent.
6. Click .