Adding Curvature to Splines In the graphics area, select one of the splines, then press Ctrl and select the adjacent construction line. In the PropertyManager, under Add Relations, click Tangent , then click . Repeat steps 1 and 2 with the other spline and the adjacent construction line. Parent topic3D Sketching with Planes Previous topic Redefining the Splines Next topic Completing the Addition of Curvature