To Offset a Curve Along a Surface
1. Perform one of the following actions:
◦ Select a curve, and click > 
Offset.
Offset.◦ Click > Offset, click 
Curve, and then select a curve.
Offset, click Curve, and then select a curve.The selected curve appears in the Offset curve collector on the References tab.
 | If you are using a chain set as a reference and you want to modify it, click Details on the References tab and use the Chain dialog box. |
2. Under Offset Method, select 
Along Surface to offset the curve in the direction along the reference surface.
Along Surface to offset the curve in the direction along the reference surface.3. Click the 
reference quilt collector and select a quilt or surface to act as a reference for the offset curve. By default, the quilt or surface on which the offset curve is located is selected as the reference.
reference quilt collector and select a quilt or surface to act as a reference for the offset curve. By default, the quilt or surface on which the offset curve is located is selected as the reference.4. Enter an offset value in the 
Offset box.
Offset box.5. Click 
to flip the direction of the offset, if necessary.
to flip the direction of the offset, if necessary.6. On the Measurements tab, specify the measurement type as either 
(normal to curve) or 
(parallel to plane). If you select , you must select a reference plane.
(normal to curve) or (parallel to plane). If you select , you must select a reference plane.7. Click 
OK to complete the offset curve.
OK to complete the offset curve.