In Rhino when offsetting a curve, there is the option of BothSides / Cap. Are these also available in GH Offset? I cannot see these options in GH. New to GH. TQ.
You can cap it either afterwards by using a Cap component, or you can plug the curve into a Surface parameter ahead of time. Unfortunately there's no good way to mimic the BothSides option. You'll have to move the shape along the negative extrusion vector and then extrude it using the doubled extrusion vector.