When creating Offset Curves, what is a requirement for the curves to offset?

For curves to be successfully offset in Siemens NX, they must lie in the same plane. This is because the offset operation is fundamentally defined by the geometric relationship between the original curve and the new curve being created at a specified distance from it. When curves are in the same plane, the software can calculate a uniform distance to create the offset curve without introducing complexities that arise from curves existing in different planes or dimensions.

If curves are not in the same plane, the definition of what the offset should be becomes ambiguous, leading to potential errors or unintended results. Hence, having the curves in the same plane is essential for ensuring a clear and accurate offset that retains the intended design integrity.