What will happen when you edit a spline defined Through Points to a spline defined By Poles?

When converting a spline defined Through Points to one defined By Poles, the defining data associated with the original spline configuration will not carry over. This is because splines defined By Poles use control points to dictate the shape of the spline rather than specific points that the spline must pass through. In this transformation, the precise influence of each individual point is modified, which leads to a loss of the original data that specified the exact path of the spline. Essentially, while the control points will dictate the new form, the direct constraints of the previously defined spline through those points are no longer applied, resulting in the loss of that defining data.

Understanding how spline definitions work is critical for effective modeling in CAD software—especially in applications like NX where design intention can dictate a lot about the resulting geometry.