Warp > Using Warp > To Preserve Analytic Geometry
  
To Preserve Analytic Geometry
Creo tries to preserve analytic surfaces (planes, cylinders, and others) whenever it is possible. Turning on the Use Boundary Tangents option increases the chance of success to keep the surfaces analytic.
To turn on this option:
While the Warp tool is open, right-click the graphics window, and choose Use Boundary Tangents from the shortcut menu.
Using this option to maintain tighter tangency might cause slower regeneration of a Warp feature.