Some functions, such as Surfaces > Revolve 
create an object that has construction history. The construction history of an object that is being transformed cannot be maintained.
A confirmation box appears, asking if you wish to continue even though the construction history will be removed:
- If you select YES, the construction history is deleted and you can proceed with the operation.
- If you select NO, the operation is canceled and the construction history is kept.
Select Undo at any time to reset the geometry to its original values (without construction history).
Any continuity present in the model is lost by this deformation and you will have to rebuild the surface. If you keep the deformations relatively small, the resulting continuity may work for presentation only.
Construction history enables curves or surfaces to adjust to changes in the geometry of the objects that generate them. If construction history is lost, to update the generated objects you must re-create them.